LNTNasdaq

ALLIANT ENERGY CORP

Electric & Other Services Combined · WI · CIK 352541

Alliant Energy provides regulated electric and natural gas service and manages non-utility holdings

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$18.88B

Market cap

$77.18

Last close

-0.1%

+5.4%

2.4M

Volume

Price · last 39 sessions+4.8%

May 4L $69.57 · H $77.25Jun 29

256

Total filings

Jun 16, 2026

Last filing

12/31

Fiscal year end

All 8-K · 155 10-Q · 38 DEF 14A · 13 11-K · 13 10-K · 13 424B5 · 10 DEFA14A · 9 SC 13G · 5

What Changed

Risk factors · Feb 21, 2025 → Feb 20, 2026

52 added · 53 removed between the two most recent 10-Ks. The risks a company starts — or stops — disclosing are often the story.

Newly disclosed

Community opposition to data centers—driven by concerns about land use, water consumption, generation emissions, noise, or traffic—could result in permitting delays, litigation, project cancellations, or additional mitigation costs, reducing expected load growth.
IPL also sells electricity to wholesale customers in Illinois and Iowa and was engaged in the generation and distribution of steam for two customers in Cedar Rapids, Iowa, which were each under contract through 2025 for taking minimum quantities of annual steam usage, with certain conditions.
Subsequent to December 31, 2025, IPL exited the steam business. 2) WPL - is a public utility engaged principally in the generation and distribution of electricity and the distribution and transportation of natural gas to retail customers in select markets in Wisconsin.
The Inflation Reduction Act and related guidance also include limitations on the use of components and/or financing from entities with ties to certain foreign countries.
In February 2026, the EPA finalized a rule to rescind its 2009 finding that GHG contributes to climate change, concluding that regulation of GHG falls outside of the scope of the CAA.
Alliant Energy, IPL and WPL expect to be able to comply with the updated NSPS requirements and will continue to monitor potential litigation.
In December 2025, EPA finalized an extended timeframe for the new requirements, which must now be implemented no later than December 31, 2034.
At December 31, 2025, WPL supplied electric and natural gas service to approximately 505,000 and 205,000 retail customers, respectively.
In June 2025, the EPA proposed to repeal the May 2024 111(b) revised standards and a final rule is expected in the first half of 2026.
In January 2026, EPA finalized updates to the NSPS for combustion turbines built, reconstructed, or modified after December 13, 2024.
Public Benefits - WPL contributes 1.2% of its annual retail utility revenues to help fund Focus on Energy, Wisconsin’s state-wide energy efficiency and renewable energy resource program.
Award recipients have achieved excellent records in high school, are pursuing a higher education, and may enroll in any accredited two- or four-year college, university or vocational-technical school in the U.S. 5 Table of Contents Employee Engagement - A workplace where everyone feels meaningful connection to work and company goals is crucial for the success and retention of our employees, to attract future talent and to execute our purpose-driven strategy to serve our customers and build stronger communities.

No longer disclosed

These risks could cause significant harm to employees, customers and the public, including loss of human life, significant damage to property, adverse impacts on the environment and impairment of our operations, all of which could result in substantial financial losses to us.
IPL is also engaged in the generation and distribution of steam for two customers in Cedar Rapids, Iowa, which are each under contract through 2025 for taking minimum quantities of annual steam usage, with certain conditions, after which IPL expects to exit the steam business. 2) WPL - is a public utility engaged principally in the generation and distribution of electricity and the distribution and transportation of natural gas to retail customers in select markets in Wisconsin.
If WPL’s coal-fired Columbia Energy Center is retired by the end of 2029, the final rule would not be applicable; however, if WPL converts Columbia Unit 1 and/or Unit 2 to natural gas, then the final rule would be applicable for the EGUs that are converted.
In 2023, the EPA finalized revisions to the CSAPR state-specific ozone season nitrogen oxides emission caps and utility-specific emission allowances for certain states, including Wisconsin, beginning in 2023; however, these revisions were stayed by the Supreme Court in June 2024.
In December 2024, the EPA proposed updates to the NSPS for combustion turbines built, reconstructed, or modified after December 13, 2024, which would establish more stringent emission limits for nitrogen oxides emissions and retain the current sulfur dioxide emission limits.
In November 2024, the EPA issued an interim final rule to stay the 2023 rule and re-establish the prior emission caps and allowance allocations, including Wisconsin, pending judicial review.
The new limitations will be implemented in each facility’s wastewater discharge permits issued by state agencies and become effective as soon as possible but no later than December 31, 2029.
Currently, WPL is required to defer a portion of its earnings if its annual regulatory return on common equity exceeds certain levels. 7 Table of C o ntents Public Benefits - WPL contributes 1.2% of its annual retail utility revenues to help fund Focus on Energy, Wisconsin’s state-wide energy efficiency and renewable energy resource program.
In addition, the final rule does not impact existing natural gas-fired combustion turbines, including IPL’s Marshalltown Generating Station and Emery Generating Station, and WPL’s Riverside Energy Center and West Riverside Energy Center; however, these EGUs could be subject to future Section 111(d) rules to reduce CO2 emissions from existing combustion turbines.
For example, WPL has notified the PSCW that its solar generating facility developments have exceeded the approved costs.
IPL also sells electricity to wholesale customers in Minnesota (IPL’s related wholesale power agreement expires July 2025), Illinois and Iowa.
At December 31, 2024, WPL supplied electric and natural gas service to approximately 500,000 and 200,000 retail customers, respectively.

In the News

Coverage (30d): 3 reputable articles.

MarketWatchAlliant Energy Corp. stock outperforms competitors despite losses on the day21d ago MarketWatchAlliant Energy Corp. stock outperforms competitors on strong trading day27d ago MorningstarThe Best Utilities Stocks to Buy29d ago

Reputable outlets only (Reuters, WSJ, CNBC, Barron's, and peers). More on Google News ↗

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