MGE ENERGY INC

Voting Matters

This summary highlights certain information contained elsewhere in the Proxy Statement for the 2025 Annual Meeting of MGE Energy. This summary does not contain all of the information you should consider and you should read the entire Proxy Statement and our 2024 Annual Report on Form 10-K before casting your vote.

How To Vote

Question: How can I attend the Annual Meeting?

The Annual Meeting will be held online. Shareholders are encouraged to participate by visiting the following website: www.virtualshareholdermeeting.com/mgee2025. To fully participate in the meeting, you will need your 16-digit control number from your proxy materials. See the Notice of Annual Meeting Shareholders at the beginning of this Proxy Statement for more information.

Question: How do I participate in the Annual Meeting?

Shareholders will be able to join via a webcast. An audio broadcast of the Annual Meeting also will be available by telephone

toll-free at 1-877-328-2502. Shareholders of record as of close of business on March 21, 2025, are entitled to participate in and to submit questions during the Annual Meeting by visitingwww.virtualshareholdermeeting.com/mgee2025.

To participate in the online Annual Meeting, you will need the 16-digit control number included on your proxy materials. The Annual Meeting will begin promptly at 11:00 a.m., Central Time (CT). Online check-in will begin at 10:30 a.m. CT. Please allow yourself time to log in to the virtual meeting.

Question: Why is it important to vote?

Your broker is not permitted to vote on your behalf on the election of directors or the advisory vote related to executive compensation matters. Thus, your broker needs your instructions in order for your shares to be voted on these matters. For your vote to be counted, you must communicate your voting instructions to your broker, bank or other financial institution before the date of the Annual Meeting. If you do not vote, your shares may not be represented at the Annual Meeting.