Exhibit 99.1 CMS Energy Announces First Quarter Results for 2024, Reaffirms 2024 Adjusted EPS Guidance JACKSON, Mich., April 25, 2024 – CMS Energy announced today reported earnings per share of $0.96 for the first quarter of 2024, compared to$0.69 per share for 2023. The company’s adjusted earnings per share for the first quarter were $0.97, compared to$0.70 per share for 2023 primarily due to higher weather-normalized sales and lower storm restoration costs. CMS Energy reaffirmed its 2024 adjusted earnin ...