Mount Sinai South Nassau and Medicare in Freeport: Which Plans Cover Your South Shore Doctors in 2026

By Paul Barrett, CMIP | The Modern Medicare Agency | Melville, NY 18+ years Medicare-exclusive experience | Licensed in 34 states | 40+ carriers Last updated: June 2026

If you live in Freeport and your doctors are at Mount Sinai South Nassau, stop what you’re doing and read this first.

In 2026, one of the most significant hospital-insurance disputes in New York’s recent memory played out on your doorstep — and if you’re on certain Medicare Advantage plans, it’s still unresolved for you right now. Your neighbors in Valley Stream found out in January that their longtime Mount Sinai doctors were suddenly out-of-network. Some had surgeries scheduled. Some were in active treatment. Nobody warned them until it was almost too late.

That’s what this article is for.

I’ve been helping South Shore Nassau County residents navigate Medicare from my Melville office for 18 years. This isn’t a generic guide about Medicare Advantage. This is the specific, local, real-time intelligence you need to know whether your Medicare plan still opens the doors at One Healthy Way in Oceanside — or closes them.

Why Mount Sinai South Nassau Is Not Optional for South Shore Residents

Let’s start here, because this isn’t just about one hospital.

Mount Sinai South Nassau in Oceanside is the only Level II Trauma Center on Nassau County’s South Shore — verified by the American College of Surgeons. It operates the only stroke center and the only freestanding 9-1-1 receiving Emergency Department in the area. It has 455 beds, more than 900 physicians, and approximately 3,500 employees serving communities from the Rockaways to Massapequa.

In March 2025, they completed a $50 million, five-year renovation that doubled the size of the Emergency Department — from 15,000 to 30,000 square feet, with 54 private exam rooms, centralized nursing stations, and an updated trauma unit with an adjoining radiology bay. The capacity to see approximately 75,000 patients annually. They’re in the middle of a 100,000-square-foot expansion that will add four floors, 40 new ICU beds, and nine operating rooms, with an estimated completion of September 2026.

This is not a community hospital people visit for minor issues and then move on from. For Freeport, Oceanside, Rockville Centre, Valley Stream, Lynbrook, Baldwin, Merrick, and the surrounding South Shore communities, Mount Sinai South Nassau is where people go when things get serious — cardiac events, cancer treatment, strokes, major surgery, trauma.

It earned an ‘A’ for Patient Safety from The Leapfrog Group in the 2026 spring cycle. It received a 2026 Patient Safety Excellence Award from Healthgrades. It has been named to Healthgrades’ 100 Best Hospitals for Coronary Intervention for three consecutive years. It earned 10 U.S. News & World Report “high performing” ratings for conditions including heart attack, heart failure, diabetes, colon surgery, and leukemia/lymphoma/myeloma.

The reason I’m telling you all this is simple: a Medicare Advantage plan that doesn’t cover Mount Sinai South Nassau isn’t a real option for most Freeport-area residents. It’s a liability disguised as coverage.

What Happened Between Anthem and Mount Sinai — The Full Story

This is the most important thing that happened in South Shore Medicare in 2026, and most people heard about it through a letter or a worried conversation with their doctor’s office. Here’s the complete picture.

The Background

Anthem Blue Cross and Blue Shield (formerly known locally as Empire BCBS, now rebranded under Elevance Health) and Mount Sinai Health System had a contract that expired December 31, 2025. Negotiations began in spring 2025. Both sides failed to reach a new agreement.

What Mount Sinai said: “We cannot — and will not — subsidize a for-profit insurer’s margins.” Mount Sinai argued the insurer owed more than $450 million in unpaid claims and was offering reimbursement rates that fell too far below what peer academic medical centers receive.

What Anthem said: Mount Sinai was demanding a 50% rate increase by 2028, “far outpacing inflation,” and seeking provisions that would “drive up unnecessary spending.” Mount Sinai disputed this characterization publicly, stating it sought single-digit annual increases over three years and that Anthem was paying it up to 35% less than comparable New York health systems.

Both sides put their position in writing and went public with it. Neither blinked.

The Timeline

  • January 1, 2026: Mount Sinai physicians — all 9,000 of them across New York City and Long Island — exited the Anthem network. For Medicare Advantage members specifically, this meant losing in-network access to their doctors immediately.
  • March 4, 2026: Mount Sinai hospitals and facilities — including Mount Sinai South Nassau in Oceanside — exited the Anthem commercial network. This is the date explicitly named in a New York State Civil Service document listing the affected facilities.
  • April 13, 2026: Mount Sinai and Anthem reached a new three-year agreement that restored in-network access for most Anthem members.

The critical exception: The April 2026 agreement explicitly and specifically does not cover Anthem Medicare Advantage plans. Mount Sinai’s own statement confirmed this directly: “Please note that this agreement does not include Anthem Medicare Advantage or Anthem Individual Marketplace plans.”

This means that as of today — June 2026 — Anthem Medicare Advantage members still do not have in-network access to Mount Sinai South Nassau. The commercial dispute is resolved. The Medicare Advantage dispute is not.

