A person (or a person’s spouse) with group health coverage through a current employer may be able to delay enrolling in Part A and Part B until that coverage ends, and won’t face penalties for enrolling later, but only if the employer has 20 or more employees. If your wife’s employer has at least 20 employees, you may want to enroll in Part A (if you qualify for premium-free Part A) but delay enrollment in Part B until your group coverage through your spouse’s employer plan ends.

If you are already receiving Social Security benefits, you will be automatically enrolled in Part A and Part B when you turn 65. If you do not want to pay a premium for Part B benefits now because you have comparable coverage under your spouse’s employer plan, you will need to let Social Security know that you want to delay Medicare Part B enrollment. You can contact Social Security about this beginning three months before you turn 65. Otherwise, Medicare will assume you want to enroll in Part B and the monthly premium will be automatically deducted from your Social Security check.

If the employer has fewer than 20 employees, you should sign up for Part A and Part B when you’re first eligible or you will face late enrollment penalties.

If you do delay Part B enrollment because you are covered under your wife’s plan, remember to sign up for Part B once her coverage ends. That way, you’ll have continuous coverage and won’t face a late enrollment penalty for Part B.