2024 Annual Report - With Full Financial Data

Dear Shareholders,

In late February, we shared financial results for 2024 that clearly demonstrated the progress ProAssurance has made over the past year to keep us on track toward our long- term financial and operational objectives in the face of continuing headwinds in the cyclical markets we serve. Net income for the year was $52.7 million, or $1.03 per diluted share, and Non-GAAP operating income was $48.6 million, or $0.95 per diluted share, compared with losses in 2023. We are successfully executing on our strategic priorities and reaching key performance milestones, while continuing to provide our insureds and distribution partners the insurance protection and service excellence they know they should expect.

In March, we announced that ProAssurance has agreed to be acquired by The Doctors Company, the nation's largest physician-owned medical malpractice insurer, for $25 per share in cash. The transaction delivers significant value to our shareholders and affirms the progress we have made over the past several years. We believe it reflects recognition by a fellow medical professional liability industry leader - with a history very similar to ours - of the long-term value that we are creating.

Combined strengths of ProAssurance and The Doctors Company will create a premier medical malpractice company

Both ProAssurance and The Doctors Company were founded by physicians in response to the medical liability crisis of the 1970s. Both companies have grown over the years by bringing together other physician-founded companies. This shared history has helped both companies fulfill our shared mission to protect others and has given us similar operating philosophies and cultures.

If consummated, the transaction will solidify the combined organization as the second- largest medical malpractice insurance company in the country and the largest physician- owned carrier. Our combined strengths will position us to be the preferred choice of our distribution partners and healthcare clients. Together, we will have the depth of products, defense expertise, risk management and service to compete even more effectively across the country.

This annual report accompanies the proxy statement for our annual stockholder meeting. At that meeting shareholders will elect three directors to the board, ratify the appointment of our independent auditors, and offer an advisory vote on compensation for our named executive officers.

We will be scheduling a special meeting of ProAssurance stockholders to approve the transaction with The Doctors Company. Additional information about that meeting will be available in a separate proxy statement that we intend to file with the SEC and distribute to shareholders in the coming weeks. In addition to shareholder approval, the transaction requires regulatory approval, including approvals from insurance regulators in a number of states, and antitrust clearance. Subject to the receipt of those approvals and other customary closing conditions, the transaction is expected to close in the first half of 2026.

1

Non-GAAP operating earnings improved sequentially each quarter in 2024 and our confidence continues to grow that actions we have taken over the past several years have us on track to achieve our objectives

In a sign that our multi-year effort to respond to rising medical professional liability severity is generating positive results, our Specialty P&C segment delivered a full-year combined ratio of 104.5%, including net favorable prior accident year reserve development of 5.0 points. This segment, which is largely made up of our Medical Professional Liability line of business, represents more than 75% of total earned premium.

Continuing social inflation and eroding tort reform mean we are still facing a challenging environment, exacerbated by legal system abuse. We believe we have stayed ahead of many in the space in achieving rate levels in medical professional liability that outpace the resulting severity trends. We have achieved more than 20 points of improvement in the accident year loss and loss adjustment expense ratio since 2019, due to renewal premium increases as well as the impact of our re-underwriting efforts and other strategic initiatives.

Even with the progress of this past year, work remains. We continue to forgo renewal and new business opportunities that we believe do not meet our expectation of rate adequacy in the current loss environment. Renewal premium increases in 2024 were 10% for our standard medical professional liability business and 13% for the specialty portion of our business. This brings renewal premium increases since 2018 within this line of business to almost 70 percent cumulatively.

Exclusive of rate changes, retention of our existing premiums was a solid 84%, including strong retention in the standard book. As expected, new business continues to be impacted by our focus on rate adequacy and was below the prior year's level.

Complementing our focus on pricing is our commitment to disciplined underwriting and managing claims to address market conditions. Innovation tools continue to enhance our risk selection, pricing decisions and workflows. As we've said, predictive analytics allow us to leverage our extensive data and help us identify specific geographic markets and specialty sub-sectors where there are opportunities to write business that we believe will meet our profitability objectives.