Sources: choosemountsinai.org (Mount Sinai official communications); keepmountsinai.org (April 2026 resolution announcement); Fierce Healthcare (April 14, 2026); News 12 Long Island; New York State Civil Service (cs.ny.gov), Anthem Blue Cross Mount Sinai update

Who This Affects in Freeport Right Now

If you are currently enrolled in any Anthem Blue Cross Blue Shield Medicare Advantage plan in Nassau County, you do not have in-network access to Mount Sinai South Nassau.

This includes:

  • Anthem Medicare Advantage 2 HMO-POS (the 5-star rated plan)
  • Any other Anthem Medicare Advantage product in Nassau County

In-network benefits at Mount Sinai South Nassau are not available. Emergency services are covered by law at in-network rates — emergency care is always available regardless of network status. But for everything else — your cardiologist, your oncologist, your orthopedist, your scheduled procedures, your follow-up appointments — you are paying out-of-network rates or finding a different facility.

If you are an Anthem Medicare Advantage member and received care at Mount Sinai South Nassau between January 1 and April 13, 2026: contact Anthem’s member services and ask specifically whether your claims are being reprocessed. The April agreement may affect retroactive claim processing, but Anthem has not publicly confirmed blanket retroactive reprocessing for Medicare Advantage claims.

The Plans That Currently Cover Mount Sinai South Nassau for Medicare

Here is the honest, sourced status of every major Medicare Advantage carrier’s relationship with Mount Sinai South Nassau:

✅ AETNA — In-Network and Strong

Aetna maintains an active network relationship with Mount Sinai South Nassau for Medicare Advantage. An official Mount Sinai Health Partners document explicitly lists Aetna Commercial and Medicare Advantage plans and identifies Mount Sinai South Nassau as a preferred facility. With over 15,740 Nassau County enrollees in the Aetna Medicare Elite PPO alone, Aetna is the most enrolled Medicare Advantage plan in Nassau County — and its South Shore network relationships are part of why.

Aetna’s PPO structure is particularly valuable for South Shore residents: you can see specialists at Mount Sinai South Nassau, Catholic Health’s Mercy Medical in Uniondale, and NYU Langone Hospital on Long Island — all without a referral. For anyone whose care spans multiple South Shore systems, this flexibility is genuinely important.

Always verify your specific physician. While Aetna’s relationship with Mount Sinai South Nassau is confirmed, some individual physicians may bill separately and may not participate in every Aetna plan sub-type. Ask your doctor: “Do you participate in the Aetna Medicare Elite PPO for 2026?” — not just “Do you take Aetna?”

✅ UNITEDHEALTHCARE — In-Network (with a specific caveat)

Standard UHC/Oxford Medicare Advantage plans are in-network with Mount Sinai South Nassau. However, there is one exception every UHC member needs to know: Mount Sinai explicitly does not participate with the UHC Community Plan. This is stated directly on choosemountsinai.org’s accepted insurance plans page.

If you are on any UHC Medicare Advantage plan and see Mount Sinai South Nassau providers, confirm your specific plan is not the Community Plan product. The question to ask: “Does Mount Sinai South Nassau participate in my specific UHC plan — [plan name]?” Not just “Do you take UnitedHealthcare?”

✅ VNS HEALTH — In-Network

VNS Health (formerly Visiting Nurse Service of New York) reached a new agreement with the full Mount Sinai Health System to continue participating in-network through 2026. This is confirmed directly on the choosemountsinai.org official communications page. VNS Health serves a meaningful segment of Nassau’s dual-eligible and lower-income population and the Mount Sinai relationship is intact.

✅ HEALTHFIRST — In-Network (verify individual providers)

Healthfirst maintains a general network relationship with Mount Sinai providers. However, Healthfirst’s network strength on Long Island is considerably more limited than in the five boroughs. Freeport residents should verify each specific physician before enrolling. The question is not whether Healthfirst “covers” Mount Sinai South Nassau in general — it’s whether your particular cardiologist or oncologist participates in the specific Healthfirst plan you’re considering.

⚠️ ANTHEM BLUE CROSS BLUE SHIELD — NOT In-Network for Medicare Advantage

As detailed above: Anthem Medicare Advantage plans are explicitly excluded from the April 2026 Mount Sinai agreement. Not in-network. Emergency services remain covered by federal law. Everything else is out-of-network.

⚠️ WELLCARE — Mount Sinai South Nassau Generally In-Network, But Northwell Is Not

Wellcare’s relationship with Mount Sinai South Nassau is not publicly in dispute as of this writing. However, Wellcare chose not to renew its contract with Northwell Health — the other major health system serving Nassau County — effective July 1, 2026. Some Freeport residents use both South Shore (Mount Sinai South Nassau) and North Shore (Northwell) providers. If you have any Northwell specialists — particularly at Long Island Jewish Medical Center in New Hyde Park — Wellcare’s Northwell exit matters to you directly.

