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•	federal and state regulatory or governmental actions, including the impact of energy, tax, financial and health care legislation, and of regulatory agency orders;

•	IPL’s and WPL’s ability to obtain adequate and timely rate relief to allow for, among other things, the recovery of fuel costs, operating costs, transmission costs, deferred expenditures, capital expenditures, and remaining costs related to EGUs that may be permanently closed, earning their authorized rates of return, and the payments to their parent of expected levels of dividends;

•	the ability to continue cost controls and operational efficiencies;

•	the impact of IPL’s retail electric base rate freeze in Iowa during 2016;

•	the impact of WPL’s retail electric and gas base rate freeze in Wisconsin during 2016;

•	weather effects on results of utility operations, including impacts of temperature changes in IPL’s and WPL’s service territories on customers’ demand for electricity and gas;

•	the impact of the economy in IPL’s and WPL’s service territories and the resulting impacts on sales volumes, margins and the ability to collect unpaid bills;

•	the impact of customer- and third party-owned generation, including alternative electric suppliers, in IPL’s and WPL’s service territories on system reliability, operating expenses and customers’ demand for electricity;

•	the impact of energy efficiency, franchise retention, customer- and third party-owned generation and customer disconnects on sales volumes and margins;

•	the impact that price changes may have on IPL’s and WPL’s customers’ demand for electric, gas and steam services and their ability to pay their bills;

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developments that adversely impact the ability to implement the strategic plan, including unanticipated issues with new environmental control equipment for various fossil-fueled EGUs of IPL and WPL, IPL’s construction of Marshalltown, WPL’s proposed Riverside expansion, various replacements, modernization and expansion of IPL’s and WPL’s electric and gas distribution systems, Resources’ electricity output and selling price of such output from its Franklin County wind farm, and the potential decommissioning of certain EGUs of IPL and WPL;

•	issues related to the availability and operations of EGUs, including start-up risks, breakdown or failure of equipment, performance below expected or contracted levels of output or efficiency, operator error, employee safety, transmission constraints, compliance with mandatory reliability standards and risks related to recovery of resulting incremental costs through rates;

•	disruptions in the supply and delivery of natural gas, purchased electricity and coal, including due to the bankruptcy of coal mining companies;

•	changes in the price of delivered coal, natural gas and purchased electricity due to shifts in supply and demand caused by market conditions and regulations, and the ability to recover and to retain the recovery of related changes in purchased power, fuel and fuel-related costs through rates in a timely manner;

•	impacts on equity income from unconsolidated investments due to potential changes to ATC’s authorized return on equity;

•

issues associated with environmental remediation and environmental compliance, including compliance with the Consent Decree between WPL, the EPA and the Sierra Club, the Consent Decree between IPL, the EPA, the Sierra Club, the State of Iowa and Linn County in Iowa, the CCR rule, future changes in environmental laws and regulations, including the EPA’s regulations for CO2 emissions reductions from new and existing fossil-fueled EGUs, and litigation associated with environmental requirements;

•	the ability to defend against environmental claims brought by state and federal agencies, such as the EPA, state natural resources agencies or third parties, such as the Sierra Club, and the impact on operating expenses of defending and resolving such claims;

•	the ability to recover through rates all environmental compliance and remediation costs, including costs for projects put on hold due to uncertainty of future environmental laws and regulations;

•	impacts that storms or natural disasters in IPL’s and WPL’s service territories may have on their operations and recovery of, and rate relief for, costs associated with restoration activities;

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•	the direct or indirect effects resulting from terrorist incidents, including physical attacks and cyber attacks, or responses to such incidents;

•	the impact of penalties or third-party claims related to, or in connection with, a failure to maintain the security of personally identifiable information, including associated costs to notify affected persons and to mitigate their information security concerns;

•	the direct or indirect effects resulting from breakdown or failure of equipment in the operation of gas distribution systems, such as leaks, explosions and mechanical problems, and compliance with gas distribution safety regulations, such as those that may be issued by the Pipeline and Hazardous Materials Safety Administration;

•	risks associated with integration of a new customer billing and information system, which was completed in the first quarter of 2016;

•	impacts of IPL’s future tax benefits from Iowa rate-making practices, including deductions for repairs expenditures and allocation of mixed service costs, and recoverability of the associated regulatory assets from customers, when the differences reverse in future periods;

•	any material post-closing adjustments related to any past asset divestitures, including the sales of IPL’s Minnesota electric and natural gas assets, RMT and Whiting Petroleum, which could result from, among other things, warranties, parental guarantees or litigation;

•	continued access to the capital markets on competitive terms and rates, and the actions of credit rating agencies;

•	inflation and interest rates;

•	changes to the creditworthiness of counterparties with which Alliant Energy, IPL and WPL have contractual arrangements, including participants in the energy markets and fuel suppliers and transporters;

•	issues related to electric transmission, including operating in Regional Transmission Organization energy and ancillary services markets, the impacts of potential future billing adjustments and cost allocation changes from Regional Transmission Organizations and recovery of costs incurred;

•	current or future litigation, regulatory investigations, proceedings or inquiries;

•	Alliant Energy’s ability to sustain its dividend payout ratio goal;

•	employee workforce factors, including changes in key executives, collective bargaining agreements and negotiations, work stoppages or restructurings;

•	access to technological developments;

•	changes in technology that alter the channels through which electric customers buy or utilize power;

•	material changes in retirement and benefit plan costs;

•	the impact of performance-based compensation plans accruals;

•	the effect of accounting standards issued periodically by standard-setting bodies, including a new revenue recognition standard, which is currently expected to be adopted in 2018;

•	the impact of changes to production tax credits for wind farms;

•	the impact of adjustments made to deferred tax assets and liabilities from state apportionment assumptions;

•	the ability to utilize tax credits and net operating losses generated to date, and those that may be generated in the future, before they expire;

•	impacts of the extension of bonus depreciation deductions;

•	the ability to successfully complete tax audits and changes in tax accounting methods with no material impact on earnings and cash flows; and

•	factors listed in MDA and Item 1A Risk Factors.

