Why would someone have Medicare Part B only?

Someone might have only Medicare Part B because they do not qualify for premium-free Medicare Part A.

Lack of Work Credits

• Insufficient work history: A person qualifies for premium-free Part A only if they or their spouse worked and paid Medicare taxes for at least 10 years (or 40 work credits).
• Immigrants or non-citizens: Individuals who moved to the U.S. later in life or have a limited work history in the country may not earn enough credits for free Part A.
• Choosing Part B alone: If Part A requires a high monthly premium that a person cannot afford or chooses not to pay, they are still allowed to enroll in Medicare Part B by itself once they turn 65 and meet residency requirements.

A person can have Medicare Part B without Part A if they lack the required 10 years of U.S. work history for free Part A and choose not to pay Part A's expensive monthly premium, or if they intentionally delay Part A.

Ineligible for Free Part A

• Lacking Work History: You get Part A without a monthly premium if you or your spouse worked and paid Medicare taxes for at least 10 years (40 quarters).
• Choosing Not to Buy It: If you do not have that work history, you must pay a high monthly premium to buy Part A. Some people choose to buy only Part B (medical insurance for doctor visits) and skip Part A (hospital insurance) to save money, as explained by Medicare Interactive. (Note: You are allowed to sign up for Part B without buying Part A if you meet age and residency rules).

Delaying Part A

• Active Employer Coverage: Some people delay signing up for Part A when they turn 65 because they or their spouse are still working and have health insurance through a current employer.
• Avoiding Coordination Hassles: If a person has strong primary health insurance from an active job, they might delay Part A to avoid complicated rules about which insurance pays first, according to guidance from Medicare Resources.

If you only have Medicare Part A and Part B (called Original Medicare), the government pays for about 80% of your approved medical and hospital costs, but you must pay the remaining 20% out of your own pocket with no yearly limit.

Most users on Reddit agree that relying solely on Parts A and B leaves you financially vulnerable to high, uncapped medical bills during a major illness or injury.

What is Covered

• Part A (Hospital Insurance): Covers inpatient hospital stays, care in a skilled nursing facility, hospice, and some home health care.
• Part B (Medical Insurance): Covers doctor visits, outpatient care, medical supplies, and preventive services.

What is Missing or Uncapped

• No Out-of-Pocket Maximum: Original Medicare does not cap how much you can spend in a year. If you have a severe health issue, that 20% coinsurance can add up to thousands of dollars.
• No Prescription Drug Coverage: Parts A and B do not cover most outpatient prescription drugs. You must buy a separate Part D plan or face a late penalty.
• No Dental, Vision, or Hearing: Routine dental care, eye exams, glasses, and hearing aids are not covered.

Common Solutions

To protect themselves from high costs, most people add extra coverage:

• Medigap (Medicare Supplement): A private insurance policy that pays the 20% coinsurance and deductibles left by Parts A and B.
• Medicare Advantage (Part C): An all-in-one private plan that replaces Original Medicare and often includes drug, vision, dental, and out-of-pocket limits.

Someone might opt out or delay enrolling in Medicare Part B to avoid paying monthly premiums when they already have other qualifying health coverage.

Main Reasons to Opt Out or Delay

• Active Employer Coverage: People who keep working past age 65 and have health insurance through a current employer (with 20 or more employees) often delay Part B because they already have primary coverage.
• Spouse's Active Employer Plan: Someone covered by an active group health plan through a working spouse's job may decline Part B to avoid paying duplicate premiums.
• Avoiding Monthly Costs: The standard Part B premium costs over $200 a month in 2026, and high-income earners pay even more due to extra income-based surcharges (IRMAA).
• Veterans Affairs (VA) Benefits: Some veterans who receive all their medical care through the U.S. Department of Veterans Affairs choose not to pay for Part B, though doing so requires careful consideration of how VA and non-VA care interact.

Important Risks

• No Penalty with Creditable Coverage: You can safely skip Part B without penalties if you have active, qualifying (creditable) employer insurance.
• Late Penalties Without Coverage: If you opt out without qualifying group coverage and sign up later, you face a permanent 10% late-enrollment penalty for every 12-month period you waited.
• Retiree Plans and COBRA: Retiree health plans and COBRA do not count as active work coverage, meaning you cannot safely delay Part B past 65 while using them.

You were automatically enrolled in Medicare Part B because you were already collecting Social Security or disability benefits when you reached the qualifying milestone.

Reasons for Automatic Enrollment

• Receiving Social Security Retirement: You started getting Social Security retirement benefits at least four months before turning age 65.
• Receiving Disability Benefits: You received Social Security Disability Insurance (SSDI) benefits for 24 consecutive months.
• Special Health Conditions: You were diagnosed with Amyotrophic Lateral Sclerosis (ALS / Lou Gehrig's disease), which triggers immediate enrollment.

What This Means For You

• Monthly Premium: Medicare Part B requires a monthly premium, which is typically deducted directly from your Social Security payment.
• If You Want to Decline: Part B is voluntary. If you have other coverage (such as an employer group health plan through an active job) and wish to decline Part B, you can follow the instructions on the back of your red, white, and blue Medicare card, sign it, and mail it back. You can learn more about managing this process through Understanding Medicare Automatic Enrollment or read the AARP Automatic Medicare Enrollment Guide.