⚠️ HEALTHSPRING (formerly Cigna Medicare) — Mount Sinai South Nassau Generally In-Network, But Northwell Is Not

Same situation as Wellcare on the Northwell side. HealthSpring terminated its relationship with Northwell effective December 31, 2025, covering all Northwell hospitals, physician groups, and ancillary facilities. If you have care split between South Shore and Northwell facilities, verify both.

The Quick Reference Table

Carrier

Mount Sinai South Nassau (MA)

Key Note

Aetna

✅ In-Network

Most enrolled plan in Nassau; PPO offers broadest South Shore flexibility

UnitedHealthcare

✅ In-Network (standard plans)

❌ UHC Community Plan NOT accepted — verify your specific plan name

VNS Health

✅ In-Network

New 2026 agreement confirmed by Mount Sinai

Healthfirst

✅ Generally (verify each provider)

Stronger in boroughs — verify each Long Island physician

Anthem BCBS

❌ NOT In-Network (MA)

Apr 2026 agreement excludes Medicare Advantage — unresolved

Wellcare

✅ Mount Sinai South Nassau

❌ Northwell out-of-network as of July 1, 2026

HealthSpring

✅ Mount Sinai South Nassau

❌ Northwell terminated Dec 31, 2025

Medigap (any plan)

✅ Always covered

Works wherever Medicare is accepted — immune to all network disputes

Information as of June 2026. Network agreements are subject to change — always verify current status before scheduling non-emergency care.

The Broader Picture: Why This Keeps Happening

The Anthem/Mount Sinai standoff wasn’t a freak occurrence. It’s part of a nationwide pattern that is accelerating.

Becker’s Hospital Review documented 23 major health systems dropping Medicare Advantage plans across the country in 2026 alone. New York-Presbyterian and UnitedHealthcare nearly went out of network in June 2026 without a last-minute agreement. Northwell lost Wellcare and HealthSpring. Fidelis Care and Northwell went through a standoff with a July 15 deadline.

The underlying issue is always the same: Medicare Advantage plans pay hospitals significantly less than traditional Medicare, and the gap is widening. Hospitals reach a point where they look at what they’re paid versus what care actually costs, and the math stops working.

Here’s what that means for you as a consumer: a plan that covers your hospital today may not cover it next January. Network stability is not guaranteed. And for people on fixed incomes with serious health conditions and established relationships with specific doctors, that instability has real, serious consequences.

The Option That Is Immune to All of This

I want to be direct about something, because it’s what I’d tell a family member.

Every hospital-insurance dispute you’ve read about in this article — Anthem and Mount Sinai, Wellcare and Northwell, HealthSpring and Northwell, Fidelis and Northwell — affects only Medicare Advantage members.

Medigap members are entirely unaffected by all of them.

Here’s why: A Medicare Supplement (Medigap) plan works alongside Original Medicare, not as a replacement for it. It covers the gaps — the 20% coinsurance, the hospital deductibles — that Original Medicare leaves behind. Because your coverage is through Original Medicare, any provider in the country who accepts Medicare accepts your Medigap plan.

Mount Sinai South Nassau accepts Original Medicare. Therefore, with any Medigap plan, Mount Sinai South Nassau is covered. If Anthem and Mount Sinai go to war again next January, it doesn’t affect you. If some other carrier drops out of the Mount Sinai network next AEP, it doesn’t affect you. The protection is structural, not dependent on a contract that’s up for renegotiation every few years.

The trade-off is real: Medigap on Long Island is expensive. Plan G through UHC — the lowest-priced carrier — runs $372.50/month for 2026. Add the $283 Part B deductible and a Part D plan, and your minimum annual commitment exceeds $5,000 before you use a medical service.

But for someone managing cancer treatment at Mount Sinai South Nassau’s Feil Cancer Center, or recovering from cardiac intervention after a procedure at their newly expanded ER, or seeing a specialist who has treated them for years — the math may look very different when you weigh the monthly premium against the uncertainty of Medicare Advantage network stability in 2026.

New York also gives you a right most Americans don’t have: you can switch from Medicare Advantage to Medigap at any time of year, with no medical underwriting, regardless of your health. That option is open to you today.

For a full breakdown of what Medigap actually costs on Long Island and which carriers are genuinely available, see our Medicare Supplement Plans in Freeport, NY: 2026 Rates and What NY’s Rules Mean for You.

What To Do Right Now If You're Affected

If you’re on an Anthem Medicare Advantage plan:

  1. Call Anthem’s member services at the number on your card and ask specifically: “Is Mount Sinai South Nassau in-network for my plan?” Get the answer in writing or note the date, time, and representative’s name.
  2. Call Mount Sinai South Nassau’s insurance department at (516) 632-3000 and ask whether your specific Anthem plan is currently accepted for non-emergency care.
  3. If you have upcoming procedures, appointments, or ongoing treatment — call my office at 631-358-5793 before that appointment. You may have options you don’t know about.
  4. You cannot currently make a mid-year plan change solely because Anthem doesn’t cover Mount Sinai Medicare Advantage — but your specific circumstances (active treatment, chronic condition, upcoming procedure) may qualify you for a Special Enrollment Period. Don’t assume. Call and ask.

