Form 8-K Filing Regarding Merger Agreement

Safety Insurance Group, Inc. announced that the waiting period under the HSR Act for its merger with MAPFRE U.S.A. Corp. and Splash Merger Sub, Inc. expired on September 14, 2026. This satisfies one of the conditions for closing the merger, although other regulatory approvals are still required. The company has filed a definitive proxy statement with the SEC, which was mailed to stockholders on September 14, 2026. Safety Insurance Group urges stockholders to read the proxy statement and other relevant SEC filings for important information regarding the proposed transaction. The report also includes cautionary statements regarding forward-looking statements and potential risks associated with the merger.