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(a)	The average cost of natural gas includes commodity and transportation costs as well as realized gains and losses from swap and option contracts used to hedge the price of natural gas volumes expected to be used by IPL’s and WPL’s natural gas-fired EGUs.

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(a)

In 2015, Alliant Energy sold its electric distribution assets in Minnesota to Southern Minnesota Energy Cooperative. At the date of the sale, Alliant Energy had approximately 42,000 electric retail customers in Minnesota. Prior to the asset sale, the electric sales to these retail customers are included in residential, commercial and industrial retail sales. Subsequent to the asset sale, the related electric sales are included in wholesale electric sales pursuant to a wholesale power supply agreement between IPL and Southern Minnesota Energy Cooperative, which is discussed in Note 3.

(b)	Cooling degree days are calculated using a simple average of the high and low temperatures each day compared to a 65 degree base. Normal degree days are calculated using a rolling 20-year average of historical cooling degree days. Refer to “Gas Utility Operations” below for details of heating degree days.

(c)	2013 MWhs include replacement energy provided under the Kewaunee PPA after Kewaunee was shut down in May 2013.

(d)	All or some of the renewable energy attributes associated with generation from these sources may be used in future years to comply with renewable energy standards or other regulatory requirements, or sold to third parties in the form of renewable energy credits or other environmental commodities.

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(a)

In 2015, IPL sold its electric distribution assets in Minnesota to Southern Minnesota Energy Cooperative. At the date of the sale, IPL had approximately 42,000 electric retail customers in Minnesota. Prior to the asset sale, the electric sales to these retail customers are included in residential, commercial and industrial retail sales. Subsequent to the asset sale, the related electric sales are included in wholesale electric sales pursuant to a wholesale power supply agreement between IPL and Southern Minnesota Energy Cooperative, which is discussed in Note 3.

(b)	Cooling degree days are calculated using a simple average of the high and low temperatures each day compared to a 65 degree base. Normal degree days are calculated using a rolling 20-year average of historical cooling degree days. Refer to “Gas Utility Operations” below for details of heating degree days.

(c)	All or some of the renewable energy attributes associated with generation from these sources may be used in future years to comply with renewable energy standards or other regulatory requirements, or sold to third parties in the form of renewable energy credits or other environmental commodities.

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(a)	Cooling degree days are calculated using a simple average of the high and low temperatures each day compared to a 65 degree base. Normal degree days are calculated using a rolling 20-year average of historical cooling degree days. Refer to “Gas Utility Operations” below for details of heating degree days.

(b)	2013 MWhs include replacement energy provided under the Kewaunee PPA after Kewaunee was shut down in May 2013.

(c)	All or some of the renewable energy attributes associated with generation from these sources may be used in future years to comply with renewable energy standards or other regulatory requirements, or sold to third parties in the form of renewable energy credits or other environmental commodities.

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(a)	In April 2015, Alliant Energy sold its natural gas distribution assets in Minnesota. At the date of the sale, Alliant Energy had approximately 11,000 gas retail customers in Minnesota.

(b)	Heating degree days are calculated using a simple average of the high and low temperatures each day compared to a 65 degree base. Normal degree days are calculated using a rolling 20-year average of historical heating degree days.

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(a)	In April 2015, IPL sold its natural gas distribution assets in Minnesota. At the date of the sale, IPL had approximately 11,000 gas retail customers in Minnesota.

(b)	Heating degree days are calculated using a simple average of the high and low temperatures each day compared to a 65 degree base. Normal degree days are calculated using a rolling 20-year average of historical heating degree days.

(a)	Heating degree days are calculated using a simple average of the high and low temperatures each day compared to a 65 degree base. Normal degree days are calculated using a rolling 20-year average of historical heating degree days.

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(a)	Base load EGUs (BL) are designed for nearly continuous operation at or near full capacity to provide the system base load. Intermediate EGUs (IN) follow system load changes with frequent starts and curtailments of output during low demand. Peak load EGUs (PK) are generally low efficiency, quick response units that run primarily when there is high demand.

(b)	Based on the accredited generating capacity of the EGUs included in MISO’s resource adequacy process for the planning period from June 2015 through May 2016.

(c)	Represents IPL’s 48% ownership interest in this 726 MW (nameplate capacity) / 675 MW (generating capacity) EGU, which is operated by IPL.

(d)	Refer to “Strategic Overview” in MDA for discussion of EGUs that may be retired or changed from coal-fired to an alternative fuel source in the next few years.

(e)	Represents IPL’s 25.695% ownership interest in this 696 MW (nameplate capacity) / 602 MW (generating capacity) EGU, which is operated by MidAmerican Energy Company.

