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When Does Medicare Start After Signing Up?

Depending on what specific part of Medicare you are enrolling in, the timing of your enrollment can have a major impact on your coverage.

3 mins read
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Are you planning on retiring soon? Then you may want to know: when does Medicare start?

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Does Medicare start on my 65th birthday?

You are eligible for Medicare if you are an American (or a US resident for five years) aged 65 and above, or if you are under 65 and have been receiving disability benefits for at least 24 months.

If you are already receiving Social Security or Railroad Retirement (RRB) benefits, you are automatically enrolled in Original Medicare when you turn 65.

Otherwise, you should proactively enroll in Original Medicare when you turn 65.

When does Medicare kick in for Original Medicare?

When your coverage under Original Medicare begins, you will have Part A (Hospital) and Part B (Medical) benefits.

The best time to enroll is during your Initial Enrollment Period (IEP) – a seven-month period that starts three months before turning 65.

Signup DateStart of Coverage
Any time in the three months before your birth month1st day of birth month
During your birth month1st day after birth month
Note: If your birthday falls on the 1st of the month, coverage starts on 1st day of the previous month
One month after birth monthTwo months after signup
Two to three months after birth monthThree months after signup
Initial Enrollment Period – When does coverage start?

If you missed your IEP, the nearest enrollment period is the General Enrollment Period (GEP) – January 1 to March 31. Coverage starts the month after you apply.

When does coverage start under a Medigap plan?

A Medigap plan will help in paying the out-of-pocket costs that you are required to pay under Original Medicare.

During the Medicare Supplement OEP, you have ‘guaranteed issue rights.’ This means that private insurers cannot deny coverage or charge you more based on your health condition.

Signup DateStart of Coverage
You can purchase a Medicare Supplement plan anytime during the year if you are on Original Medicare.

Note: The Medicare Supplement Open Enrollment Period is the 6-month period starting on the 1st day your Part B coverage starts or is in effect after your 65th birthday. During this period you have ‘guaranteed issue’.
You can select the date you want to enroll.
Medicare Supplement Open Enrollment Period – When does coverage start?

It may be more difficult to get a Medigap plan after this one-time guaranteed as you will need to answer health questions or pay more to cover pre-existing health problems.

What month does Medicare start if I choose a Medicare Advantage plan?

Many seniors enroll in Medicare Advantage (or Part C) plans, in part because of the additional benefits these plans offer. These are the enrollment periods:

Signup DateStart of Coverage
Initial Enrollment PeriodTypically same as Original Medicare
Annual Enrollment Period (AEP) October 15 to December 7January 1 of the following year
MA Open Enrollment Period (MA-OEP) January 1 to March 311st day of the month after your request is received
Medicare Advantage – When does coverage start?

When does Medicare coverage start for Part D plans?

You may need a standalone prescription drug plan (PDP) under traditional Medicare. You can enroll during these enrollment periods:

Signup DateStart of Coverage
Initial Enrollment Period (IEP)Typically same as Original Medicare
Annual Enrollment Period (AEP) October 15 to December 7January 1 of the following year
Standalone Part D Prescription Drug Plans – When does coverage start?

When does Medicare coverage start if I switch plans?

You can switch plans during these periods:

Signup DateStart of Coverage
Annual Enrollment Period (AEP)January 1 next year
MA Open Enrollment Period (MA-OEP)1st day of the month after your request is received
Special Enrollment Period (SEP)
Note: Under special circumstances only
1st day of the month after the qualifying event
Medicare – When does coverage start?

At what age does Medicare start if I continue working?

Most seniors are covered by premium-free Part A if they have contributed Medicare taxes for ten years.

If you continue working after 65, you can defer Part B enrollment (without penalties) as long as you have ‘creditable coverage.’ This term refers to a situation where you (or your spouse) have job-sponsored medical and drug insurance equivalent to Medicare.

Your next question might be – When can I start Medicare if I stop working?

If you lose creditable coverage, these are your enrollment periods:

Signup DateStart of Coverage
Part A (if qualified for free premiums)Anytime (no penalty)Retroactive coverage for a maximum of 6 months if you did not get it when you turned 65
Part BEight-month period after your employer coverage ends1st day of the month after you signup
Medicare Advantage / Part D Drug PlanWithin 63 days of losing employer coverage1st day of the month after you signup
Retiring – When does coverage start?

Final Words

It is important to enroll in Medicare during the correct time periods. If you miss these enrollment periods, you may face higher premiums, penalties, and fewer options.

The CoverRight team is here to help you navigate your Medicare options and find the plan that works best for you!

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Josef Katz

Josef is a digital marketing expert, is a podcast host of PrimeLife and formerly a licensed insurance agent. Josef has had an extensive career across the education, healthcare, insurance and financial services sectors and is passionate about educating consumers.