25 Largest Workers Compensation Insurers

Woman lying on a bed with a broken leg
Image courtesy of [Julian James Ward] / getty Images.

What are the largest workers compensation insurers in the United States? As you can see from the list below, Travelers and Hartford generated the most workers compensation premium in 2015. Other top providers were Zurich Insurance Group, the AmTrust Group, and AIG.

The list is derived from data published by the National Association of Insurance Commissioners (NAIC) in March of 2016. The NAIC sets standards and provides regulatory advice to insurance regulators in the U.S. The organization has existed since 1871.

Among other things, the NAIC creates model laws that states may adopt, either "as is" or with modifications. This saves states time and effort, and helps standardize laws and regulations across the country.

Varied Market

The insurers listed below represent a varied market for workers compensation insurance. The list includes large multi-line insurers, smaller specialty insurers, and several state insurance funds. Examples of big insurers are Travelers, Hartford, AIG and Zurich. These are some of the largest insurers in the U.S. They provide a wide variety of insurance coverages, not just workers compensation. Most sell insurance through independent agents.

AmTrust, which is number four on the list, specializes in workers compensation and package policies for small to mid-sized companies. It is based in New York City, and operates across the U.S.

A few of the insurers cited below are workers compensation specialists.

Examples are Employers Insurance and Texas Mutual. These insurers offer workers compensation coverage only. They do not provide any other type of insurance. Employers Insurance operates in about two-thirds of the states and focuses on small businesses. Texas Mutual sells policies to Texas employers only.

It formerly served as the state insurance fund. However, it currently operates as a mutual insurer that competes with private insurance companies.

Interestingly, three insurers on the top 25 list are state insurance funds. These include the New York State Fund, the State Compensation Fund of California, and SAIF (the state fund for Oregon). All are self-supporting non-profit companies that compete for business with private insurers in the standard market. Both the New York and California funds also operate the state's assigned risk plan.

The Top 25

The premiums shown in the table below are net written premiums. This term means all policy premiums collected by an insurer except for premiums paid to a reinsurance company for reinsurance coverage. Insurers' workers compensation premiums can fluctuate from year to year. Some changes may be deliberate. For instance, both AIG and Liberty Mutual have experienced a significant drop in workers compensation premiums in recent years. Both companies have stated that the decline was intentional, and reflected their decision to exit unprofitable business.

One company that has disappeared from the top 25 list is ACE. In 2016, ACE purchased Chubb, and the combined company is using the Chubb name.

Both Chubb Ltd. Group and Chubb Insurance Group appear in the list below. Chubb Ltd. Group is the parent company of the Chubb Insurance Group.

RankInsurer2015 Premium (MM)2015 Market Share
1Travelers Group4,4677.81
2Hartford Group3,3245.81
3Zurich Ins. Group2,8595.00
4AmTrust Group2,7444.8
5AIG2,5594.48
6Berkshire Hathaway2,4824.34
7Liberty Mutual Group2,4814.34
8State Ins. Fund of NY2,4374.26
9State Comp. Fund of CA1,6382.87
10Old Republic Group1,4442.53
11WR Berkley Group1,3942.44
12American Financial Group1,3142.3
13Chubb Ins. Group1,2442.18
14Chubb Ltd. Group1,1922.09
15BCBS of MI Group1,1391.99
16Texas Mutual Ins. Co.1,0871.90
17Fairfax Financial Group9051.58
18American Assets Group8221.44
19CNA Ins. Group7291.27
20Employers Holding Group6841.2
21Pinnacol Assurance6331.11
22NJ Manufacturers Group509.89
23Nationwide Corp. Group506.89
24Sentry Ins. Group476.83
25SAIF Corp.469.82
 Industry Total57,197100