MGIC INVESTMENT CORP

On May 4, 2026, Timothy J. Mattke, Chief Executive Officer, adopted a written plan for the sale of MGIC common stock that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act. Mr. Mattke’s written plan provides for the sale of 619,784 shares of MGIC common stock in the aggregate. This written plan is scheduled to expire on the earlier of: (1)June 4, 2027; or (2) the date on which an aggregate of 619,784 shares of MGIC common stock have been sold.

The information set forth below is included for the purpose of providing disclosure under Item 5.03 Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year.

On July 23, 2026, the Board of Directors approved amendments to the Amended and Restated Bylaws of the Company. Below is a brief description of the substantive amendments.

•Section 2.14 was amended to provide that, to be timely, a shareholder’s notice of nominations or a proposal of business to be conducted at an annual meeting of shareholders must be received by the Secretary of the Company not less than 90 days nor more than 120 days prior to the first annual anniversary of the immediately preceding annual meeting. Prior to the amendment, the period for such notice was not less than 80 days nor more than 105 days prior to the first annual anniversary of the immediately preceding annual meeting.

•Section 2.14 was also amended so that in the event that the date for which the annual meeting of shareholders is called is advanced by more than 30 days or delayed by more than 30 days from the first annual anniversary of the immediately preceding annual meeting, notice by the shareholder to be timely must be so delivered not earlier than the 120th day prior to the date of such annual meeting and not later than the later of (A) the 90th day prior to the date of such annual meeting and (B) the seventh day following the day on which public announcement of the date of such annual meeting is first made.

•Section 2.14 was amended to require shareholders and beneficial owners to provide additional information to the Company in connection with their nominations or proposals of other business and require that such information also be provided by any other participants involved in the solicitation of proxies, in addition to shareholders and beneficial owners.

•Section 2.14 was amended to require each director nominee to provide to the Company in connection with his or her nomination, additional information about the nominee and a written representation and agreement that the nominee will not enter into an agreement or understanding that provides for a voting commitment in connection with the nominees service as a director.

These amendments are effective July 23, 2026. The foregoing description is qualified in its entirety by reference to the actual text of the amendments.