If you’re considering a new Medicare Advantage plan and use Mount Sinai South Nassau:

Before you look at a single premium, give me the name of your doctor. I’ll run a live network check against every plan available in Nassau County. Not a general “does this carrier cover Mount Sinai” search — a specific check for your physician, your plan type, and your zip code. That’s the only check that actually matters.

If you’re currently on Medigap:

You’re protected from everything in this article. Original Medicare plus your supplement plan means Mount Sinai South Nassau — and any other Medicare-accepting facility in the country — is available to you. Review your Part D coverage annually, make sure your rates are still competitive, and call me if your premium has spiked.

Frequently Asked Questions

No. Anthem Medicare Advantage plans are explicitly excluded from the April 2026 agreement between Anthem and Mount Sinai Health System. Mount Sinai South Nassau — as part of the Mount Sinai Health System — is not in-network for Anthem Medicare Advantage as of June 2026. Emergency services remain covered at in-network rates by federal law. For all other care, Anthem Medicare Advantage members face out-of-network cost-sharing at Mount Sinai South Nassau.

Anthem and Mount Sinai failed to renew their contract by December 31, 2025. Mount Sinai physicians — approximately 9,000 across New York City and Long Island — left the Anthem network January 1, 2026. Mount Sinai hospitals, including South Nassau, exited March 4, 2026. A new three-year agreement was reached April 13, 2026 — but it explicitly excludes Medicare Advantage and Individual Marketplace plans. The dispute centered on reimbursement: Anthem claimed Mount Sinai sought a 50% rate increase by 2028, which Mount Sinai publicly disputed, stating it sought single-digit annual increases and that Anthem was paying it up to 35% below comparable New York health systems. Mount Sinai also stated Anthem owed over $450 million in unpaid claims for care already delivered.

Aetna Medicare Advantage plans maintain an active in-network relationship with Mount Sinai South Nassau. Standard UHC/Oxford Medicare Advantage plans (not the Community Plan) are in-network. VNS Health reached a new 2026 agreement with Mount Sinai. Healthfirst generally participates, but individual provider verification is essential given their thinner Long Island network.

Yes. Federal law requires Medicare Advantage plans to cover emergency services at in-network cost-sharing rates regardless of network status. If you have a genuine emergency, go to Mount Sinai South Nassau — your plan must cover it as in-network. The network dispute affects non-emergency scheduled care.

 Possibly. If your Anthem Medicare Advantage plan’s loss of Mount Sinai access constitutes a significant disruption to your ongoing care, you may qualify for a Special Enrollment Period. Eligibility depends on your specific situation — active treatment, chronic conditions, upcoming procedures all matter. Call me at 631-358-5793 and I’ll review your circumstances at no charge.

Yes — completely. Medigap plans work alongside Original Medicare, which means any provider who accepts Medicare accepts your coverage. Mount Sinai South Nassau accepts Original Medicare. Network disputes between carriers and hospitals don’t affect Medigap members. In New York, you can switch from Medicare Advantage to Medigap any time of year without medical underwriting. If network instability concerns you, that option is worth a serious conversation.

Mount Sinai South Nassau joined the Mount Sinai Health System in 2018 and is the system’s Long Island flagship hospital — the only Mount Sinai facility outside New York City. It’s fully integrated into the Mount Sinai Health System clinically, which means patients have access to the system’s broader specialist network and research resources. It also means that system-level contract disputes — like the Anthem situation — affect South Nassau as part of the system, not separately.

If your plan representative told you Mount Sinai South Nassau is in-network for your Anthem Medicare Advantage plan after April 13, 2026 — get that confirmation in writing, with a reference number. The April agreement specifically excluded Medicare Advantage. If there has been a separate, more recent agreement specifically covering Medicare Advantage that was not publicly announced as of this writing, Mount Sinai’s own website at choosemountsinai.org will reflect it. Check there directly for the most current status.

Ready for an Honest Conversation?

I serve Freeport, Oceanside, Rockville Centre, Valley Stream, Lynbrook, Baldwin, Merrick, and all of Nassau County’s South Shore from my office in Melville. If you’re worried about your Mount Sinai access, if you’re on an Anthem plan and trying to figure out your options, or if you’ve never had someone sit down and actually check your specific doctors against your specific plan — call me.

No scripts. No pressure. No disappearing after you enroll.

Just honest guidance from someone who has been doing this on the South Shore for 18 years and is still answering calls in February when questions come up.

Paul Barrett, CMIP The Modern Medicare Agency 📞 631-358-5793 ✉️ medicare@paulbinsurance.com 🌐 paulbinsurance.com 📍 445 Broad Hollow Rd, Melville, NY 11747

Serving Freeport and Nassau County’s South Shore since 2007

Related reading:

Primary sources:

Disclaimer: The Modern Medicare Agency is not connected with or endorsed by the United States government or the federal Medicare program. Network participation status reflects publicly available information as of June 2026 and is subject to change. Always verify your specific plan’s network status directly with your carrier and provider before scheduling non-emergency care. We do not offer every plan available in your area.

