Hartzell Insurance Associates, Inc.
- Aetna
- Aflac
- AIG
- American Collectors
- Amerisafe
- Berkshire Hathaway GUARD
- Capital Blue Cross
- Chubb
- CNA
- Cumberland Insurance Group
- Donegal
- Encompass
- Foremost
- Hanover
- Hartford
- Hartford Steam Boiler
- Hospitality Ins.
- Kemper
- Liberty Mutual
- MetLife
- Mutual Benefits Assurance
- Progressive
- QBE
- Safeco
- Selective
- State Auto
- The Philadelphia Contributionship
- Travelers
- United Marine Underwriters
- Westfield Insurance
- Zenith