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

Last updated 3 days ago. Our resources are updated regularly but please keep in mind that links, programs, policies, and contact information do change.

Medicare provides health insurance for over 66 million Americans, primarily those 65 and older, along with certain younger individuals with qualifying disabilities or specific medical conditions like End-Stage Renal Disease (ESRD) or Amyotrophic Lateral Sclerosis (ALS).

This guide will help you navigate the Medicare enrollment process with clear, actionable steps.

Understanding Medicare: The Basics

Medicare consists of four parts, each covering specific services:

Part A: Hospital Insurance

Part A covers inpatient hospital stays, skilled nursing facility care (after a qualifying hospital stay), hospice care, and some home health care.

Most people receive Part A premium-free if they or their spouse paid Medicare taxes for at least 10 years (40 quarters). Those who don’t meet this requirement can purchase Part A for a monthly premium.

Part B: Medical Insurance

Part B covers outpatient care, doctor visits, preventive services, durable medical equipment, and some home health care. It emphasizes preventive care, covering many screenings and vaccinations.

Unlike Part A, Part B requires a monthly premium for most people. Higher-income individuals pay an additional Income-Related Monthly Adjustment Amount (IRMAA).

Part C: Medicare Advantage

Medicare Advantage plans are offered by private insurance companies that contract with Medicare. They provide all Part A and B benefits, and most include prescription drug coverage. Many offer extra benefits not covered by Original Medicare, such as dental, vision, and hearing coverage.

These plans typically operate with provider networks and may require referrals for specialists.

Part D: Prescription Drug Coverage

Part D helps cover prescription medications. Coverage is available through standalone Medicare Prescription Drug Plans (PDPs) or as part of Medicare Advantage plans (MA-PDs).

Each plan has its own formulary (list of covered drugs) and cost structure. Starting in 2025, out-of-pocket spending for covered drugs will be capped at $2,000 annually.

Checking Your Medicare Eligibility

Who Qualifies?

Age 65 or Older: You must be a U.S. citizen or permanent legal resident who has lived in the U.S. continuously for at least five years.

Under 65 with a Disability: You can qualify after receiving Social Security Disability Insurance (SSDI) benefits for 24 months.

Under 65 with Specific Conditions:

• End-Stage Renal Disease (ESRD): Permanent kidney failure requiring dialysis or a transplant.
• Amyotrophic Lateral Sclerosis (ALS): Automatically eligible when SSDI benefits begin.

The Work History Requirement (for Premium-Free Part A)

To receive premium-free Part A, you generally need 40 quarters of coverage (about 10 years) where Medicare taxes were paid. These quarters can be earned through your own work or through a current, former, or deceased spouse’s work.

In 2025, you earn one credit for every $1,810 earned, up to four credits per year. If you don’t have 40 quarters, you can still enroll by paying a monthly premium.

Medicare Enrollment Windows

Automatic Enrollment vs. Signing Up Yourself

Automatic Enrollment occurs if you:

• Already receive Social Security or Railroad Retirement Board (RRB) benefits at least 4 months before turning 65
• Have received disability benefits for 24 months
• Have ALS and begin receiving disability benefits

Manual Enrollment is necessary if you:

• Are turning 65 but not yet receiving Social Security or RRB benefits
• Qualify based on ESRD
• Qualify for premium-free Part A but didn’t automatically get Part B

Initial Enrollment Period (IEP)

This is your first opportunity to enroll in Medicare:

• It lasts 7 months, beginning 3 months before the month you turn 65, including your birthday month, and ending 3 months after
• For those qualifying through disability, it starts 3 months before your 25th month of disability benefits

If you enroll during the 3 months before your birthday month, coverage starts the first day of your birthday month. If you enroll during or after your birthday month, coverage starts the first day of the month following enrollment.

General Enrollment Period (GEP)

If you miss your IEP and don’t qualify for a Special Enrollment Period:

• Runs January 1 through March 31 each year
• Coverage begins the first day of the month after enrollment
• Late enrollment penalties will likely apply

Special Enrollment Periods (SEPs)

These allow enrollment outside standard periods due to specific life events:

Loss of Employer Coverage: If you delayed Medicare enrollment because you had employer health coverage (yours or your spouse’s), you can enroll:

• While still covered by the group health plan based on current employment
• During the 8-month period after employment or coverage ends, whichever comes first

COBRA or retiree coverage doesn’t count as coverage based on current employment.

Other SEP Triggers include:

• Moving out of a plan’s service area
• Losing Medicaid eligibility
• Plan contract changes
• Natural disasters or emergencies

Step-by-Step: Enrolling in Medicare Part A and Part B

Step 1: Determine if You Need to Enroll Manually

Confirm whether you’ll be automatically enrolled or need to take action. If you’ll receive Social Security benefits before turning 65, expect your Medicare card in the mail about three months before coverage starts.

If you need to enroll manually (e.g., if you’re delaying Social Security benefits), proceed to Step 2.