What Is Medicare Part B and What Does It Actually Cover?

The complete guide to Medicare’s medical insurance — every service it covers, exactly what it costs in 2026, how it works with group insurance and VA benefits, and the excess charges most people have never heard of until they get a surprise bill.

The Short Answer

Medicare Part B is medical insurance — it covers doctor visits, outpatient care, preventive services, durable medical equipment, and more. Unlike Part A, Part B is not premium-free for anyone: everyone pays a monthly premium (202.90in2026formostpeople),anannualdeductible(283), and 20% coinsurance on most covered services, with no yearly cap on that 20% under Original Medicare alone. Whether you need to enroll at 65, and whether delaying is safe, depends heavily on your employment status and your employer’s size — getting this wrong is one of the most consequential and permanent mistakes in all of Medicare.

Key Takeaways

  • Part B is never premium-free — everyone pays a monthly premium, and higher earners pay significantly more through IRMAA.
  • The 20% coinsurance under Original Medicare alone has no yearly cap — this is the single biggest financial risk in Medicare, and it’s the reason Medigap and Medicare Advantage exist.
  • Whether you can safely delay Part B without a penalty depends on your employer’s size: 20+ employees generally allows delay; fewer than 20 generally does not.
  • Missing your enrollment window triggers a permanent 10% penalty for every 12-month period you went without coverage.
  • Veterans can and generally should enroll in Part B even with VA benefits, since Medicare and VA coverage don’t coordinate — each only pays for care received within its own system.
  • “Excess charges” from non-participating providers can add up to 15% on top of what Medicare approves, and only some Medigap plans protect you from them.

What Part B Actually Covers

While Part A handles hospital room and board, Part B is the half of Original Medicare that covers medical care and most services delivered outside a hospital admission — doctor visits, outpatient procedures, and ongoing medical needs.

What’s covered

  • Doctor visits — primary care and specialists
  • Outpatient surgeries and procedures
  • Diagnostic lab work, X-rays, and MRIs
  • Emergency room visits
  • Ambulance services
  • Outpatient mental health care
  • Physical, occupational, and speech therapy
  • Chemotherapy and radiation received in an outpatient clinic
  • Durable Medical Equipment (DME) — wheelchairs, oxygen equipment, blood sugar monitors, walkers, and similar equipment
  • Ambulatory surgical center services

Preventive services: the part Medicare gets genuinely right

Most preventive services are covered at 100%, with no deductible and no copay, as long as your provider accepts Medicare assignment. This includes:

  • Your one-time “Welcome to Medicare” wellness visit, available within your first 12 months on Part B
  • Annual wellness visits after that
  • Flu shots and most other recommended vaccines
  • Mammograms
  • Colonoscopies and other cancer screenings
  • Diabetes and cardiovascular screenings
  • Many other screenings recommended by the U.S. Preventive Services Task Force

Paul’s Honest Take: This is one of the most underused parts of Medicare, full stop. I’ve had clients who paid for a private physical every year out of habit and never realized their annual wellness visit through Medicare was completely free. If you haven’t used your Welcome to Medicare visit or your annual wellness visit, that’s real value sitting on the table.

What’s NOT covered

  • Routine dental care — cleanings, fillings, dentures, extractions
  • Routine vision exams and eyeglasses
  • Hearing aids (though diagnostic hearing tests ordered by a doctor may be covered)
  • Long-term custodial nursing home care — help with daily living activities, as opposed to short-term skilled or medical care
  • Routine prescription drugs you pick up at a retail pharmacy — that’s Part D’s job, not Part B’s
  • Cosmetic surgery, unless medically necessary (such as reconstruction after an accident or mastectomy)
  • Most care received outside the United States, with very limited exceptions
  • Routine foot care, such as nail trimming, in the absence of a qualifying medical condition
  • Acupuncture, except for a narrow, specific chronic low back pain benefit
  • Concierge medicine fees and membership-style charges some practices add on top of standard care
  • Long-term care insurance-style services, including most home-based personal care that isn’t tied to a skilled medical need

Paul’s Honest Take: The dental and vision exclusions are the ones that surprise people most, especially since they’re such routine parts of healthcare for most adults. This is exactly why so many Medicare Advantage plans build dental, vision, and hearing benefits into their coverage — Original Medicare was simply never designed to include them, and that gap doesn’t go away on its own.

What Part B Costs in 2026

Part B has three separate cost components, and understanding all three matters:

Cost Component

2026 Amount

Standard monthly premium

$202.90

Annual deductible

$283

Coinsurance on most covered services

20%

The premium is deducted automatically from your Social Security check if you’re already collecting benefits. If you’re not yet collecting Social Security, you’ll receive a bill, typically every three months.