(f)	Represents IPL’s 28% ownership interest in this 584 MW (nameplate capacity) / 477 MW (generating capacity) EGU, which is operated by MidAmerican Energy Company.

(g)	Represents IPL’s 4% ownership interest in this 812 MW (nameplate capacity) / 728 MW (generating capacity) EGU, which is operated by MidAmerican Energy Company.

(h)	The fuel type at M.L. Kapp Unit 2 was switched from coal to natural gas in 2015.

(i)	Generating capacity represents 16% of the capacity of this wind farm based upon the MISO resource adequacy process, which is determined separately for each wind farm, during the planning period from June 2015 through May 2016.

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(a)	BL are designed for nearly continuous operation at or near full capacity to provide the system base load. IN follow system load changes with frequent starts and curtailments of output during low demand. PK are generally low efficiency, quick response units that run primarily when there is high demand.

(b)	Based on the accredited generating capacity of the EGUs included in MISO’s resource adequacy process for the planning period from June 2015 through May 2016.

(c)	Represents WPL’s 46.2% ownership interest in this 1,112 MW (nameplate capacity) / 1,080 MW (generating capacity) EGU, which is operated by WPL.

(d)	Represents WPL’s 68.2% ownership interest in this 351 MW (nameplate capacity) / 299 MW (generating capacity) EGU, which is operated by WPL.

(e)	Refer to “Strategic Overview” in MDA for discussion of EGUs that may be retired in the next few years.

(f)	Represents Units 2 and 3, which WPL owns. WPL also operates South Fond du Lac Combustion Turbines Units 1 and 4.

(g)	Generating capacity represents 14% of the capacity of this wind farm based upon the MISO resource adequacy process, which is determined separately for each wind farm, during the planning period from June 2015 through May 2016.

(h)	Generating capacity represents 12% of the capacity of this wind farm based upon the MISO resource adequacy process, which is determined separately for each wind farm, during the planning period from June 2015 through May 2016.

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(a)	All shares were purchased on the open market and held in a rabbi trust under the DCP. There is no limit on the number of shares of Alliant Energy common stock that may be held under the DCP, which currently does not have an expiration date.

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(a)	Refer to “Results of Operations” in MDA for discussion of the 2015, 2014 and 2013 results of operations.

(b)	In 2015, Alliant Energy adopted a new accounting standard related to the presentation of debt issuance costs on the balance sheet, which was applied retrospectively. As a result, “Total assets at year-end” and “Long-term obligations, net” were revised to conform to the new presentation. The impact to 2013, 2012 and 2011 was not material. Refer to Notes 1(p) and 1(q) for further details.

(c)	Represents the sum of income from continuing operations before income taxes plus interest expense, divided by interest expense.

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(a)	Refer to “Results of Operations” in MDA for a discussion of the 2015, 2014 and 2013 results of operations.

(b)

In 2015, IPL adopted a new accounting standard related to the presentation of debt issuance costs on the balance sheet, as well as applied a change in method of recording income taxes, which were applied retrospectively. As a result, “Net income,” “Earnings available for common stock,” “Total assets,” and “Long-term obligations, net” were revised to conform to the new presentation. The impact to 2013, 2012 and 2011 was not material. Refer to Notes 1(c), 1(p) and 1(q) for further details.

(a)	Refer to “Results of Operations” in MDA for a discussion of the 2015, 2014 and 2013 results of operations.

(b)

In 2015, WPL adopted a new accounting standard related to the presentation of debt issuance costs on the balance sheet, as well as applied a change in method of recording income taxes, which were applied retrospectively. As a result, “Net income,” “Earnings available for common stock,” “Total assets,” and “Long-term obligations, net” were revised to conform to the new presentation. The impact to 2013, 2012 and 2011 was not material. Refer to Notes 1(c), 1(p) and 1(q) for further details.

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•	Executive Summary

•	Results of Operations

•	Strategic Overview

•	Rate Matters

•	Environmental Matters

•	Legislative Matters

•	Liquidity and Capital Resources

•	Other Matters

•	Market Risk Sensitive Instruments and Positions

•	New Accounting Standards

•	Critical Accounting Policies and Estimates

•	Other Future Considerations

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•

WPL’s Proposed Riverside Expansion - WPL filed a CPCN application with the PSCW for approval to construct the Riverside expansion, a natural gas-fired combined-cycle EGU in Beloit, Wisconsin. Capital expenditures, excluding AFUDC, are currently estimated to be approximately $700 million to construct the EGU and a pipeline to supply natural gas to the EGU. A decision from the PSCW on WPL’s application is currently expected by the second quarter of 2016. Refer to “Strategic Overview” for discussion of a settlement agreement WPL entered into with other Wisconsin utilities and certain electric cooperatives regarding its proposed Riverside expansion CPCN application.

•

Sales of IPL’s Minnesota Electric and Natural Gas Distribution Assets - In 2015, IPL completed the sales of its Minnesota electric and natural gas distribution assets and received proceeds of $140 million. The proceeds from the natural gas distribution assets were used for general corporate purposes and the proceeds from the electric distribution assets were used to reduce cash amounts received from IPL’s sales of accounts receivable program.

