How to Sign Up for Medicare: Step-by-Step Enrollment Guide for 2026

Signing up for Medicare is either completely automatic or requires deliberate action, depending on whether your parent is already collecting Social Security. There's no in-between, and the consequences of getting it wrong — permanent premium penalties that last the rest of their life — make it worth understanding exactly how enrollment works before the deadline arrives.

This guide walks through every method for enrolling in Medicare, the specific timing windows that matter, and how to handle enrollment when you're helping a parent who may not be able to manage the process alone.

When enrollment is automatic

If your parent is already receiving Social Security benefits when they turn 65, they're automatically enrolled in Medicare Parts A and B. They don't need to do anything. Their Medicare card will arrive in the mail about 3 months before their 65th birthday, and coverage starts the first day of the month they turn 65 (or the first day of the prior month if their birthday falls on the 1st).

If your parent is already receiving Railroad Retirement Board benefits, the same automatic enrollment applies.

Automatic enrollment is straightforward, but there's one catch: if your parent doesn't want Part B (for example, because they have employer coverage and don't want to pay the $185/month Part B premium yet), they need to actively decline it by following the instructions that come with their Medicare card. If they do nothing, they'll start paying the Part B premium.

When your parent needs to actively enroll

If your parent is not receiving Social Security or Railroad Retirement benefits when they turn 65, enrollment is not automatic. This is the more common situation for people who are still working and haven't filed for Social Security yet. They must sign up themselves.

The Initial Enrollment Period (IEP)

The IEP is a 7-month window centered around your parent's 65th birthday:

• 3 months before the birthday month
• The birthday month itself
• 3 months after the birthday month

Example: If your parent turns 65 on June 15, 2026, their IEP runs from March 1 through September 30, 2026.

When coverage starts depends on when within the IEP they sign up:

The takeaway: signing up in the first three months of the IEP means coverage starts the month they turn 65. Waiting until the back half of the window means a gap where they have no Medicare coverage.

Signing up for Part A only vs. Parts A and B

Your parent can choose to enroll in:

• Part A only — makes sense if they have employer coverage and don't need Part B yet. Part A is premium-free for most people and doesn't conflict with most employer plans.
• Parts A and B together — the standard enrollment for people who need Medicare as their primary insurance.

Many people who are still working at 65 enroll in Part A (it's free and provides backup hospital coverage) while delaying Part B (which costs $185/month and may overlap with their employer plan). This is a valid strategy, but only if the employer has 20 or more employees. If the employer has fewer than 20 employees, Medicare is the primary payer and your parent should enroll in both parts.

Three ways to sign up

Online (fastest method)

The fastest way to enroll is through the Social Security Administration website at ssa.gov.

1. Go to ssa.gov and select "Apply for Medicare Only" (or "Apply for Benefits" if also filing for Social Security)
2. Create or sign in to a my Social Security account
3. Complete the online application — it takes about 10-15 minutes
4. Submit the application electronically

Your parent will receive a confirmation number immediately. The Medicare card typically arrives by mail within a few weeks.

This method works best for straightforward enrollments. If your parent's situation involves employer coverage coordination, disability, or end-stage renal disease, the phone or in-person methods may be more appropriate because a Social Security representative can answer questions during the process.

By phone

Your parent can enroll by calling Social Security at 1-800-772-1213 (TTY: 1-800-325-0778). Hours are Monday through Friday, 8:00 AM to 7:00 PM local time.

Wait times vary — they're typically shorter early in the morning and later in the week. Calling in January through March (when General Enrollment is active) means longer wait times.

The representative will walk through the application over the phone. Have the following information ready:

• Social Security number
• Date of birth
• Citizenship or legal residency status
• Current health insurance information (if any)
• Employer information (if still working)

In person

Your parent can visit their local Social Security office. They'll need to make an appointment in advance by calling 1-800-772-1213 or visiting ssa.gov to find the nearest office.

Bring the same documents listed above, plus a photo ID. In-person visits are useful for complex situations — particularly when coordinating with employer coverage, handling a disability enrollment, or resolving issues with an existing application.

Signing up for Part B specifically

If your parent already has Part A (either through automatic enrollment or because they signed up for Part A only) and now needs to add Part B, the process depends on their timing:

During the Initial Enrollment Period: They can sign up for Part B through the same channels above (online, phone, or in person) as part of their initial enrollment.

During the General Enrollment Period (January 1 - March 31): If your parent missed their IEP and doesn't qualify for a Special Enrollment Period, they can sign up for Part B during the GEP. Coverage starts July 1 of that year. They'll also face the late enrollment penalty.

During a Special Enrollment Period (SEP): If your parent has been covered by an employer plan (their own or their spouse's, through an employer with 20+ employees), they qualify for an 8-month SEP starting when the employment or the employer coverage ends — whichever comes first. They must complete Form CMS-L564 (Request for Employment Information) to verify the employer coverage and file it with their Part B application.

The SEP is the most commonly misunderstood enrollment window. The 8-month clock starts when employment or coverage ends — not when COBRA ends. COBRA is not creditable coverage for Part B purposes, and waiting for COBRA to expire before enrolling in Part B will trigger a penalty.

Enrolling on behalf of a parent

If you're the one managing this process for your parent, here's what you need to know about doing it on their behalf.

They can apply with your help

Your parent can sit with you while you help them navigate the online application or fill out forms. As long as your parent is the one signing and authorizing the application, you can provide hands-on assistance with the logistics.

You can apply for them with proper authorization

If your parent cannot manage the enrollment process themselves (due to cognitive decline, physical limitations, or distance), you can apply on their behalf if you have legal authority. Options include:

• Social Security Representative Payee — if you're already their representative payee, you can handle Medicare enrollment
• Power of Attorney — a durable power of attorney may authorize you to handle government benefit applications, though Social Security has its own rules about what it accepts
• Medicare Authorized Representative — completing Form CMS-10106 allows you to interact with Medicare on your parent's behalf for specific matters

For the Social Security application itself, you may need to visit a Social Security office in person if you're applying on behalf of someone who cannot apply for themselves. Bring your POA documentation, your parent's identification, and your own identification.

After enrollment: what happens next

Once enrolled, your parent will receive their red, white, and blue Medicare card in the mail. This card shows their Medicare number, the parts they're enrolled in (Part A, Part B, or both), and the coverage start dates.

Next steps after receiving the card:

1. Decide on supplemental coverage — either a Medigap plan or a Medicare Advantage plan. This decision should happen during the Medigap Open Enrollment Period (6 months starting from Part B enrollment date) for the best Medigap pricing.
2. Enroll in Part D drug coverage — if staying with Original Medicare, they need a separate Part D plan. If choosing Medicare Advantage, most plans include drug coverage.
3. Notify their employer plan — if they have employer coverage that needs to coordinate with Medicare, contact the employer's benefits department.
4. Set up a MyMedicare.gov account — for tracking claims, checking coverage, and managing benefits online.

Don't miss the window

The most common enrollment mistake isn't choosing the wrong plan — it's missing the enrollment window entirely. If your parent is approaching 65 and you're not sure whether they'll be automatically enrolled, check with Social Security at least 3 months before their birthday. A 10-minute phone call now prevents a lifetime of penalties later.

For a complete enrollment timeline, deadline tracker, and the forms you'll need to manage this process for a parent, our Medicare Enrollment Guide walks through every step from initial enrollment through plan selection — built specifically for adult children navigating this for the first time.