The deductible works differently than Part A’s — it’s a straightforward annual figure. You pay the first $283 of Medicare-approved outpatient costs each calendar year, and then Medicare’s cost-sharing kicks in.

The coinsurance is where the real risk lives. After your deductible is met, Medicare pays 80% of the Medicare-approved amount for most covered services, and you’re responsible for the remaining 20%. There is no yearly cap on this 20% under Original Medicare alone. If you have a $100,000 course of cancer treatment, your 20% share is $20,000 — unless you have a Medigap policy or Medicare Advantage plan absorbing that cost.

Paul’s Honest Take: I put this in bold because it’s genuinely the single most important number in this entire guide. That uncapped 20% is the whole reason Medigap and Medicare Advantage exist as products in the first place. Original Medicare by itself was never designed to protect you from a truly expensive year — it was designed to cover 80% of it and leave the rest to you.

IRMAA: What Higher Earners Actually Pay

If your income is above certain thresholds, you’ll pay more for Part B through the Income-Related Monthly Adjustment Amount (IRMAA) — based on your tax return from two years prior. For 2026, that means your 2024 income determines your premium tier.

2024 Income (Individual)

2024 Income (Married, Joint)

Total Part B / Month

$109,000 or less

$218,000 or less

$202.90

$109,001 – $137,000

$218,001 – $274,000

$284.10

$137,001 – $171,000

$274,001 – $342,000

$405.80

$171,001 – $205,000

$342,001 – $410,000

$527.50

$205,001 – $499,999

$410,001 – $749,999

$649.20

$500,000 and above

$750,000 and above

$689.90

At the top tier, you’re paying more than three times the standard premium. If your income has recently dropped — retirement, the loss of a spouse, or certain other life-changing events — you can appeal your IRMAA determination using Form SSA-44.

Do You Have to Enroll? And What Happens If You Don’t?

Technically, Part B is optional — Medicare won’t force you into it. But opting out without a valid alternative is genuinely risky, because of how the penalty structure works.

If you don’t sign up during your Initial Enrollment Period (the 7-month window around your 65th birthday) and you don’t have qualifying employer coverage, you’ll face a permanent 10% penalty added to your premium for every full 12-month period you went without Part B. That penalty doesn’t expire — you pay it for as long as you have Part B, which for most people means for the rest of your life.

Example: If you delayed enrollment by 24 full months without a valid exception, you’d pay an extra 20% on top of the standard $202.90 premium in 2026 — roughly $40.58 more, every month, permanently.

How Part B Works with Group Insurance

Just like Part A, whether you can safely delay Part B without penalty comes down to one specific number: how many employees your company has.

Companies with 20 or more employees: If you or your spouse are actively working and covered by a genuine group health plan, your workplace insurance is primary, and you can legally delay Part B without any penalty. When that employment or coverage eventually ends, you get an 8-month Special Enrollment Period to enroll in Part B penalty-free.

Companies with fewer than 20 employees: Medicare automatically becomes your primary insurer at 65, regardless of your employment status. You need to enroll in Part B right on schedule. If you don’t, your small employer’s plan can legally refuse to pay claims that Medicare should have covered first — potentially leaving you responsible for the full cost.

Paul’s Honest Take: I say this in nearly every guide I write, because it’s genuinely one of the costliest misunderstandings I encounter: “I have good coverage at work” and “I’m protected from Medicare’s enrollment deadlines” are two completely different statements, and whether the second one is true depends entirely on your employer’s size — not how generous the coverage feels. Confirm the actual employee count before you decide to delay anything.

Retiree Coverage Is Not the Same as Active Employer Coverage

This is a distinction that catches a genuinely large number of people off guard: the “20 or more employees” exception only applies to active employment. If you retire and your former employer offers you retiree health benefits — sometimes a genuinely good, comprehensive plan — that coverage does not create a Special Enrollment Period the way active group coverage does, and it does not exempt you from enrolling in Part B on time.

Paul’s Honest Take: I’ve seen this mistake more than once, and it’s an especially painful one because it happens to people who did everything right during their working years. Someone retires with a strong retiree health plan from a large employer, assumes it works the same way their active coverage did, and delays Part B — only to find out later that retiree coverage was never a valid reason to delay in the first place. The moment you stop actively working, that clock starts, regardless of how good your retiree plan looks on paper. If you’re retiring and keeping employer retiree benefits, treat enrolling in Part B as something to handle right on schedule, not something retiree coverage lets you postpone.

Why You Need Both Part A and Part B for Medigap or Medicare Advantage

Here’s a foundational requirement worth understanding clearly, since it shapes every other coverage decision in Medicare: you must be enrolled in both Part A and Part B before you can buy a Medigap policy or enroll in a Medicare Advantage plan. Neither product exists as a standalone substitute for Original Medicare — both are built specifically to work alongside it.

  • Medigap fills the cost-sharing gaps left by Original Medicare (Parts A and B) — it has nothing to fill in if you’re not enrolled in both parts to begin with.
  • Medicare Advantage legally must provide at least the same coverage as Parts A and B combined, which is only possible because you’re required to be enrolled in both before a Medicare Advantage carrier can enroll you.

