Should I get Medicare Part B if I have other insurance?

Editorial team InsuredAndMore.com Published on November 3, 2026

You generally do not need Medicare Part B if you have active health insurance from a current employer with 20 or more employees.

When You Can Delay Part B

Current Employer Coverage (20+ Employees): If you or your spouse are actively working and have group health insurance from a company with 20 or more workers, that plan pays first (primary), and Medicare pays second. You can delay Part B without a late penalty.
Special Enrollment Period: When that active employment or coverage ends, you get an 8-month window to sign up for Part B without paying a penalty.

When You Must Enroll in Part B

Small Employers (Fewer than 20 Employees): If your insurance is through a company with fewer than 20 employees, Medicare pays first. You must sign up for Part B when you first become eligible at age 65 to avoid high out-of-pocket costs and late penalties.
COBRA or Retiree Coverage: COBRA and retiree health plans do not count as active employment coverage. You must sign up for Part B during your Initial Enrollment Period when turning 65 to avoid lifetime penalties.
Marketplace Plans: Individual plans bought through the Health Insurance Marketplace do not let you delay Part B penalty-free.

Do I need Medicare Part B if I already have insurance?

Whether you need Medicare Part B depends on the type of insurance you have and the size of your employer.

When You Can Delay Part B Without Penalty

You can usually delay signing up for Medicare Part B and avoid late fees if you have current work-based insurance from a large employer:

Large Employer: Your or your spouse's active employer has 20 or more employees.
Union or Group Plan: You are actively working and covered by a qualifying group health plan.
When this active employment coverage ends, you get an 8-month UnitedHealthcare Special Enrollment Period to sign up for Part B without a penalty.

When You MUST Enroll in Part B

You need to enroll in Part B when you turn 65, even if you have other coverage, in these situations:

Small Employer: You work for a company with fewer than 20 employees (Medicare becomes your primary insurance).
Retiree Coverage: You have health coverage from a former employer or union.
COBRA: You are on COBRA continuation coverage.
Individual or Marketplace Plan: You have a private plan through the Health Insurance Marketplace.
Other Programs: You have VA health coverage, TRICARE (non-active duty situations vary, but check specific rules), or individual policies.

Failing to sign up when required can result in a permanent 10% late enrollment penalty added to your monthly Part B premium for every year you delayed. You can learn more about how different coverages interact through the Official Medicare Coordination of Benefits.

Is it better to have Medicare as primary or secondary insurance?

You cannot usually choose whether Medicare is primary or secondary; federal coordination of benefits rules set the order automatically based on your employment status, company size, or other coverage.

How the Payment Order Works

Primary Payer: Pays first up to its coverage limits.
Secondary Payer: Pays remaining costs (like deductibles or copays) only if it covers that service, though it may not pay the full leftover amount.
Having a secondary insurance is generally beneficial because it helps cover the gaps left by the primary insurance.

When Medicare is Primary vs. Secondary

Federal rules dictate which plan pays first:

Large Employer Plan (20+ employees): If you or a spouse are actively working and covered by a large employer group health plan, the employer plan is primary and Medicare is secondary.
Small Employer Plan (Fewer than 20 employees): If you are working and covered by a small business, Medicare is primary and the employer plan is secondary.
Retiree Coverage: If you have health insurance from a former employer or union, Medicare is primary and the retiree plan is secondary.
COBRA: If you have COBRA continuation coverage and enroll in Medicare, Medicare is primary and COBRA is secondary.

Who does not have to pay Medicare Part B premiums?

Almost everyone who enrolls in Medicare Part B must pay a monthly premium, as there is no automatic "free" Part B option based on work history. However, you do not have to pay these costs out of pocket if you qualify for specific financial assistance programs or insurance plan benefits.

As noted by CBS News, most seniors cannot completely avoid these premiums unless they qualify for specific relief programs.

Low-Income Assistance Programs

Medicaid: If your income and assets are very low, your state’s Medicaid program may pay your monthly Part B premium for you.
Medicare Savings Programs (MSPs): State programs like the Qualified Medicare Beneficiary (QMB) program help pay Part B premiums, and sometimes deductibles and co-pays, for qualifying low-income individuals.

