Text Size:A A A

Other Health Insurance/Coordination of Benefits

Some people with Medicare also have another insurance plan or health care coverage. If you do, there are rules that say who will pay your doctor first and who will pay the rest of the bill. This is called Coordination of Benefits, or COB.

When you join Medicare, you will get an Initial Enrollment Questionnaire. The form lets Medicare know if you have other insurance. This way, Medicare will know who should pay which parts of your medical bills. Then it can process your claim.

Who pays first?

If you get your health coverage through your current job or your spouse's this insurance will probably cover you first, before Medicare pays anything. It is always best to double check with your job's health insurance plan administrator.

If you have retiree health insurance, Medicare usually pays first. Then your retiree plan fills in some of the remaining gaps. You can read how your plan works with Medicare in your other insurance plan booklet.

You can learn a lot more about the way Medicare works with other insurance in the official Medicare publication, Who Pays First? This publication also covers Medicare coordination with a wide range of other insurance, such as veterans’ benefits, no fault or liability insurance, COBRA, TRICARE, and more.

What should I do if I have Medicare and other insurance?

Keep these tips in mind when you have other insurance:

  • Make sure your employer has your current contact info.
  • Talk to the benefits administrator of your other insurance before you join Medicare to see how the two work together, and if it is appropriate to take certain parts of Medicare.
  • Educate yourself about the different options available for those new to Medicare.
  • Send in the Initial Enrollment Questionnaire right away.
  • If you need it, get personal help.

  • This field is for validation purposes and should be left unchanged.