If you're moving back to the US from Switzerland after age 65, two clocks start ticking the moment your plane lands — and they're easy to miss because nothing about them feels urgent at the time. The first is a hard 60-day deadline to sign up for Medicare Part B, the part of Medicare that covers doctor visits and outpatient care. The second is quieter: a large Swiss Pillar 2 pension lump sum withdrawn in your move year can show up as a premium surcharge on your Medicare bill roughly two years later. Neither trap is disastrous once you see it coming. Both are very easy to walk into if nobody points them out.
The 60-Day Window Starts the Day You Land — Not the Day You Decide to Enroll
Medicare gives people who had qualifying health coverage abroad a Special Enrollment Period (SEP) — a limited window to sign up for Part B outside the usual annual periods, without being treated as late. For returning expats, that window is 60 days, and it starts counting from the month your foreign coverage ends, which for most people is the month they move back and their Swiss KVG or employer plan stops. It does not start when you get around to calling Social Security, and it does not pause because you're jet-lagged, moving apartments, or waiting for a Social Security number update.
60 days
Special Enrollment Period to sign up for Medicare Part B after your foreign health coverage ends
If you enroll within that window, coverage typically begins the first of the month after you sign up. You can apply online through the Social Security Administration, by phone, or in person at a local Social Security office — there's no need to wait until you're fully settled to start the process.
What Happens If You Miss It
Miss the 60-day window and you're pushed into the General Enrollment Period, which only runs January 1 through March 31 each year, with coverage not starting until July 1. That gap alone can leave you without outpatient coverage for months. Worse, a late-enrollment penalty attaches to your Part B premium permanently — an extra 10% for every full 12-month period you were eligible but not enrolled and without other qualifying coverage. Someone who spent five years abroad after their SEP lapsed unnoticed could be looking at a 50% surcharge on their Part B premium, for the rest of their life on Medicare.
This penalty doesn't expire
Unlike most tax or insurance penalties, the Medicare Part B late-enrollment surcharge isn't a one-time fee — it's recalculated as a percentage add-on to your premium every single month, for as long as you're enrolled in Part B. That's what makes the 60-day window worth marking on a calendar before you even book your flight.
The Second Trap: IRMAA and the Two-Year Lookback
Even if you nail the Part B deadline, a separate issue can quietly raise your premiums two years later: IRMAA, short for Income-Related Monthly Adjustment Amount. IRMAA is a surcharge added to your Part B and Part D (prescription drug) premiums when your income is above certain thresholds. What catches people off guard is the lookback — your premium in a given year is based on your tax return's Modified Adjusted Gross Income (MAGI) from two years earlier. Your 2026 Medicare premium, in other words, is set using your 2024 tax return.
For 2026, the IRMAA thresholds start at $109,000 in MAGI for single filers and $218,000 for those married filing jointly. There are five tiers above that, and they climb quickly: the first tier adds $81.20 a month to Part B and $14.50 to Part D, while the top tier — MAGI of $500,000 or more single, $750,000 joint — adds $487 a month to Part B and $91 to Part D.
$81.20–$487/month
Additional Part B premium across the five 2026 IRMAA tiers, depending on MAGI
The mechanism that trips up returning expats specifically is the lump sum. If you withdraw your Swiss Pillar 2 occupational pension as a lump sum when you leave Switzerland — a common and often sensible move — that withdrawal is generally taxable to the US as ordinary income in the year you receive it. Swiss withholding tax also applies at the cantonal rate, often in the 5–10% range, and part of that may be reclaimable under the tax treaty. But from the IRS's perspective, the full lump sum lands on your return for that year. A CHF 400,000 withdrawal (roughly $450,000) can push your MAGI into a higher IRMAA tier for that tax year — and two years later, your Medicare premiums jump accordingly, typically in the $200–$500 a month range, even though your actual ongoing income in retirement may be far lower.
Sequencing Matters: Withdrawal Timing vs. Enrollment Timing
Here's the part worth thinking through before you leave Switzerland, not after: the year you withdraw your Pillar 2 and the year you enroll in Medicare don't have to be the same tax year. If your situation allows some flexibility, delaying the lump-sum withdrawal until the calendar year after you've already returned and enrolled can push the IRMAA spike further out, or in some cases reduce its size if your income is otherwise lower in the following year. If the withdrawal genuinely has to happen in your move year — because of Swiss timing rules, employer requirements, or the pension fund's own process — the more useful move is simply to expect the spike and budget for it two years ahead, rather than be surprised by a Medicare premium notice that seems to have appeared out of nowhere.
- Confirm the exact date your Swiss health coverage and any employer coverage end — that date starts your 60-day Part B clock.
- Apply for Part B through the Social Security Administration well inside the 60-day window; don't wait until you're fully unpacked.
- Before finalizing the Pillar 2 lump-sum date, map out which US tax year the withdrawal will land in and what your MAGI looks like for that year.
- If a same-year withdrawal is unavoidable, estimate the IRMAA tier it will trigger two years later and set aside the difference so it doesn't feel like a surprise bill.
- Keep documentation of the withdrawal as a one-time event — you may need it later if you pursue relief.
If the Spike Already Happened: Form SSA-44
If your IRMAA surcharge was triggered by a genuinely one-time event — retirement, a pension lump sum, loss of income-producing property — the Social Security Administration has a mechanism to reconsider it: Form SSA-44, Medicare Income-Related Monthly Adjustment Amount – Life-Changing Event. Filing this form lets you ask Social Security to base your premium on a more recent, more representative year of income instead of the automatic two-year-old return. It's a real path, but it isn't automatic — you need to document that the event qualifies and that your current income doesn't reflect the lump sum, and approval is a judgment call by the SSA, not a guarantee.
Two decisions, one plan
The Part B enrollment deadline and the Pillar 2 withdrawal timing are two separate systems with two separate clocks, but they're best planned together, before you leave Switzerland rather than after you land. This is exactly the kind of cross-border sequencing question we work through with clients at US Expat Wealth — people moving between the Swiss and US systems who want a plan rather than a scramble.
None of this is a reason to panic about either deadline. The 60-day Part B window is generous if you know it's there, and the IRMAA lookback is entirely predictable once you understand how it works — it's not a penalty for doing anything wrong, just a mechanical result of when income lands on a tax return. The goal isn't to avoid Medicare or avoid your pension; it's to sequence the two so neither one ambushes you a year or two down the road. If your Pillar 2 withdrawal, your move date, and your Medicare enrollment all need to line up, this is exactly the kind of situation where getting a second set of eyes on the timeline before you finalize dates is worth far more than the time it takes.