Medicare sets the rules on who pays first (who is primary) so you really don't get a choice.
If you are covered under an employer group health insurance plan, and the company has fewer than 20 employees, then Medicare is primary, your group health plan is secondary.
But if there are 20+ employees the group plan is primary.
If you are covered under an employer group health insurance plan, and the company has fewer than 20 employees, then Medicare is primary, your group health plan is secondary.
But if there are 20+ employees the group plan is primary.