Insurance and Employer Benefits

Medicare Advantage "Giveback" Plans: Some private Medicare Advantage plans offer a Part B premium reduction benefit (known as a "giveback") that covers part or all of your monthly Part B premium.
Employer or Union Coverage: If you or your spouse are still working, or have retiree/union benefits, your employer or union may fully reimburse you for your Part B premium cost.

Can I opt out of Medicare Part B if I have other insurance?

Yes, you can opt out or cancel Medicare Part B if you have other health insurance, but whether you should depends on the type of insurance you have and your employer's size.

When You Can Delay or Drop Part B Without Penalty

Active Employer Coverage: If you or your spouse are actively working and have health insurance through an employer with 20 or more employees, that plan acts as the primary payer. You can delay or drop Part B without a late enrollment penalty.
Special Enrollment Period: When that active employment or coverage ends, you get an 8-month window to sign up for Part B without paying late penalties.

Risks to Consider

Small Employers: If your employer has fewer than 20 employees, Medicare is usually the primary payer. If you drop Part B here, your other insurance may not cover your medical bills, and you could face penalties.
COBRA and Retiree Coverage: Neither COBRA nor retiree health plans count as active employment coverage. Dropping Part B while on COBRA or retiree insurance can trigger permanent late penalties and gaps in coverage.
VA Benefits: Veterans affairs (VA) coverage does not exempt you from Part B late enrollment penalties if you drop coverage without active employer insurance.

How to Cancel Part B

Contact Social Security: Call the Social Security Administration at 1-800-772-1213 to review the risks or schedule an interview.
Complete the Form: Fill out Form CMS-1763 to request the termination of your medical insurance.
Submit: Mail or fax the signed form to your local Social Security office and return your Medicare card as instructed. Opinions on Facebook are mixed regarding how smooth the disenrollment process feels, so checking details with an agent first is recommended.

Do I Need Medicare Part B if I Have FEHB?

9 related questions found

Why do people opt out of Medicare Part B?

People opt out or delay enrollment in Medicare Part B primarily to avoid monthly premium costs when they already have active, qualifying health insurance from an employer.

Main Reasons for Opting Out

Active Employer Coverage: Individuals (or their spouses) who continue working past age 65 often keep their employer-sponsored health plan if the company has 20 or more employees. If this coverage is considered "creditable," they can delay Part B without facing late penalties.
High Premium Costs and IRMAA: High-income earners pay an Income-Related Monthly Adjustment Amount (IRMAA), which significantly increases their standard Part B monthly premium. Some retirees opt out or evaluate alternative private plans if the extra cost outweighs the perceived value.
Alternative Government Plans: Some federal retirees with robust coverage through programs like the Federal Employees Health Benefits (FEHB) program choose to delay Part B to preserve their immediate cash flow.

Risks of Opting Out

Permanent Late Penalties: Dropping or delaying Part B without valid, active employer coverage results in a permanent 10% late enrollment penalty for every 12 months you go without coverage.
Loss of Supplemental Options: Without Part B, you cannot enroll in Medigap (Medicare Supplement) or standard Medicare Advantage plans.

Do federal retirees really need Medicare Part B?

For most civilian federal retirees with Federal Employees Health Benefits (FEHB), Medicare Part B is optional, not legally required, but postal service retirees under PSHB rules generally face mandatory enrollment.

📊 Comparing Your Options

Feature	❌ Skipping Part B (FEHB Only)	✅ Enrolling in Part B (Medicare + FEHB)
Primary Payer	FEHB pays first for all claims.	Medicare pays first; FEHB wraps around.
Monthly Cost	Only your standard FEHB premium.	FEHB premium + monthly Part B premium.
Deductibles & Copays	You pay standard plan cost-sharing.	Many FEHB plans waive deductibles/copays entirely.
Out-of-Network	Limited or no coverage on certain plans (e.g., BCBS Basic).	Access to any doctor nationwide who accepts Medicare.

💡 Why Some Retirees Choose Part B

Lower out-of-pocket costs: Coordination eliminates copays and deductibles on many plans.
Premium reimbursements: Specific FEHB plans offer partial Part B premium rebates.
Wider provider access: Out-of-network restrictions disappear under Medicare coordination.