•

MISO Transmission Owner Return on Equity Complaints - Complaints are currently pending with FERC regarding the level of return on equity that MISO transmission owners, including ITC and ATC, should be allowed to utilize in calculating the rates they charge their customers. Alliant Energy, IPL and WPL currently anticipate FERC’s decision on the MISO transmission owner complaints will reduce transmission owners’ current return on equity, which is expected to result in lower electric transmission service expense billed to IPL and WPL thereby reducing customer costs, and lower equity income and dividends from ATC in the future. In 2014, FERC issued an order on the complaints establishing an effective refund date of November 12, 2013. Alliant Energy and WPL have realized $15 million of reductions in the amount of equity income from ATC for the period from November 12, 2013 through December 31, 2015, including $12 million realized in 2015 and $3 million realized in 2014.

•	At-the-Market Offering Program - In 2015, Alliant Energy issued 2,186,617 shares of common stock through an at-the-market offering program and received cash proceeds of $133 million, net of $2 million in fees and commissions. The proceeds from the issuances of common stock were used for general corporate purposes.

•	Customer Billing and Information System - Corporate Services placed in service a new customer billing and information system for IPL and WPL in 2015, which houses all customer records, and processes metering, billing and payment transactions.

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Protecting Americans from Tax Hikes Act - In December 2015, the PATH Act was enacted. The most significant provisions of the PATH Act for Alliant Energy, IPL and WPL relate to the extension of bonus depreciation deductions for certain capital expenditures for property incurred through December 31, 2019 and placed in service prior to December 31, 2020, as well as incentives for individuals and businesses to construct renewable generation. Refer to “Rate Matters” for further discussion.

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Clean Power Plan - In 2015, the EPA published final standards under Section 111(d) of the CAA, which establish guidelines for states to follow in developing plans to reduce CO2 emissions from existing fossil-fueled EGUs. In February 2016, the Supreme Court issued a stay of these final standards until pending legal challenges are resolved, which places implementation of these final standards on hold indefinitely. In 2015, the EPA also published final standards under Section 111(b) of the CAA, which establish CO2 emissions limits for certain new fossil-fueled EGUs. Refer to “Environmental Matters” for further discussion.

•

Planned Utility Rate Cases - WPL currently expects to make a retail electric and gas base rate filing for the 2017/2018 Test Period in the second quarter of 2016. WPL currently expects to make a retail fuel-related rate filing (2017 Test Year) in the second quarter of 2016. IPL currently expects to make separate retail electric and gas rate filings in the first half of 2017 based on a 2016 historical Test Year. Refer to “Rate Matters” for further discussion.

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Financing Plans - Alliant Energy currently expects to issue approximately $25 million of common stock in 2016 through its Shareowner Direct Plan. IPL and WPL currently expect to receive capital contributions of approximately $165 million and $25 million, respectively, from their parent company, Alliant Energy, in 2016. IPL currently expects to issue up to $300 million of long-term debt in 2016. The Alliant Energy parent company and Resources currently expect to issue up to approximately $400 million of long-term debt in aggregate, primarily to refinance Alliant Energy’s $250 million and Franklin County Holdings LLC’s $60 million variable-rate term loan credit agreements expiring in 2016.

•

Common Stock Dividends - Alliant Energy announced an increase in its targeted 2016 annual common stock dividend to $2.35 per share, which is equivalent to a quarterly rate of $0.5875 per share, beginning with the February 2016 dividend payment. The timing and amount of future dividends is subject to an approved dividend declaration from Alliant Energy’s Board of Directors, and is dependent upon earnings expectations, capital requirements, and general financial business conditions, among other factors. In addition, IPL and WPL currently expect to pay common stock dividends of approximately $150 million and $135 million, respectively, to their parent company in 2016.

•	Utility Electric Margins - Alliant Energy, IPL and WPL are currently expecting a modest increase in temperature-normalized retail electric sales in 2016 compared to 2015. IPL currently expects to reduce the amount of billing credits on its Iowa retail electric customers’ bills in 2016 compared to 2015 related to the approved settlement agreement for IPL’s Iowa retail electric rates.

•	Electric Transmission Service Expense - Alliant Energy currently expects an increase in future electric transmission service expense in 2016 compared to 2015 due to higher Attachment “O” rates charged by ITC and ATC, as well as higher MISO transmission charges billed to IPL and WPL due to the number of shared transmission projects expected to be completed in the MISO region.

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Other Operation and Maintenance Expenses - Alliant Energy and WPL currently expect decreases in energy efficiency cost recovery amortizations at WPL in 2016 compared to 2015 as approved by the PSCW in a July 2014 order. Partially offsetting this expected decrease, Alliant Energy, IPL and WPL currently expect an increase in retirement plan costs in 2016 compared to 2015, resulting from lower than expected returns on retirement plan assets in 2015.

•	Depreciation and Amortization Expenses - Alliant Energy currently expects its depreciation and amortization expenses to increase in 2016 compared to 2015 due to property additions, including various environmental controls projects at IPL and WPL placed in service in 2015 and expected to be placed in service in 2016.

•	Interest Expense - Alliant Energy currently expects its interest expense to increase in 2016 compared to 2015 due to financings in 2015 and 2016 discussed above.

•	AFUDC - Alliant Energy currently expects AFUDC to increase in 2016 compared to 2015 primarily due to increased CWIP balances related to Marshalltown.

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(a)	Reflects the % change from 2014 to 2015. (b) Reflects the % change from 2013 to 2014.