Paul’s Honest Take: This surprises people who assume they can somehow “skip” Part B and go straight into a Medicare Advantage plan to avoid the extra premium. It doesn’t work that way — Part B enrollment, and its premium, is a prerequisite either way, whether you end up on Original Medicare with Medigap or on a Medicare Advantage plan. There’s no path through Medicare that avoids the Part B premium once you’re actually using the system.

Does Medicare Work If You’re a Veteran?

Yes — and if you have VA health benefits, understanding how the two systems relate is genuinely important, because they work differently than most people assume.

Medicare and VA benefits do not coordinate. These are two entirely separate systems that each pay only for care received within their own network. Medicare doesn’t pay for care you receive at a VA facility, and VA benefits don’t pay for care you receive from a non-VA doctor or hospital. You, the veteran, choose which system to use each time you seek care.

Here’s the critical point: having VA benefits does not exempt you from Medicare’s enrollment deadlines. VA coverage is not considered a qualifying reason to delay Part B without penalty. If you don’t enroll in Part B during your Initial Enrollment Period and you’re relying solely on VA benefits, you can still trigger the permanent late enrollment penalty.

Why the VA itself recommends enrolling in Medicare anyway:

  • It gives you access to civilian doctors and hospitals outside the VA system
  • VA healthcare funding depends on annual Congressional appropriations, which isn’t guaranteed to remain stable
  • If VA authorizes only part of your needed care at a non-VA facility, Medicare can help cover the rest
  • Having both gives you meaningfully more flexibility and security than relying on either system alone

Paul’s Honest Take: This is one of the most common misconceptions I run into with veterans specifically, and it’s an expensive one to get wrong. Good VA coverage feels like it should be enough, and it might genuinely handle most of your care — but it doesn’t protect you from the Part B enrollment clock the way employer coverage from a large company can. The VA itself actively encourages enrolling in Medicare Parts A and B for exactly this reason. If you have VA benefits and are approaching 65, this is worth a direct conversation before you assume you’re covered.

Veterans who enroll in Part B can also purchase a Medigap policy, which can be particularly valuable if you use non-VA providers regularly — though if you primarily rely on VA facilities for most of your care, the value of an added Medigap policy may be more limited, and worth weighing carefully.

How Long Does It Actually Take to Get Part B Approved?

This is one of the most practical, and most overlooked, pieces of planning — especially if you’re leaving a job after 65 and coordinating your Part B start date around the end of your employer coverage. Applying isn’t instant, and the timeline depends heavily on which enrollment window you’re using.

Enrollment Situation

Typical Processing Time

When Coverage Actually Starts

Initial Enrollment Period (around 65)

2–4 weeks, sometimes up to 6

1st of your birthday month (if applied in the 3 months before) or 1st of the month after you apply (if applied during or after your birthday month)

Special Enrollment Period (leaving employer coverage)

4–8 weeks, sometimes longer

1st of the month after your application is submitted

General Enrollment Period (Jan 1–Mar 31, missed window)

4–6 weeks

1st of the month after you apply

Why the Special Enrollment Period takes longer: applying after leaving employer coverage requires two forms, not one — Form CMS-40B (the actual Part B application) and Form CMS-L564 (Request for Employment Information), which your employer needs to complete to verify you had qualifying coverage. Social Security has to manually review both, which is exactly why this route consistently takes longer than a standard Initial Enrollment Period application.

Paul’s Honest Take: This timeline question comes up constantly with clients who are retiring or leaving a job after 65, and it deserves real attention — not just because of the penalty risk we’ve already covered, but because a slow approval can leave you with an actual gap in coverage if you time it too tightly. My standard advice: start this process at least 2 to 3 months before you need Part B to actually begin, not the week your employer coverage ends. If your former employer is slow to complete their portion of Form CMS-L564, that alone can hold up the entire application — so it’s worth following up with your HR or benefits department directly rather than assuming it’s been submitted.

Practical tips to avoid delays

  • Apply online through SSA.gov whenever possible. It’s consistently the fastest method — mailed or faxed forms are more prone to getting lost or delayed.
  • If you’re on a Special Enrollment Period, submit Form CMS-L564 alongside Form CMS-40B, not separately. They need to arrive together, and one incomplete form can stall the whole application.
  • Expect a short intake lag even with online applications. It can take several business days for an online submission to actually appear on a local Social Security agent’s screen — don’t panic if you call shortly after applying and they say they don’t see it yet.
  • Once approved, you don’t have to wait for your physical card. Your Medicare Beneficiary Identifier typically appears in your online Social Security or Medicare.gov account within a day or two of approval, and you can print a temporary card from there — the physical card generally arrives by mail within about 30 days.

Excess Charges: The Cost Almost Nobody Knows to Ask About

Here’s a detail that surprises even people who’ve been on Medicare for years: not every doctor who accepts Medicare agrees to accept Medicare’s approved amount as full payment.