We're also committed to ensuring that our insureds and distribution partners find us easy to do business with - helping distinguish us in the marketplace. In late 2024, we launched an AI-ready web portal that delivers a variety of enhanced self-service options for policyholders and agents, and we are enhancing workflows using the functionality of the new system.

Turning to our Workers' Compensation Insurance segment, we continue to carefully manage our underwriting appetite as we work to obtain the necessary rate. Our focus is on addressing the higher medical loss trends that we initially saw in mid-2023, although those trends had moderated by the end of 2024. Net written premiums were up only $4 million for the year, reflecting higher audit premiums and improved renewal pricing, while new business in our traditional book was more than $4 million below last year. In addition, we believe our focus on operational discipline is having a positive impact with the combined ratio improved compared with 2023.

2

The progress we are making has been due, in part, to our ability to leverage the integrated policy, claims, risk management and billing system we implemented in early 2024. Not only is that system working well, it is also paving the way for innovation initiatives that will help us address the challenging market conditions. These initiatives are using AI tools - along with underwriting and claims data analytics - to enhance profitability, productivity and efficiency.

Investment results contributed strong results for the year as we continue to manage our asset duration to largely match that of our liabilities and to optimize our portfolio to generate yield

Net investment income rose 13 percent for the year, as we continue to take advantage of the rate environment. New purchase yields for the year for the consolidated portfolio were approximately

5.8 percent - or 230 basis points higher than our average book yield of 3.5 percent. The fixed maturity portfolio remains high quality with 93 percent in investment-grade bonds with an average duration of 3.2 years. Our investments in limited partnerships and LLCs - reported as equity in earnings of unconsolidated subsidiaries - added another $22 million to earnings for the year, up $12 million from 2023.

Reported book value per share at year-end 2024 rose by $1.67 from year-end 2023 to $23.49. Non-GAAP adjusted book value per share also increased, rising to $26.86, which included $1.17 attributable to goodwill and intangible assets, resulting in a Non-GAAP adjusted tangible book value per share of $25.69. Non-GAAP adjusted tangible book value per share is calculated as total shareholders' equity, excluding AOCI, goodwill and other intangible assets, divided by the total number of common shares outstanding at the balance sheet date.

Across the organization, we remain intently focused on delivering on the promise of our mission: To Protect Others

We are pleased with the progress of 2024 and excited about what the future holds. Our long history in both medical professional liability and workers' compensation has taught us that these cyclical lines will respond to our focused efforts. On behalf of our board and our management team, I thank our more than 1,000 dedicated team members for their commitment to understanding and providing solutions for the risks our customers encounter as healers, innovators, employers,

and professionals. We also thank our shareholders for the confidence you have placed in us.

As we work through the steps toward our future as part of The Doctors Company, we remain intently focused on delivering on the promise of our mission: To Protect Others.

Thank you again for your support.

Sincerely,

Ned Rand, President and Chief Executive Officer

April 11, 2025

3

4

Board of Directors and Executive Officers

5

Stock Price Performance

You may use the following information to compare the market value of our Common Stock to that of other public companies in general, and public companies in the insurance industry. The graph shows the cumulative total shareholder return of our stock, as well as the cumulative total shareholder return of the Russell 2000 Index and the S&P Composite 1500 Property & Casualty Index for the five years ended December 31, 2024. We have also included the Standard & Poor's 500 Index in this graph because it is a recognizable broad index.

Five-year total return for ProAssurance and indices

6

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF

• 1934

For the fiscal year ended December 31, 2024,

or

TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT

• OF 1934

Commission file number: 001-16533

ProAssurance Corporation

(Exact name of registrant as specified in its charter)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None.

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☒ No ☐

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ☐ No ☒

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.

1

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 Section13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C.

7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☒

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant's executive officers during the relevant recovery period

pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes ☐ No ☒

The aggregate market value of voting stock held by non-affiliates of the registrant at June 30, 2024 was $617,056,208. As of February 20, 2025, the registrant had outstanding approximately 51,156,821 shares of its common stock.

Documents incorporated by reference in this Form 10-K

1. The definitive proxy statement for the 2025 Annual Meeting of the Stockholders of ProAssurance Corporation (File No. 001-16533) is incorporated by reference into Part III of this report.

2