25 Largest Workers Compensation Insurers

The Workers Comp Market Is Diverse

Worker compensation. Work injury claim on a table.

Workers compensation insurance is widely available, but some insurers write more policies than others. This is evident from the Top 25 list that appears below. The latest list is derived from data published by the National Association of Insurance Commissioners (NAIC) in March 2019. The NAIC is an advisory organization that sets standards and provides regulatory advice to state insurance departments.

Varied Market

The workers compensation market is highly varied. The Top 25 list includes a conglomerate, several large multi-line insurers, some specialty companies, and four state insurance funds. Berkshire Hathaway (third on the list) is a conglomerate that owns more than a dozen insurance companies, including GEICO and General Re. Travelers, Hartford, and Zurich (first, second and fourth, respectively) are large insurers that provide a broad range of coverages to businesses of all sizes.

Some insurers on the list, like W.R. Berkley and Markel, are specialty companies. W.R. Berkley owns dozens of insurance companies, each of which specializes in a certain type of business. For instance, Berkley Agribusiness focuses on commercial agriculture while Preferred Employers Insurance provides workers compensation insurance to businesses in California. Markel specializes in market niches like farming, livestock, education, and sports. It also offers a small business program that includes coverages like workers compensation and businessowners.

Workers Comp Specialists

Interestingly, four of the largest workers compensation insurers are state funds. These include the New York State Fund, the State Compensation Fund of California, Pinnacol Assurance (the state fund in Colorado), and Texas Mutual. All compete for business with private insurers and all operate their state's assigned risk plan. Assigned risk plans provide workers compensation coverage to employers that are unable to obtain insurance from a standard insurer.

The Top 25 list includes the state insurance funds of New York, California, Colorado, and Texas.

A few insurers on the list are workers compensation specialists but aren't state funds. These include Employers Group and ICW Group. Employers Group offers workers compensation coverage only. It operates in 45 states and focuses on small businesses. ICW Group sells only two commercial insurance coverages: workers compensation and earthquake. 

Blue Cross Blue Shield of Michigan is a health insurer and the parent company of Accident Fund Group. The latter owns several subsidiaries that sell workers compensation insurance only.

The Top 25

The insurers on the "top 25" list appear in descending order based on direct written premiums generated in 2018. The term direct written premium means all policy premium collected by an insurer without considering any premium ceded to reinsurance companies. The written premium is the amount a policyholder is obligated to pay for a policy. Workers compensation premiums are paid in advance so the written premium is the amount the insured has paid upfront. Written premium differs from earned premium, which is the amount the insured has paid for the expired portion of the policy. The earned premium is based on actual payrolls so it cannot be calculated until a final audit is performed.

Insurers' workers compensation premiums can fluctuate from year to year. Some insurers may lose market share due to competition or declining premiums. Others may deliberately write fewer policies. For instance, an insurer may decide to exit an unprofitable line of coverage or sell a book of business to another insurer. 

While their rankings may change somewhat, the same insurers tend to appear on the Top 25 list each year.

Although their rankings may fluctuate, the insurers that appear on the Top 25 list don't change much from year to year. The current list includes only one insurer that wasn't on the previous list. In 2019, Everest Reinsurance Holdings was added while SAIF Corp. was deleted. Everest Reinsurance Holdings owns insurance and reinsurance subsidiaries that operate around the world. SAIF Corp. operates the state insurance fund in Oregon.

25 Largest Workers Compensation Insurers
Rank Insurer 2018 Premium 2018 Market Share (%)
1 Travelers Group 4.280 bn 7.38
2 Hartford Group 3.382 bn 5.83
3 Berkshire Hathaway 2.750 bn 4.74
4 Zurich Ins. Group 2.694 bn 4.65
5 AmTrust Group 2.635 bn 4.54
6 Chubb Ltd. Group 2.478 bn 4.27
7 Liberty Mutual Group 2.473 bn 4.27
8 State Ins. Fund (NY) 2.256 bn 3.89
9 AIG 1.690 bn 2.91
10 BCBS of MI Group 1.566 bn 2.70
11 Old Republic Grp. 1.466 bn 2.53
12 WR Berkley Corp. Grp. 1.360 bn 2.35
13 State Comp. Ins. Fund (CA) 1.338 bn 2.31
14 American Financial Grp. 1.328 bn 2.29
15 Texas Mutual Ins. Co. 1.097 bn 1.89
16 ICW Group 958 M* 1.65
17 Fairfax Financial Grp. 928 M 1.60
18 CNA Ins. Group 800 M 1.38
19 Employers Holding Group 739 M 1.27
20 Starr Group 649 M 1.12
21 Pinnacol Assurance 623 M 1.08
22 Arch Ins. Group 581 M 1.00
23 Markel Corp. Group 530 M .91
24 NJ Manufacturers Group 519 M .90
25 Everest Reins. Holdings Grp. 512 M .88
  Industry Total 57,996 bn


Source: NAIC's Market Share Report, March 25, 2019