How to Enroll in Medicare: A Step-by-Step Checklist

Start by gathering what you'll actually need: your Social Security number and a form of identification such as a birth certificate. Having these ready before you start the application prevents the most common source of delay, which is stopping partway through to go find a document.

If you haven't already filed for Social Security benefits, you'll need to actively apply for Medicare Parts A and B. Create or log into your my Social Security account at SSA.gov, and either complete the application online or schedule a phone or in-person appointment if your situation is more complicated (for instance, if you're enrolling based on a qualifying disability or a Special Enrollment Period after losing employer coverage). Review the application carefully before submitting, since correcting a submitted application takes longer than getting it right the first time. If you've already filed for Social Security benefits before turning 65, this step happens automatically and you can skip straight to confirming your enrollment once your card or letter arrives.

Once your application is processed, confirm your enrollment. You can get your Medicare number and coverage start date either by downloading your Benefit Verification Letter from SSA.gov once it's available or by waiting for your physical Medicare card to arrive in the mail. From there, create or log into your account at Medicare.gov using that Medicare number to review your coverage details. This is also the point to sort out how your premiums will actually be paid, whether that's a deduction from your Social Security benefit, a quarterly Medicare bill, or enrolling in Medicare Easy Pay for automatic electronic payment, since the default method isn't always the one you'd choose if you knew the options existed.

If your situation calls for it, this is the stage to complete enrollment in Medicare Advantage (Part C), a standalone prescription drug plan (Part D), or a Medigap supplemental policy, through Medicare.gov or directly with the insurance carrier you or your advisor selected. Original Medicare alone (Parts A and B) leaves real gaps, no out-of-pocket maximum, no drug coverage, so most people pair it with one or more of these before their coverage start date arrives, not after.

After coverage begins, the process isn't quite done. Keep copies of your enrollment confirmations, plan selections, and premium notices, and keep an eye on your mail and online accounts for anything that needs a response. Medicare-related scams are common and specifically target new enrollees, unsolicited phone calls, emails, or texts claiming to be from Medicare asking for your Medicare number or payment information are never legitimate. Medicare and Social Security will not call you out of the blue asking you to verify your number or pay a fee to keep your coverage active.

If you're within a few months of turning 65 and haven't yet filed for Social Security, put the SSA.gov application on your calendar now rather than waiting for a reminder. The Initial Enrollment Period is unforgiving: missing it without a qualifying Special Enrollment Period creates permanent late-enrollment penalties on Part B and Part D that follow you for the rest of your life.

Once you enroll, tell your financial advisor your coverage start date and what you selected for Part C, D, or Medigap. That information feeds directly into the income and tax planning happening around the same years, particularly because a large Roth conversion or asset sale in the two years before Medicare starts can raise the premium you pay after it starts, through IRMAA.

• Waiting to gather your Social Security number and identification until you're already mid-application, which is the single most common source of avoidable delay.
• Assuming Parts A and B enroll automatically in every case. They only do if you're already collecting Social Security benefits before 65; otherwise, you have to actively apply.
• Skipping Part C, D, or Medigap entirely because original Medicare seems like enough coverage, without accounting for the fact that it has no out-of-pocket maximum and doesn't cover prescription drugs on its own.
• Responding to an unsolicited call, email, or text claiming to be from Medicare and asking for your Medicare number or a payment. Medicare does not initiate contact this way.