(c)

In July 2015, IPL sold its electric distribution assets in Minnesota to Southern Minnesota Energy Cooperative. Prior to the asset sale, the related electric sales are included in residential, commercial and industrial retail sales. Subsequent to the asset sale, the related electric sales are included in wholesale electric sales pursuant to a wholesale power supply agreement between IPL and Southern Minnesota Energy Cooperative.

(d)	Includes $72 million, $85 million and $79 million of credits on IPL’s Iowa retail electric customers’ bills for 2015, 2014 and 2013, respectively, resulting from the electric tax benefit rider. The electric tax benefit rider resulted in reductions in electric revenues that were offset by reductions in income tax expense for 2015, 2014 and 2013.

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(a)	Refer to Note 2 for further discussion of billing credits that began in 2014 related to the approved settlement agreement for IPL’s Iowa retail electric rates.

(b)	The PSCW order received for WPL’s retail fuel-related rate filing (2015 Test Year) contained an increase in retail electric fuel-related revenues in 2015. A portion of the approved increase was attributable to the impact of increased sales volumes approved in WPL’s retail electric base rate case for 2015 resulting in higher electric margin in 2015.

(c)	Includes increases in temperature-normalized retail sales volumes at WPL in 2015 and 2014. Refer to “Sales Trends” below for more information.

(d)	Higher transmission rider revenues were offset by higher electric transmission service expense.

(e)	Primarily due to lower nuclear capacity costs in 2014, which are included in the rates charged to wholesale customers.

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(a)	Reflects the % change from 2014 to 2015. (b) Reflects the % change from 2013 to 2014.

(c)	Includes $12 million, $12 million and $11 million of credits on IPL’s Iowa retail gas customers’ bills for 2015, 2014 and 2013, respectively, resulting from the gas tax benefit rider. The gas tax benefit rider resulted in reductions in gas revenues that were offset by reductions in income tax expense for 2015, 2014 and 2013.

(a)	Changes in energy efficiency revenues were mostly offset by changes in energy efficiency expense included in other operation and maintenance expenses.

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(a)

Approximately 50% of all margins earned from IPL’s sharing mechanism relating to optimizing gas capacity contracts flow through the purchased gas adjustment clause to reduce retail gas customer bills in Iowa. The remaining margins are retained by IPL and recorded in utility other revenues. Due to the extreme cold temperatures causing natural gas price fluctuations in the first quarter of 2014, margins were higher than normal in 2014.

(b)	Changes in utility other revenues related to coal sales were largely offset by changes in utility other operation and maintenance expenses related to coal sales.

(a)	Primarily due to increased electric transmission service rates.

(b)

IPL is currently recovering the Iowa retail portion of its increased electric transmission service costs from its retail electric customers in Iowa through a transmission cost rider approved by the IUB in January 2011 and extended as part of the rate settlement approved in September 2014. The difference between electric transmission services expense and amounts collected from customers as electric revenues results in temporary costs (credits) recorded in electric transmission service expense until the amounts are reflected in future customer billings.

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(a)

The July 2014 PSCW order for WPL’s 2015/2016 Test Period electric and gas base rate case authorized lower energy efficiency cost recovery amortizations for 2015. The July 2012 PSCW order for WPL’s 2013/2014 Test Period electric and gas base rate case authorized changes in energy efficiency cost recovery amortizations for 2013 and 2014. Regulatory amortizations at WPL related to energy efficiency costs were $4 million, $42 million and $22 million in 2015, 2014 and 2013, respectively.

(b)	Primarily due to the timing and extent of maintenance projects at IPL’s and WPL’s EGUs.

(c)	Changes in IPL’s energy efficiency expense were offset by changes in electric and gas energy efficiency revenues.

(d)	Primarily due to an increase in retirement plans costs and other employee benefits-related costs. The increased retirement plan costs were largely due to decreases in discount rates and a change to life expectancy assumptions in 2014.

(e)	In 2013, IPL received an order from the MPUC approving full cost recovery of the Minnesota retail portion of IPL’s Whispering Willow - East wind farm construction costs effective January 1, 2013. As a result, Alliant Energy and IPL reversed a prior reserve and recognized a $7 million regulatory-related credit in 2013.

(f)	Primarily due to increased customer billing and customer assistance-related expenses.

(g)	Primarily due to a decrease in retirement plan costs, partially offset by an increase in other employee benefits-related costs and the reversal of a previously recorded reserve related to the Cash Balance Plan in 2013.

(h)	Changes in expense related to coal sales at WPL were largely offset by changes in coal sales revenue at WPL.

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•	Natural gas - purchasing, constructing and/or converting to natural gas-fired EGUs.

•	Renewables - operating wind farms and hydroelectric generators, as well as evaluating the development of future wind sites and solar projects.

•	Coal - implementing environmental controls and generation performance and reliability improvements at newer, larger and more efficient coal-fired EGUs, and fuel switching at, and retirement of, certain older, smaller and less efficient coal-fired EGUs.

•	PPAs - purchasing electricity to meet a portion of customers’ demand for electricity, including wind and solar power PPAs and a nuclear generation PPA related to DAEC for a term of February 2014 through December 2025.

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•	A cost cap of $920 million, including costs to construct Marshalltown, a pipeline to supply natural gas to Marshalltown and transmission network upgrades to transmit electricity from Marshalltown, as well as AFUDC. Any costs incurred in excess of the cost cap are expected to be incorporated into rates if determined to be reasonable and prudent.

