Medicare works in tandem with your other health insurance coverage. The two tag team. One insurance plan becomes the primary payer or the one that pays costs first. The other insurance becomes the secondary payer and pays the remaining costs. However, just because the secondary payer is left with the remaining costs does not mean it must pay 100% of the leftover costs.
Which insurance pays first depends on the type of insurance you have. For instance, if you have retiree insurance, Medicare pays first. If you have an employer group plan, who pays first depends on factors such as your age and the size of the company.
For additional information on how Medicare works with other insurance, visit http://go.usa.gov/loH for the publication “Who Pays First” or call 1-800-633-4227.