Can you start Medicare Part B anytime?

You cannot be denied Medicare Part B based on your health or medical history if you meet the basic eligibility rules.

Basic Eligibility for Part B

• Age: You must be 65 or older (or qualify early due to a disability or specific health condition like End-Stage Renal Disease).
• Residency: You must be a U.S. resident.
• Citizenship/Status: You must be a U.S. citizen or a lawfully admitted permanent resident who has lived in the U.S. continuously for five years.

When Enrollment Can Be Delayed or Rejected

While you cannot be denied for health reasons, your enrollment can be delayed or rejected if you apply outside an allowed Enrollment Period. You can only sign up during:

• Initial Enrollment Period: The 7-month window around your 65th birthday.
• General Enrollment Period: From January 1 to March 31 each year (which may result in a late penalty).
• Special Enrollment Period: If you delayed enrollment because you had group health coverage through an active job.

(Note: Private supplemental insurance—known as Medigap—can deny you based on health history if you apply outside your initial open enrollment window, but Original Medicare Part B itself cannot.)

Original Medicare (Parts A and B) does not cover routine dental care, routine vision care, hearing aids, long-term custodial care, and health care received overseas.

Major Uncovered Services in 2026

• Most dental care: Original Medicare does not pay for routine cleanings, checkups, fillings, tooth extractions, root canals, or dentures.
• Routine vision care: Regular eye exams, eyeglasses, and contact lenses are excluded, though treatments for medical eye conditions like cataracts or glaucoma are covered.
• Hearing aids: Original Medicare does not cover hearing aids or routine exams used to fit them.
• Long-term care: Extended nursing home care or custodial care (help with daily personal activities like bathing or dressing) is not covered outside of limited short-term skilled nursing rehabilitation.
• Overseas coverage: Medical care received outside of the United States and its territories is generally excluded, with rare exceptions like emergencies on cruise ships close to a U.S. port.

The Medicare Part B late enrollment penalty adds 10% to your monthly premium for every full 12-month period you delayed signing up without qualifying coverage, as outlined by the Official Medicare Avoid Penalties Guide.

How the Penalty Works

• Cost Surcharge: Your standard monthly premium increases by 10% for each full 12-month period of delay. Waiting 24 months means a 20% penalty. Partial 12-month periods do not count.
• Duration: You pay this extra amount for life (as long as you have Part B), and the penalty amount rises each year if the base standard Part B premium goes up.
• Calculation Basis: The penalty is calculated using the standard base premium (which is $202.90 in 2026) rather than any reduced or income-adjusted premium you might personally pay.

How to Avoid the Penalty

• Initial Enrollment Period (IEP): Sign up during the 7-month window that starts 3 months before the month you turn 65.
• Special Enrollment Period (SEP): You can delay Part B without a penalty if you or your spouse are actively working and have qualifying health coverage through an employer with 20 or more employees.
• Non-Qualifying Coverage: Plans like COBRA and retiree health coverage do not count as active employer coverage to exempt you from the Part B penalty.

The "worst" Medicare Advantage plans are generally identified by low federal star ratings (fewer than 3 stars), high out-of-pocket maximums, narrow local provider networks, and a heavy reliance on prior authorization requirements that delay or deny care.

Instead of a single nationwide "worst" company, low-performing options change by region and year. You can spot poorly rated or risky plans by watching for specific warning signs.

Red Flags of Low-Quality Plans

• Low Star Ratings: The Centers for Medicare & Medicaid Services (CMS) rate plans from 1 to 5 stars. Plans with 3 stars or fewer have below-average quality, customer service, and care outcomes.
• High Out-of-Pocket Limits: Some plans push the in-network medical out-of-pocket limit up toward the federal maximum ($9,250 or higher), meaning a severe medical year could cost you significantly more.
• Strict Prior Authorization: Low-tier private plans frequently require pre-approval for routine specialist visits, MRIs, or certain drugs, which often leads to delayed treatments.
• Restricted Local Networks: HMO plans that force you to get primary care referrals before seeing a specialist, or plans with very few participating local doctors and hospitals.
• Unstable Benefits: Plans that frequently drop participating doctors, alter drug formularies (covered medications), or drastically change co-pays from one year to the next.

How to Check Your Plan's Rating

You can evaluate specific regional offerings using the official Medicare Plan Finder tool to review current star ratings, estimated annual costs, and network rules before enrolling or renewing.

Medicare Part B is optional legally, but it is practically necessary for most people to avoid massive out-of-pocket medical bills and lifetime late penalties.

✅ When You Need Part B

• No other primary insurance: Covers 80% of outpatient care, doctor visits, and surgeries.
• Wanting supplemental coverage: Required to buy a Medigap plan or join Medicare Advantage.
• Specific military/retiree benefits: Mandatory if you use TRICARE For Life.

🗓 When You Can Delay Part B

• Current active employment: Working and covered by an employer plan with 20+ employees.
• Spouse's active employment: Covered by a working spouse's large employer plan.
• Penalty protection: Creditable coverage lets you delay enrollment without late fees.

⚠️ Hidden Risks & Penalties

• No out-of-pocket cap: Original Medicare alone leaves you exposed to unlimited 20% coinsurance.
• COBRA and VA trap: Neither counts as active employer coverage to waive Part B late penalties.
• Permanent late fee: Adds a lifelong 10% penalty to your monthly premium for every year delayed.