•	An 11% return on common equity for the 35-year depreciable life of Marshalltown and a 10.3% return on common equity for the calculation of AFUDC related to the construction of Marshalltown.

•	The application of double leverage is deferred until IPL’s next retail electric base rate case or other proceeding.

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(a)	Assumes an in-service date in early 2020.

•	Riverside Expansion Market Participation Date - WPL agreed that the proposed Riverside expansion would not enter the MISO capacity market prior to the date set by MISO for qualifying generation as a capacity asset for the MISO planning year beginning June 1, 2020.

•	Riverside Expansion Interconnection Study - WPL agreed to file a request with MISO on behalf of itself, Wisconsin Electric and WPSC to complete a non-binding study to assess an interconnection option of the proposed Riverside expansion to ATC’s transmission system. WPL and the parties filed such request with MISO in January 2016.

•	WPL and Wisconsin Electric PPA - WPL and Wisconsin Electric agreed to enter into a PPA whereby WPL would purchase specified levels of energy and capacity from Wisconsin Electric through 2019.

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Renewable Generation Joint Development Agreement - WPL, Wisconsin Electric and WPSC agreed to negotiate a separate joint development agreement for the purpose of cooperatively developing any renewable resources greater than 50 MW in Wisconsin for the benefit of their respective customers. The terms of such agreement would be 10 years beginning on a date no later than June 1, 2016. The utility that originates such renewable resource would hold a majority ownership and operational control of the renewable resource. The other two utilities would have the right to acquire a minority interest in the other utility’s renewable resource.

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(a)	Scrubber is a post-combustion process that injects lime or lime slurry into the stream of gases leaving the EGU boiler to remove SO2 and other acid gases (including hydrochloric acid) and capture them in a solid or liquid waste by-product. A scrubber typically removes more than 90% of the SO2 emissions.

(b)

IPL’s Environmental Controls Projects - Under Iowa law, IPL is required to file an EPB biennially. Filing of periodic reports regarding the implementation of IPL’s compliance plan and related budget identified in an EPB is also currently required under a settlement agreement between IPL and the Iowa Office of Consumer Advocate. An EPB provides a utility’s compliance plan and related budget for managing regulated emissions from its coal-fired EGUs in a cost-effective manner. IUB approval of an EPB demonstrates that the EPB is reasonably expected to achieve cost-effective compliance with applicable state environmental requirements. IPL plans to include the SCR for Ottumwa Unit 1 in its next EPB filing, which is currently expected to be filed with the IUB in the first quarter of 2016.

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(a)	These actions and plans meet requirements specified in the Consent Decrees, which are discussed in Note 16(e).

(b)

Final MISO studies could indicate that the retirement of an individual EGU may result in reliability issues and that transmission network upgrades for system reliability are necessary to enable such retirement. Under the current MISO tariff, the specific timing for the retirement of these EGUs could depend on the timing of the required transmission network upgrades as well as various operational, market and other factors.

(c)	The retirements of Fox Lake Unit 3, Sutherland Units 1 and 3, and other units are contingent on the construction of Marshalltown as well as various operational, market and other factors.

(d)	Reflects WPL’s 68.2% ownership interest in Edgewater Unit 4.

(e)	The retirements of Edgewater Unit 4 and the Rock River and Sheepskin Combustion Turbine Units are contingent on the construction of the Riverside expansion as well as various operational, market and other factors.

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(a)	Authorized returns on common equity may not be indicative of actual returns earned or projections of future returns.

(b)	Authorized returns on common equity and after-tax WACC reflect application of double leverage pursuant to a January 2011 IUB order. Prior to the application of double leverage, authorized returns on common equity were: Emery-12.23%, Whispering Willow-East-11.7% and Other-10.0%, and after-tax WACC were: Emery-9.16%, Whispering Willow-East-8.91% and Other-8.09%.

(c)	Average rate base was calculated using a 13-month average during the test year adjusted for post-test year capital additions placed in service by September 30 following the end of the test year.

(d)	Authorized returns on common equity and after-tax WACC reflect application of double leverage pursuant to the unanimous settlement agreement approved in the IUB’s November 2012 order. Prior to the application of double leverage, authorized return on common equity was 10.0% and after-tax WACC was 8.0%.

(e)	IPL’s wholesale formula rates reflect annual changes in CE, PE, LD, WACC and rate base.

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(f)	Wholesale average rate base reflects production-related rate base calculated as the simple average of the beginning of the test year and end of the test year balances in accordance with the respectively approved formula rates.

(g)	Average rate base amounts do not include CWIP or a cash working capital allowance and were calculated using a forecasted 13-month average for the test period. The PSCW provides a return on selected CWIP and a cash working capital allowance by adjusting the percentage return on rate base.

(h)	WPL’s wholesale formula rates reflect annual changes in WACC and rate base.

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(a)	IPL’s M.L. Kapp Unit 2 fuel type was switched from coal to natural gas in 2015.

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(a)	CO2e emissions reported to the EPA represent all emissions from the facilities operated by IPL and WPL and do not reflect their share of co-owned facilities operated by other companies.

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(a)	Largely due to higher expenditures for Marshalltown and environmental controls projects at WPL’s Edgewater Unit 5 in 2015, partially offset by lower expenditures for environmental controls projects at IPL’s Ottumwa Unit 1 and WPL’s Columbia Units 1 and 2 in 2015.

