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Exhibit 99.1 News Release FOR IMMEDIATE RELEASE Alliant EnergyM Alliant Energy Corporation Corporate Headquarters 4902 North Biltmore Lane Madison , WI 53718-2148 www.alliantenergy.com Media Hotline : Investor Relations : ( 608 ) 458-4040 Zac Fields ( 319 ) 786-8146 ALLIANT ENERGY ANNOUNCES THIRD QUARTER 2021 RESULTS • Third quarter GAAP earnings per share was $ 1.02 in 2021 compared to $ 0.98 in 2020 • With strong year - to - date results , increased and narrowed 2021 earnings guidance range to $ 2.61 - $ 2.67 Provided 2022 earnings guidance range of $ 2.65 - $ 2.79 and 2022 annual common stock dividend target of $ 1.71 Increased forecasted 2021-2025 net capital expenditures to $ 7 billion in aggregate MADISON , Wis . - November 4 , 2021 - Alliant Energy Corporation ( NASDAQ : LNT ) today announced U.S. generally accepted accounting principles ( GAAP ) and non - GAAP consolidated unaudited earnings per share ( EPS ) for the three months ended September 30 as follows : Utilities and Corporate Services American Transmission Company ( ATC ) Holdings Non - utility and Parent Alliant Energy Consolidated GAAP EPS Non - GAAP EPS 2021 2020 2021 2020 $ 1.01 $ 0.89 $ 1.01 $ 0.89 0.03 0.03 0.03 0.03 ( 0.02 ) 0.06 ( 0.02 ) 0.02 $ 1.02 $ 0.98 $ 1.02 $ 0.94 " We are excited to deliver another quarter of consistent results , including several highlights such as being recognized for the third year in a row as a Top Utility in Economic Development by Site Selection magazine , ” said John Larsen , Alliant Energy Chair , President and CEO . " We narrowed and raised our 2021 earnings guidance to a range of $ 2.61 - $ 2.67 per share . I am also pleased to share that our Board of Directors has approved a 6 % increase in our annual common stock dividend target , raising it to $ 1.71 per share for 2022. " Utilities and Corporate Services - Alliant Energy's Utilities and Alliant Energy Corporate Services , Inc. ( Corporate Services ) operations generated $ 1.01 per share of GAAP EPS in the third quarter of 2021 , which was $ 0.12 per share higher than the third quarter of 2020. The primary drivers of higher EPS were higher earnings resulting from IPL's and WPL's increasing rate base , as well as higher sales due in part to the derecho windstorm in Iowa and COVID - 19 sales impacts in the third quarter of 2020. These items were partially offset by higher depreciation expense and lower allowance for funds used during construction ( AFUDC ) . Non - utility and Parent - Alliant Energy's Non - utility and Parent operations generated ( $ 0.02 ) per share of GAAP EPS in the third quarter of 2021 , which was an $ 0.08 per share earnings decrease compared to the third quarter of 2020. The lower EPS was primarily driven by an adjustment in 2020 to the credit loss liability related to legacy guarantees associated with an affiliate of Whiting Petroleum Corporation ( Whiting Petroleum ) and timing of income taxes . Earnings Adjustments - Non - GAAP EPS for the three months ended September 30 , 2020 excludes $ 0.04 per share related to the credit loss adjustment described above for Alliant Energy's Non - utility and Parent . Non - GAAP adjustments , which relate to material charges or income that are not normally associated with ongoing operations , are provided as a supplement to results reported in accordance with GAAP . Estimated Temperature Impacts to Non - GAAP EPS - The estimated year - to - date impact of temperatures on EPS compared to normal temperatures , is an $ 0.08 per share gain in 2021. The midpoint of the temperature normalized non - GAAP EPS guidance for the full year 2021 is $ 2.57 . 1