Rush Prudential had 302,775 medical plan members as of Sept. 30, the company said.
Vanbreda International serves over 400,000 plan members in 192 countries.
For drugs not on the list, the plan members pay all or a substantial part of the retail price.
Over all, 89 percent of the plan members said they were satisfied, a finding that matches earlier surveys conducted by the plans themselves.
Pension surpluses were not being used to raise pensions for some plan members.
It chose the latter, deciding against any changes that would affect plan members.
Most California doctors are in groups that receive a lump sum from health plans for each plan member.
In many instances, the plan member pays the first $250 in drug costs each year.
And as the insurers changed their products to try to attract plan members, they dropped many of the restrictions that kept costs in check.
But any claims by the policyholders and pension plan members were to be paid first.