(a)	Largely due to higher expenditures for Marshalltown, IPL’s and WPL’s electric and gas distribution systems and environmental controls projects at WPL’s Edgewater Unit 5 in 2014, partially offset by lower expenditures for environmental controls projects at WPL’s Columbia Units 1 and 2 in 2014.

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(a)

Purchased power and fuel commitments represent normal business contracts used to ensure adequate purchased power, coal and natural gas supplies, and to minimize exposure to market price fluctuations. Alliant Energy, through its subsidiary Corporate Services, entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of December 31, 2015 regarding expected future usage, which is subject to change.

(b)	Other operating expense purchase obligations represent individual commitments incurred during the normal course of business that exceeded $1 million at December 31, 2015.

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(a)	In 2013, the IUB issued an order establishing rate-making principles for Marshalltown that requires a 10.3% return on common equity for the calculation of AFUDC related to the construction of such facility.

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(a)	In December 2015, WPL retired Nelson Dewey Units 1 and 2 and Edgewater Unit 3 and transferred the remaining net book value from property, plant and equipment to regulatory assets pursuant to orders from the PSCW and FERC. Refer to Note 2 for discussion of the recovery of the remaining net book value of these EGUs.

(b)	Less accumulated amortization of $65.2 million and $59.1 million for WPL as of December 31, 2015 and 2014, respectively.

(c)	Less accumulated depreciation of $59.0 million and $49.5 million for Alliant Energy as of December 31, 2015 and 2014, respectively.

(d)	Less accumulated depreciation of $252.9 million and $229.1 million for Alliant Energy as of December 31, 2015 and 2014, respectively.

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(a)	Changes in cash proceeds are presented in “Sales of accounts receivable” in operating activities in Alliant Energy’s and IPL’s cash flows statements.

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(a)	Alliant Energy and WPL have the ability to exercise significant influence over ATC’s financial and operating policies through their participation on ATC’s Board of Directors. Refer to Note 18 for information regarding related party transactions with ATC.

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(a)	In 2015, IPL issued $250.0 million of 3.4% senior debentures due 2025. The proceeds from the issuance were used by IPL to reduce commercial paper classified as long-term debt by $111 million, reduce cash amounts received from its sales of accounts receivable program and for general corporate purposes.

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(a)	These federal tax returns are effectively settled as a result of participation in the IRS Compliance Assurance Program, which allows Alliant Energy and the IRS to work together to resolve issues related to Alliant Energy’s current tax year before filing its federal income tax return. The statute of limitations for these federal tax returns expires three years from each filing date.

(b)	The statute of limitations for these Iowa tax returns expires three years from each filing date.

(c)	The statute of limitations for these Wisconsin combined tax returns expires four years from each filing date.

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(a)	The expected return on plan assets is based on the expected rate of return on plan assets and the fair value approach to the market-related value of plan assets.

(b)	Unrecognized prior service costs (credits) for the OPEB plans are amortized over the average future service period to full eligibility of the participants of each plan.

(c)	Unrecognized net actuarial gains or losses in excess of 10% of the greater of the plans’ benefit obligations or assets are amortized over the average future service lives of plan participants, except for the Cash Balance Plan where gains or losses outside the 10% threshold are amortized over the time period the participants are expected to receive benefits.

(d)

In 2013, Alliant Energy filed a stipulation agreement with the Western Wisconsin Court related to a class-action lawsuit against the Cash Balance Plan. As a result, Alliant Energy recognized $9.0 million of additional benefits costs in 2013 related to the agreement. IPL recognized $5.5 million ($2.6 million directly assigned and $2.9 million allocated by Corporate Services) and WPL recognized $2.8 million ($0.6 million directly assigned and $2.2 million allocated by Corporate Services) of additional benefits costs in 2013 related to the agreement.

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(a)	Refer to Note 2 and Alliant Energy’s common equity statements for amounts recognized in “Regulatory assets” and “AOCL,” respectively, on Alliant Energy’s balance sheets.

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(a)	Refer to Note 2 for amounts recognized in “Regulatory assets” on IPL’s balance sheets.

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(a)	Refer to Note 2 for amounts recognized in “Regulatory assets” on WPL’s balance sheets.

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(a)

Alliant Energy sponsors several non-qualified defined benefit pension plans that cover certain current and former key employees of IPL and WPL. Alliant Energy allocates pension costs to IPL and WPL for these plans. In addition, IPL and WPL amounts reflect funding for their non-bargaining employees who are participants in the Alliant Energy and Corporate Services sponsored qualified and non-qualified defined benefit pension plans.

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(a)	In 2015, 49,093 performance-contingent restricted shares granted in 2013 vested because the specified performance criteria for such shares were met. In 2014, 45,612 and 45,235 performance-contingent restricted shares granted in 2012 and 2011, respectively, vested because the specified performance criteria for such shares were met.

(b)	In 2013, 101,822 performance-contingent restricted shares granted in 2009 were forfeited because the specified performance criteria for such shares were not met. The forfeitures during 2014 were primarily caused by retirements and terminations of participants.

(a)	In 2015, 37,332 performance-contingent cash awards granted in 2013 vested, resulting in cash payouts valued at $2.4 million. In 2014, 34,766 and 20,751 performance-contingent cash awards granted in 2012 and 2011 vested, resulting in cash payouts valued at $1.9 million and $1.1 million, respectively.

