Workers' compensation

* American International Group (AIG)
    * Erie Insurance Group
    * Hanover Insurance
    * The Hartford
    * Liberty Mutual
    * Merchants Insurance Group
    * Missouri Employers Mutual
    * Nationwide Mutual Insurance Company
    * Penn National Insurance
    * Sentry Insurance
    * State Accident Insurance Fund
    * State Farm Insurance
    * WellPoint
    * Zenith Insurance Company