Final answer:
The primary health insurance policy for a patient with two group insurance plans typically is the one provided through their own employer, while the plan through a spouse's employer would be secondary.
Step-by-step explanation:
The question at hand involves determining which health insurance policy should be billed as primary when a patient holds two different group insurance plans. In general, the primary health insurance will be the one that is provided to the patient through their own employer.
This is in line with the standard coordination of benefits rules, where a person's own employer-based health insurance typically takes precedence over the one provided by a spouse's employer. As for the other policy, it will be considered secondary and may cover some remaining costs not covered by the primary insurance.