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(a)

In April 2015, the EPA published the final CCR Rule, which regulates CCR as a non-hazardous waste and is effective October 2015. IPL and WPL have nine and three coal-fired EGUs, respectively, with coal ash ponds that are impacted by this rule. In addition, IPL and WPL have four and two active CCR landfills, respectively, that are impacted by this rule. In 2015, Alliant Energy, IPL and WPL recognized additional AROs of $87 million, $67 million and $20 million, respectively, as a result of the final CCR Rule. The increases in AROs resulted in corresponding increases in “Property, plant and equipment, net” on the respective balance sheets. Actual costs resulting from the CCR rule may be different than the amounts recorded in 2015 due to potential changes in compliance strategies that will be used, as well as other potential cost estimate changes. Expenditures incurred by IPL and WPL to comply with the CCR Rule are anticipated to be recovered in rates from their customers.

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(a)	Settlements related to deferred proceeds are due to the change in the carrying amount of receivables sold less the allowance for doubtful accounts associated with the receivables sold and cash amounts received from the receivables sold.

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(a)	Includes payments required by PPAs for capacity rights and minimum quantities of MWhs required to be purchased. Refer to Note 18 for additional information on purchased power transactions.

(b)	Includes commitments incurred under a PPA, which grants IPL rights to purchase up to 431 MWs of capacity and the resulting energy from DAEC for a term through December 31, 2025. If energy delivered is less than the targeted energy amount, an adjustment payment will be made to IPL, which will be reflected in IPL’s fuel adjustment clause.

(c)	Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments. These commitments were assigned to IPL and WPL based on information available as of December 31, 2015 regarding expected future usage, which is subject to change.

(d)	Includes individual commitments incurred during the normal course of business that exceeded $1 million at December 31, 2015.

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•	SCR system at Edgewater Unit 5 by May 1, 2013 (placed in service in 2012);

•	Scrubbers and baghouses at Columbia Units 1 and 2 by December 31, 2014 (placed in service in 2014);

•	Scrubber and baghouse at Edgewater Unit 5 by December 31, 2016; and

•	SCR system at Columbia Unit 2 by December 31, 2018.

•	Scrubber and baghouse at the Ottumwa Generating Station by December 31, 2015 (placed in service in 2014);

•	Scrubber and baghouse at the Lansing Generating Station by December 31, 2016 (scrubber was placed in service in June 2015 and baghouse was placed in service in 2010); and

•	SCR system or equivalent NOx reduction system at the Ottumwa Generating Station by December 31, 2019.

•	M.L. Kapp Generating Station by August 31, 2015 (switched the fuel type from coal to natural gas in June 2015);

•	Prairie Creek Unit 4 by June 1, 2018;

•	Burlington Generating Station by December 31, 2021; and

•	Prairie Creek Units 1 and 3 by December 31, 2025.

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•

Utility - includes the operations of IPL and WPL, which primarily serve retail customers in Iowa and Wisconsin. The utility business has three reportable segments: a) utility electric operations; b) utility gas operations; and c) utility other, which includes steam operations and the unallocated portions of the utility business. Various line items in the following tables are not allocated to the electric and gas segments for management reporting purposes, and therefore, are included only in “Total Utility.”

•	Non-regulated, Parent and Other - includes the operations of Resources and its subsidiaries, Corporate Services, the Alliant Energy parent company, and any Alliant Energy parent company consolidating adjustments. Resources’ businesses include Transportation, Non-regulated Generation and other non-regulated investments described in Note 1(a).

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(a)

Represents performance shares granted under the OIP. The performance shares may be paid out in shares of Alliant Energy’s common stock, cash, or a combination of cash and stock and are adjusted by a performance multiplier, which ranges from zero to 200%, based on the performance criteria. The performance shares included in column (A) of the table reflect an assumed payout in the form of Alliant Energy’s common stock at the maximum performance multiplier of 200% for the 2015 and 2014 grants and at the actual performance multiplier of 165% for the 2013 grants.

(b)

All of the available shares under the Amended and Restated OIP may be issued as awards in the form of shares of Alliant Energy’s common stock, restricted stock, restricted stock units, performance shares, performance units and other stock-based or cash-based awards. As of December 31, 2015, there were performance shares and restricted stock awards outstanding under the Amended and Restated OIP. Excludes 95,122 shares of non-vested restricted common stock previously issued and outstanding under the Amended and Restated OIP at December 31, 2015.

(c)	As of December 31, 2015, there were 215,093 shares of Alliant Energy’s common stock outstanding under the DCP, which is described in Note 12(c).

(d)	There is no limit on the number of shares of Alliant Energy’s common stock that may be held under the DCP.

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(1)	Consolidated Financial Statements - Refer to Item 8 Financial Statements and Supplementary Data.

(2)	Financial Statement Schedules -

(3)	Exhibits Required by SEC Regulation S-K - Exhibits for Alliant Energy, IPL and WPL are listed in the Exhibit Index, which is incorporated herein by reference.

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(a)	Accumulated provision for uncollectible accounts: In accordance with its regulatory treatment, certain amounts provided by WPL are recorded in regulatory assets.

(b)	Deductions are of the nature for which the reserves were created. In the case of the accumulated provision for uncollectible accounts, deductions from this reserve are reduced by recoveries of amounts previously written off.

(c)	Refer to Note 5(b) for discussion of IPL’s sales of accounts receivable program.

(d)	Other reserves are largely related to injury and damage claims arising in the ordinary course of business.

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