While you’re eligible for Medicare at age 65, you’re automatically enrolled only if you’re already receiving Social Security or Railroad Retirement Board benefits at least four months before your 65th birthday. Otherwise, you need to take steps to sign up yourself.
When is the earliest I can enroll in Medicare?
Unless you qualify for Medicare before age 65 because of a disability, the first time you’re eligible to sign up is during your initial enrollment period (IEP), which begins on the first day of the month three months before the month you turn 65 and lasts for three months after your birthday month. This is different than an SEP.
So if you’re a few months past your 65th birthday, you still may be in your initial enrollment period. Where you are in your IEP determines when your Medicare coverage starts:
- If you enroll during those first three full months before your birthday, your coverage begins on the first day of the month you turn 65 or the first day of the previous month if your birthday is on the first of the month.
- If you sign up during the month you turn 65 or the three months after your birthday month, coverage begins on the first day of the following month.
The rules changed in 2023. Coverage used to be delayed two or three months if you signed up after your birthday month.
What if I’m past my initial enrollment period?
If you qualify for premium-free Part A, like most people, you can sign up for that coverage during your initial enrollment period or any time after without a penalty. Your Part A coverage is retroactive for up to six months but no earlier than the month you turned 65.
Part B isn’t as flexible. If you missed your initial enrollment period, you may be able to sign up later without penalty if you qualify for a special enrollment period.
You can qualify for a special enrollment period if you or your spouse is still working and you have health insurance from that employer. This can’t be coverage from your former employer’s plan through COBRA, the federal Department of Veterans Affairs, military retiree health coverage from Tricare, a labor union retiree plan or any other retiree health plans. You or your spouse must be actively working for the company providing the insurance.
If so, you can delay signing up for Medicare while you have that coverage. And your SEP lasts from the time you turn 65 up to eight months after the employment or coverage ends, whichever occurs first.
Starting in 2023, you may also qualify for a special enrollment period in other circumstances, including if you missed your initial enrollment period because of a natural disaster.