⚠️ Why Some Retirees Skip Part B

Extra monthly costs: Part B adds an independent, income-adjusted monthly premium per person.
FEHB is already robust: Comprehensive coverage makes the extra premium redundant for healthy retirees.
No late penalty if ignored: Civilian retirees who never elect Part B face no penalties as long as they stick solely to FEHB.

What are the biggest mistakes people make with Medicare?

The biggest mistake people make with Medicare is missing enrollment windows, which can lead to permanent financial penalties and coverage gaps.

Timing and Enrollment Mistakes

Missing Deadlines: Failing to sign up during your Initial Enrollment Period (IEP) around age 65 triggers lifelong financial penalties for Part B and Part D.
Misjudging Work Coverage: Assuming you can delay enrollment while working past 65 without checking if your employer plan is "creditable coverage" (plans with fewer than 20 employees often require Medicare to go first).
Missing the Medigap Window: Waiting past your 6-month Medigap Open Enrollment Period (which starts when you turn 65 and enroll in Part B) means you may have to pass medical underwriting to get a supplemental plan.

Plan Choice and Cost Mistakes

Focusing Only on Premiums: Choosing a plan with a low or $0 monthly premium without checking deductibles, copays, or maximum out-of-pocket costs.
Ignoring Annual Changes: Not reviewing your plan’s Annual Notice of Change (ANOC) or skipping the Annual Enrollment Period, which leads to surprise costs as drug formularies and doctor networks shift yearly.
Assuming Doctors are In-Network: Failing to verify if your preferred physicians and hospitals accept your specific Medicare Advantage or Part D network.
Thinking Medicare is Free: Forgetting that Original Medicare has monthly premiums, deductibles, and coinsurance, and does not cover routine dental, vision, or hearing care.

What is the best secondary insurance to have with Medicare?

The best secondary insurance to pair with Original Medicare is a standardized Medicare Supplement Insurance (Medigap) policy, with Plan G and Plan N widely considered the top choices.

Secondary insurance acts as a safety net to pay the out-of-pocket costs—like coinsurance, copays, and deductibles—that Original Medicare (Parts A and B) leaves behind.

Top Medigap Plan Options

Plan G: This is the most comprehensive choice available for new enrollees. It covers 100% of all out-of-pocket costs approved by Medicare after you pay the annual Part B deductible.
Plan N: This is a lower-cost alternative to Plan G. It covers most out-of-pocket expenses, but you pay the Part B deductible, small copays for doctor visits (up to $20), and some emergency room visits.
High-Deductible Plan G: This option offers very low monthly premiums. However, you must pay out-of-pocket medical costs up to a higher yearly deductible before the secondary insurance starts paying.

Key Benefits of Medigap as Secondary Insurance

No Networks: You can see any doctor or visit any hospital nationwide as long as they accept Medicare.
No Referrals: You do not need a referral to see a specialist.
Guaranteed Renewable: Your coverage cannot be canceled or changed due to health issues as long as you pay your monthly premium.
Standardized Benefits: A Plan G or Plan N offers the exact same core medical benefits regardless of which private insurance company sells it. Price and customer service are the only differences. Top providers include AARP/UnitedHealthcare, Mutual of Omaha, and State Farm.

(Note: Medigap policies do not include prescription drug coverage, which requires a separate Part D plan, nor do they cover routine dental, vision, or hearing care.)

What is the downside of Medicare Part C?

The primary downside of Medicare Part C (Medicare Advantage) is that plans use restrictive networks and require prior approval for treatments, which can limit your choice of doctors and delay medical care.

Key Drawbacks of Medicare Part C

Limited Provider Networks: You must generally see doctors and hospitals within the plan’s local network. Seeing out-of-network providers can cost much more or may not be covered at all.
Prior Authorization Requirements: You often need advance approval from the insurance company before getting certain tests, specialist visits, or treatments. This process can cause frustrating delays or denials of care.
Geographic Restrictions: Routine coverage is usually restricted to your local area, meaning these plans are often poorly suited for people who travel frequently or split time in another state.
Annual Plan Changes: Benefits, copays, and provider networks can change from year to year, requiring you to carefully review your plan every annual enrollment period.
No Medigap Compatibility: You cannot use a Medicare Supplement (Medigap) policy to cover out-of-pocket costs while enrolled in a Medicare Advantage plan.