Retiring Soon? What to Know About Form SSA-44 and Leaving Employer Coverage for Medicare

By Marc Gilman

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Key Takeaways:

Form SSA-44 lets you ask Social Security to base your Medicare IRMAA surcharge on your current income instead of the tax return from two years ago — but only if a qualifying life event caused the drop.
Retirement (work stoppage) is one of eight qualifying events, and it’s the most straightforward one to document.
COBRA does not extend your Medicare enrollment window. This is the single most expensive, most common mistake people make when leaving a job at 65 or older — and the penalty is often permanent.
You generally have 8 months to enroll in Part B penalty-free after employer coverage ends — but only 2 months for Part D or a Medicare Advantage plan. Different clocks, different deadlines.
If you have an HSA, Medicare Part A can be retroactive up to 6 months, which can accidentally turn HSA contributions into IRS penalties if you don’t stop contributing in time.

Retiring brings two separate but related Medicare tasks: actually enrolling in Medicare correctly, and making sure you’re not overpaying once you’re on it. Getting either one wrong can be expensive — and in some cases, permanently so. Here’s what to know about both.

Part One: Lowering Your IRMAA Surcharge With Form SSA-44

What Is IRMAA, and Why Does Retirement Matter to It?

IRMAA (Income-Related Monthly Adjustment Amount) is a surcharge added to your Medicare Part B and Part D premiums if your income is above a certain threshold. For 2026, that threshold is $109,000 for individuals and $218,000 for married couples filing jointly — and it’s charged per person, not per household.

Here’s the catch: Medicare doesn’t look at your income this year. It looks at your tax return from two years ago. So if you were still working and earning a full salary two years before you retire, Medicare may charge you IRMAA based on that higher income — even in your first year of actually being retired, when your real income has already dropped.

What Form SSA-44 Does

Form SSA-44 lets you ask Social Security to recalculate your IRMAA using a more current income estimate instead of the two-year-old tax return, but only if you’ve had one of eight specific qualifying life events:

Marriage
Divorce or annulment
Death of a spouse
Work stoppage (retirement, layoff, or selling a business)
Work reduction
Loss of income-producing property (disaster, fraud, theft)
Loss of pension income
An employer settlement payment related to bankruptcy or reorganization

Retirement falls under work stoppage — the most common reason people file, and generally the easiest to document.

How to File It

Wait until you actually receive an IRMAA determination letter from Social Security stating you owe the surcharge. Don’t file preemptively.
Identify your qualifying event and the date it occurred.
Provide your estimated income for the current year, along with documentation — for retirement, that’s typically a letter from your former employer confirming your retirement date, or a final pay stub.
Submit the form to your local Social Security office.

If your appeal is approved, Social Security recalculates your premium going forward, and reimburses any excess you already paid — typically by direct deposit or a mailed check.

One detail worth knowing: each spouse needs to file their own Form SSA-44. IRMAA is assessed per person, so one spouse’s approved appeal doesn’t automatically apply to the other.

Part Two: What to Watch For When You Leave Employer Coverage

Separately from IRMAA, actually enrolling in Medicare correctly when you leave employer coverage has its own set of traps — and unlike an IRMAA overpayment, some of these mistakes can’t be undone.

The 8-Month Window — And the COBRA Trap

If you’re 65 or older and covered by an employer group health plan when you stop working, you get a Special Enrollment Period (SEP): 8 months to enroll in Part B without penalty, starting the month after your employment ends or your group coverage ends — whichever happens first.

Here’s where people get into serious trouble: COBRA does not extend this window. If you leave your job and elect COBRA, your 8-month SEP clock is already running from the day your active employment coverage ended — not from whenever COBRA eventually runs out. Someone who takes 18 months of COBRA and waits for it to expire before applying for Medicare will have missed their SEP by about 10 months.

Missing the window means waiting for the General Enrollment Period (January 1 – March 31), with coverage not starting until later, and a Part B late enrollment penalty: 10% of the standard premium for every full 12-month period you were eligible but didn’t enroll — added to your premium permanently, for life.

The 20-Employee Rule

This SEP only applies if your employer coverage came from an employer with 20 or more employees. If you worked past 65 for a smaller employer, Medicare considers itself your primary payer starting at 65 regardless of your group coverage — meaning your Part B penalty clock may have already been running since your 65th birthday, not your retirement date. If you’re not sure your employer meets this threshold, it’s worth confirming directly rather than assuming your group coverage protected you.

Part D Has a Shorter Clock

The 8-month window applies to Part B. For Part D or a Medicare Advantage plan, you only get 2 months after employer coverage ends. It’s easy to assume both run on the same timeline — they don’t, and missing the shorter Part D window can mean a gap in drug coverage and its own separate late enrollment penalty.

The Forms You’ll Actually Need

To enroll using this SEP, you’ll submit two forms together:

CMS-40B — the actual Application for Enrollment in Medicare Part B. This is where you request enrollment and, if applying during an SEP, request your effective date.
CMS-L564 — Request for Employment Information, which proves you had qualifying group coverage through current employment. You complete Section A yourself; your employer completes Section B (employment and coverage dates) and signs it.

Once your employer returns the completed form, mail or fax both forms together to your local Social Security office — not separately. Submitting them as a pair is what documents that you’re using the SEP correctly, rather than risking Social Security defaulting your application into the General Enrollment Period.

If your employer won’t complete Section B, alternative proof — W-2 forms, pay stubs, or health insurance cards showing coverage dates — can sometimes work instead, though it’s better to get the employer’s signature if at all possible.

One more thing worth knowing: CMS-40B assumes you already have Part A. Per CMS’s own instructions on the form, it’s only for people who already have Part A and are enrolling in Part B — if you don’t have Part A yet, don’t fill out CMS-40B at all. You’d need to contact Social Security directly to apply for Medicare for the first time instead.

(Source: Form CMS-L564, Centers for Medicare & Medicaid Services; Form CMS-40B, Centers for Medicare & Medicaid Services)

The HSA Trap Most People Never See Coming

If you have a Health Savings Account, there’s a rule that catches even financially sophisticated people off guard: Medicare Part A can be retroactive up to 6 months once you enroll (though never earlier than your 65th birthday). The moment any part of Medicare becomes effective — including premium-free Part A — you’re no longer eligible to contribute to an HSA.

If you keep contributing during that retroactive window without realizing it, those contributions become excess contributions under IRS rules, triggering a 6% excise tax for every year they remain uncorrected. The commonly recommended fix: stop HSA contributions at least six months before you plan to apply for Medicare or Social Security — since applying for Social Security benefits can trigger automatic Part A enrollment on its own.

Putting It Together

Retirement often means dealing with all of this at once: enrolling correctly on the right timeline, watching out for the COBRA and HSA traps, and — separately — making sure your IRMAA reflects your actual new income rather than your final working year. None of these are related enough to fix with the same phone call, which is exactly why they’re easy to miss.

What To Do Next

If retirement is on the calendar, the safest approach is to map out your enrollment deadlines and your SSA-44 opportunity at the same time, before your employer coverage actually ends.

If you need further information about how your own transition off employer coverage should be timed, we’re here to help — no cost, no obligation.