Step 2: How to Apply

The Social Security Administration (SSA) handles Medicare enrollment. You can apply:

Online (Preferred Method):

• Visit the SSA website
• The application typically takes 10-30 minutes
• You’ll need a my Social Security account or can create one

By Phone:

• Call SSA at 1-800-772-1213 (TTY: 1-800-325-0778)
• Representatives are available weekdays 8:00 AM to 7:00 PM local time

In Person:

• Schedule an appointment at your local SSA office
• Find the nearest office using the SSA office locator

Special Cases:

• Railroad retirees should apply through the RRB at 1-877-772-5772
• For adding Part B later during an SEP, specific forms may be required

Step 3: Information You’ll Need

Gather these details before applying:

• Personal information (full name, Social Security number, date/place of birth)
• Health insurance history, including start/end dates of group coverage
• Documentation for SEP enrollment (if applicable)

Step 4: After You Apply

• Save your confirmation number if applying online
• Allow 2-4 weeks for processing
• Upon approval, you’ll receive a “Welcome to Medicare” packet with your Medicare card
• Track application status through your my Social Security account

Choosing Your Medicare Path

After enrolling in Parts A and B, you need to decide how to receive your benefits.

Original Medicare vs. Medicare Advantage

Original Medicare:

• Traditional fee-for-service program
• Freedom to use any Medicare-accepting provider nationwide
• No network restrictions or referral requirements
• No cap on out-of-pocket expenses unless you add a Medigap policy
• Requires separate enrollment in Part D for prescription coverage

Medicare Advantage:

• Private health plans (HMOs, PPOs) approved by Medicare
• Must use providers in the plan’s network (especially for HMOs)
• Often includes prescription drug coverage and extra benefits
• Has an annual out-of-pocket maximum for Part A and B services
• Cannot be used with Medigap policies

Adding Prescription Drug Coverage (Part D)

Consider enrolling in Part D when first eligible to avoid penalties later.

With Original Medicare: Enroll in a standalone Medicare Prescription Drug Plan (PDP).

With Medicare Advantage: Choose an MA plan that includes drug coverage (MA-PD).

Use the Medicare Plan Finder to compare plans based on your medications, preferred pharmacies, and location.

Adding Medicare Supplement Insurance (Medigap)

If choosing Original Medicare, consider a Medigap policy to help cover out-of-pocket costs.

Best Time to Buy: During your 6-month Medigap Open Enrollment Period, starting when you’re both 65+ and enrolled in Part B. During this window, insurance companies must sell you any Medigap policy they offer, regardless of health conditions.

Outside this Window: Companies can deny coverage or charge higher premiums based on your health.

Steps to enroll:

1. Choose a plan letter (A-N) based on your coverage needs
2. Compare prices from different companies using the Medigap policy search tool
3. Contact the company to apply

Medicare Costs in 2025

Part A (Hospital Insurance)

• Premium: $0 for most people; $285/month with 30-39 quarters of coverage; $518/month with fewer than 30 quarters
• Inpatient Hospital Deductible: $1,676 per benefit period
• Hospital Coinsurance:
  • Days 1-60: $0 after deductible
  • Days 61-90: $419 per day
  • Days 91+ (Lifetime Reserve Days): $838 per day
• Skilled Nursing Facility Coinsurance:
  • Days 1-20: $0
  • Days 21-100: $209.50 per day
  • Days 101+: All costs

Part B (Medical Insurance)

• Standard Monthly Premium: $185.00
• Annual Deductible: $257
• Coinsurance: 20% of Medicare-approved amount for most services
• Higher-income beneficiaries pay additional IRMAA amounts

Part D (Prescription Drug Coverage)

• Premium: Varies by plan (average about $46.50/month)
• Deductible: Varies; maximum $590 in 2025
• Annual Out-of-Pocket Cap: $2,000 starting in 2025
• Higher-income beneficiaries pay additional amounts

Medicare Advantage (Part C)

• Premium: Varies by plan; many offer $0 premium (average about $17/month)
• Maximum Out-of-Pocket Limit: Cannot exceed $9,350 for in-network services in 2025

Help Paying for Medicare

Several programs can help with Medicare costs for those with limited income and resources:

Medicare Savings Programs (MSPs)

Administered by states to help cover Medicare costs:

• Qualified Medicare Beneficiary (QMB): Covers Part A and B premiums, deductibles, and coinsurance
• Specified Low-Income Medicare Beneficiary (SLMB): Covers Part B premiums only
• Qualifying Individual (QI): Covers Part B premiums only
• Qualified Disabled and Working Individuals (QDWI): Covers Part A premiums only

Apply through your state’s Medicaid agency.

Extra Help (Low-Income Subsidy – LIS)

Helps pay Part D costs, potentially saving thousands per year.

You automatically qualify if you receive full Medicaid coverage, assistance from an MSP, or SSI benefits.

Apply through the Social Security Administration:

• Online at SSA.gov
• By phone at 1-800-772-1213
• In person at a local Social Security office

Applying for both MSPs and Extra Help is highly recommended for anyone who might qualify.

Our articles make government information more accessible. Please consult a qualified professional for financial, legal, or health advice specific to your circumstances.