Form 8-K

8-K — SAFETY INSURANCE GROUP INC

Accession: 0001104659-26-107960

Filed: 2026-09-15

Period: 2026-09-14

CIK: 0001172052

SIC: 6331 (FIRE, MARINE & CASUALTY INSURANCE)

Item: Other Events

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES

EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported):

September 14, 2026

SAFETY INSURANCE GROUP, INC.

(Exact Name of Registrant as Specified in Charter)

Delaware

000-50070

13-4181699

(State or Other Jurisdiction

of Incorporation)

(Commission File Number)

(IRS Employer

Identification No.)

20 Custom House Street, Boston, Massachusetts

02110

(Address of Principal Executive Offices)

(Zip Code)

Registrant’s telephone number, including area code: (617) 951-0600

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation

of the registrant under any of the following provisions:

Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b)

of the Act:

Title of each class

Trading symbol(s)

Name of each exchange on which registered

Common Stock, $0.01 par value per share

SAFT

The NASDAQ Stock Market LLC

Indicate by check mark whether the registrant

is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 or Rule 12b-2 of the Securities Exchange Act of 1934.

Emerging growth company ¨

If an emerging growth company, indicate by check

mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting

standards provided pursuant to Section 13(a) of the Securities Exchange Act of 1934. ¨

Item 8.01.

Other Events.

As previously announced,

on July 23, 2026, Safety Insurance Group, Inc., a Delaware corporation (“Safety”), entered into an Agreement

and Plan of Merger (as it may be amended, supplemented or modified from time to time, the “Merger Agreement”)

with MAPFRE U.S.A. Corp., a Massachusetts corporation (“Mapfre”), and Splash Merger Sub, Inc., a Delaware corporation

and wholly owned direct subsidiary of Mapfre (“Merger Subsidiary”), pursuant to which Merger Subsidiary will

be merged with and into Safety (the “Merger”), with Safety surviving the Merger as a wholly owned direct subsidiary

of Mapfre.

The consummation of the

Merger (the “Closing”) is subject to certain customary conditions, including the expiration or termination of

the required waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended (the “HSR Act”).

The waiting period under the HSR Act with respect to the Merger expired at 11:59 p.m. Eastern Time on September 14, 2026, satisfying one

of the conditions to Closing.

The Closing remains subject

to other customary conditions, including the receipt of certain other regulatory approvals.

Additional Information and Where to Find It

This communication is

being made in respect of the proposed Merger involving Safety, Mapfre and Merger Subsidiary. Safety filed a definitive proxy statement

with the Securities and Exchange Commission (the “SEC”). The definitive proxy statement was first mailed to

Safety’s stockholders on or about September 14, 2026. Safety may also file other relevant documents with the SEC regarding the proposed

transaction and related matters. This Current Report on Form 8-K is not a substitute for the definitive proxy statement or any other document

that Safety may file with the SEC. STOCKHOLDERS OF SAFETY ARE URGED TO READ THE DEFINTIVE PROXY STATEMENT (INCLUDING ANY AMENDMENTS OR

SUPPLEMENTS THERETO AND ANY DOCUMENTS INCORPORATED BY REFERENCE THEREIN) AND OTHER RELEVANT DOCUMENTS IN CONNECTION WITH THE PROPOSED

TRANSACTION THAT HAVE BEEN (OR WILL BE) FILED WITH THE SEC WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION

ABOUT THE PROPOSED TRANSACTION AND THE PARTIES TO THE PROPOSED TRANSACTION. Stockholders and investors will be able to obtain free copies

of the definitive proxy statement and other relevant materials (when available) and other documents filed by Safety at the SEC’s

website at www.sec.gov. Copies of the definitive proxy statement and the filings that will be incorporated by reference therein may also

be obtained, without charge, by contacting Safety’s Investor Relations at investorrelations@safetyinsurance.com or (877) 951-2522.

Participants in the Solicitation

Safety, Mapfre and their respective directors

and executive officers may be deemed, under SEC rules, to be participants in the solicitation of proxies in respect of the proposed transaction.

Information regarding Safety’s directors and executive officers is available in (a) Safety’s Annual Report on Form 10-K for

the fiscal year ended December 31, 2025, including under the headings “Item 10. Directors, Executive Officers and Corporate Governance,”

“Item 11. Executive Compensation,” “Item 12. Security Ownership of Certain Beneficial Owners and Management and Related

Stockholder Matters” and “Item 13. Certain Relationships, Related Transactions, and Director Independence,” which was

filed with the SEC on February 27, 2026, and can be found at www.sec.gov; (b) Safety’s definitive proxy statement for its 2026 annual

meeting of stockholders, which was filed with the SEC on March 31, 2026, under the headings “Proposal 1: Election of the Company’s

Directors,” “Executive Officers,” “Executive Compensation,” “Director Compensation” and “Security