Providers fall into three categories:

  • Participating providers accept Medicare assignment, meaning they agree to accept the Medicare-approved amount as payment in full. This covers the vast majority of providers — roughly 98% of doctors nationally.
  • Non-participating providers still accept Medicare patients but haven’t agreed to accept the standard rate. They can charge an excess charge of up to 15% above the Medicare-approved amount.
  • Opted-out providers have left the Medicare system entirely and can charge whatever they want under a private contract — Medicare pays nothing at all for care from these providers, except in emergencies.

How excess charges actually work: if the Medicare-approved amount for a service is $300 and you see a non-participating provider, they can legally charge up to an additional $45 (15%) on top, for a total bill of $345 — and that excess amount doesn’t count toward your Part B deductible.

Eight states currently prohibit or limit excess charges entirely: Connecticut, Massachusetts, Minnesota, New York, Ohio, Pennsylvania, Rhode Island, and Vermont. If you live in one of these states, you’re generally shielded from excess charges from providers within your state — though you could still face them if you receive care from a non-participating provider elsewhere.

Paul’s Honest Take: This is exactly why Medigap Plan G matters so much for people who want maximum flexibility. Plan G covers excess charges in full — Plan N does not. If you’re the kind of person who wants the freedom to see any doctor without worrying about billing surprises, that distinction is worth understanding clearly before you pick between the two. And regardless of which plan you choose, it’s always worth asking a new provider directly whether they accept Medicare assignment before your first appointment.

The HSA Rule: Part B Closes the Door Too

If you’re hoping to keep contributing to a Health Savings Account, know this clearly: enrolling in Part B — or any part of Medicare — ends your ability to make new HSA contributions. This isn’t unique to Part B; it applies the moment you enroll in Medicare in any form, including premium-free Part A.

If keeping your HSA active matters to you, the only way to legally delay both Part A and Part B is through qualifying employer coverage — which, as covered above, generally requires an employer with 20 or more employees. And because Part A enrollment can be backdated up to 6 months once you do enroll, it’s smart to stop HSA contributions 6 months before you plan to sign up for Medicare or file for Social Security, whichever comes first.

Frequently Asked Questions

Is there a cap on what I’ll pay for Part B services in a year? Not under Original Medicare alone — the 20% coinsurance has no yearly limit. A Medigap policy or Medicare Advantage plan is what actually caps your exposure.

What happens if I don’t sign up for Part B on time? You’ll generally face a permanent 10% penalty on your premium for every 12-month period you went without coverage, unless you qualify for a Special Enrollment Period through active employer coverage.

Do I need Part B if I have good coverage through a small employer? Almost certainly yes. If your employer has fewer than 20 employees, Medicare becomes your primary insurer at 65 regardless of your job coverage, and not enrolling can leave you exposed to unpaid claims and a lifelong penalty.

Do veterans need Medicare Part B if they have VA benefits? Generally, yes. Medicare and VA benefits don’t coordinate — each only pays for care within its own system — and VA coverage doesn’t exempt you from Medicare’s enrollment deadlines or penalties.

What is a Part B excess charge? An additional charge, up to 15% above the Medicare-approved amount, that a non-participating provider can legally bill you. It doesn’t count toward your deductible, and only Medigap Plan G (among current plans) covers it in full.

Can I keep contributing to my HSA if I enroll in Part B? No. Enrolling in any part of Medicare, including Part B, ends your HSA contribution eligibility going forward.

How long does it take to get approved for Part B? It depends on the enrollment window. Initial Enrollment Period applications typically process in 2–4 weeks. Special Enrollment Period applications, used when leaving employer coverage, generally take 4–8 weeks since Social Security must manually verify your prior coverage using Form CMS-L564. Start the process at least 2–3 months before you need coverage to begin, especially when coordinating around a job ending.

The Bottom Line

Part B is the half of Medicare that covers your everyday medical care — and it’s also where the real financial exposure of Original Medicare lives, thanks to that uncapped 20% coinsurance. Whether you should enroll at 65, whether you can safely delay, and how much of that exposure you’re carrying all depend on details specific to your situation: your employer’s size, your income, your VA status, and which doctors you actually see.

If you want help sorting out exactly how Part B applies to your specific circumstances — or want to understand how Medigap or Medicare Advantage could close that uncapped coinsurance gap — that’s exactly the conversation I have with clients every day, at no cost to you.

Call 631-358-5793 or visit paulbinsurance.com to set up a time to talk it through.

Paul Barrett, CMIP, is the founder of The Modern Medicare Agency, based in Melville, NY, and has spent 18+ years exclusively helping people navigate Medicare — never life insurance, never annuities, just Medicare. He’s licensed in 37 states, represents more than 40 carriers, and has personally helped over 5,000 clients choose coverage that actually fits their lives.

Figures current as of 2026 and sourced from CMS, Medicare.gov, and the Social Security Administration. Individual circumstances vary, especially around employer coverage, VA benefits, and income-based premiums — always verify your specific situation before making enrollment decisions.

Sources

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