Ownership of Certain Beneficial Owners, Directors and Management,” and can be found at www.sec.gov; and (c) subsequently filed Current

Reports on Form 8-K and Quarterly Reports on Form 10-Q. To the extent holdings of Safety’s securities by its directors or executive

officers have changed since the amounts set forth in Safety’s proxy statement for its 2026 annual meeting of stockholders, such

changes have been or will be reflected on Forms 3, 4 and 5, filed with the SEC (which can be found at www.sec.gov). Investors may obtain

additional information regarding the interests of such participants by reading the definitive proxy statement, including under the heading

“The Merger—Interests of Directors and Executive Officers in the Merger,” and other relevant materials regarding the

proposed transaction when they become available. Copies of the documents filed with the SEC by Safety will be available free of charge

through the website maintained by the SEC and at Safety’s website at https://www.safetyinsurance.com/about/financial.html.

Cautionary Statement

Regarding Forward-Looking Statements

This Current Report on

Form 8-K contains “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended,

Rule 175 promulgated thereunder, Section 21E of the Securities Exchange Act of 1934, as amended, and Rule 3b-6 promulgated thereunder.

Such statements include statements concerning anticipated future events and expectations that are not historical facts. Any statements

about Safety’s plans, objectives, expectations, strategies, beliefs, or future performance or events constitute forward-looking

statements. Forward-looking statements are typically identified by words such as “believe,” “expect,” “anticipate,”

“intend,” “target,” “estimate,” “continue,” “positions,” “plan,”

“predict,” “project,” “forecast,” “guidance,” “goal,” “objective,”

“prospects,” “possible” or “potential,” by future conditional verbs such as “assume,”

“will,” “would,” “should,” “could” or “may,” or by variations of such words

or by similar expressions or the negative thereof. Such forward-looking statements include but are not limited to statements about the

benefits of the proposed transaction, including future financial and operating results, Safety’s plans, objectives, expectations

and intentions, the expected timing of completion of the proposed transaction and other statements that are not historical facts. Actual

results may vary materially from those expressed or implied by forward-looking statements based on a number of factors, including, without

limitation: (a) risks related to the consummation of the proposed transaction, including the risks that (i) the proposed transaction may

not be consummated within the anticipated time period, or at all, (ii) Safety may fail to obtain stockholder approval of the Merger Agreement,

(iii) the parties may fail to obtain required governmental and regulatory approvals, including, without limitation, from the Massachusetts

Commissioner of Insurance, and (iv) other conditions to the consummation of the proposed transaction under the Merger Agreement may not

be satisfied; (b) the effects that any termination of the Merger Agreement may have on Safety’s business, including the risk that

Safety’s stock price may decline significantly if the proposed transaction is not completed; (c) the effects that the announcement

or pendency of the proposed transaction may have on Safety’s businesses, including the risks that as a result (i) Safety’s

business, operating results or stock price may suffer, (ii) Safety’s current plans and operations may be disrupted, (iii) Safety’s

ability to retain or recruit key employees may be adversely affected, (iv) Safety’s business relationships (including customers,

policyholders, agents, service providers, and business partners) may be adversely affected, or (v) Safety’s management’s or

employees’ attention may be diverted from other important matters; (d) the effect of limitations that the Merger Agreement places

on Safety’s ability to operate its business, return capital to stockholders or engage in alternative transactions; (e) the nature,

cost and outcome of pending and future litigation and other legal proceedings, including any such proceedings related to the proposed

transaction and instituted against Safety and others; (f) the risk that the proposed transaction and related transactions may involve

unexpected costs, liabilities or delays or that the potential benefits of the proposed transaction may not be realized or will not be

realized within the expected time period and that Safety and Mapfre will not be integrated successfully or that such integration may be

more difficult, time-consuming or costly than expected; (g) other economic, business, competitive, legal, regulatory, and/or tax factors;

and (h) other factors described in the reports of Safety filed with the SEC, including but not limited to the risks described in Safety’s

Annual Report on Form 10-K for its fiscal year ended December 31, 2025, which was filed with the SEC on February 27, 2026, and Safety’s

Quarterly Reports on Form 10-Q, and that are otherwise described or updated from time to time in Safety’s other filings with the

SEC. All forward-looking statements attributable to Safety, or persons acting on Safety’s behalf, are expressly qualified in their

entirety by this cautionary statement. Further, Safety disclaims any obligation to update the information in this Current Report on Form

8-K or to announce publicly the results of any revisions to any of the forward-looking statements to reflect future events or developments,

except as otherwise required by law. Stockholders are cautioned not to place undue reliance on these forward-looking statements that speak

only as of the date hereof.

SIGNATURES

Pursuant to the requirements

of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto

duly authorized.

Safety Insurance Group, Inc.

Date: September 15, 2026

By:

/s/ CHRISTOPHER T. WHITFORD

Name:

Christopher T. Whitford

Title:

V.P., Chief Financial Officer and Secretary

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