The healthcare bridge fund: paying for coverage from early retirement to Medicare

Ask early retirees what nearly kept them working and the answer is rarely the portfolio — it's health insurance. Between your last employer plan and Medicare at 65 sits a gap of five, ten, sometimes fifteen years where you are the group plan, the HR department, and the subsidy engineer all at once. The good news: this is a solvable, sizable-in-advance problem. The key insight is that it's actually two problems — a cash-flow problem (paying the bills) and a MAGI problem (what your income looks like on paper) — and the accounts that solve one can wreck the other.

Sizing the bridge

Start with the unsubsidized worst case, because subsidies depend on income choices you haven't made yet. A 60-year-old couple buying unsubsidized silver coverage commonly faces $1,800–$2,500/month in premiums, plus a family out-of-pocket maximum around $18,000. Call it $30,000–$48,000 per year fully loaded in a bad year. Over a ten-year bridge from 55 to 65, the unsubsidized ceiling is $300,000–$450,000 — and the subsidized floor, for a couple keeping MAGI low, can be under $5,000 a year in premiums. That enormous spread is the whole game: your healthcare cost in early retirement is substantially a function of how you generate income, not just how much you spend.

Cash flow vs MAGI: the two-ledger mindset

Marketplace subsidies key off modified adjusted gross income — AGI plus tax-exempt interest, untaxed Social Security, and excluded foreign income. What matters is not how much you spend, but how much taxable income you create while funding that spending. Spending $80,000 a year while showing $45,000 of MAGI is routine for early retirees with the right account mix. Each dollar source hits the two ledgers differently:

The tension worth naming: the early-retirement years are also the classic low-bracket window for Roth conversions, and every dollar converted raises MAGI and shrinks subsidies. There's no universal answer — a household with $2 million in traditional accounts may rationally sacrifice subsidies for a few years of aggressive conversions before RMDs and IRMAA loom, while a household with mostly taxable and Roth assets should protect the subsidy and skip conversions. Model both; the crossover is real and household-specific. (For the mechanics of the subsidy cliff itself, see the ACA premium tax credit article — this piece is about funding the bridge.)

The drawdown order that funds the bridge

1. 1
   Years 1–2: spend the cash buffer

   Retire with 1–2 years of expenses in cash raised before your final paycheck stops (or from your last bonus/severance). This lets year-one MAGI be nearly zero — but not below the marketplace floor: fall under ~138% of the federal poverty level in expansion states and you're routed to Medicaid instead of subsidized marketplace coverage. Some retirees intentionally realize income to stay above the floor.

2. 2
   Core years: harvest high-basis taxable lots

   Sell the shares you bought most recently (highest basis) to generate spending cash with minimal realized gain. A $60,000 sale with $12,000 of gain adds only $12,000 to MAGI — and if you stay inside the 0% capital gains bracket, it may add nothing to your tax bill either.

3. 3
   Deploy banked HSA receipts as a pressure valve

   Years of unreimbursed medical receipts become an on-demand, MAGI-free ATM. Big irregular expense in October threatening to push you over a subsidy threshold? Reimburse $8,000 of old receipts instead of selling appreciated shares.

4. 4
   Use Roth contributions (not earnings) for fine-tuning

   Roth IRA contribution basis comes out tax- and penalty-free at any age. It's the perfect December top-up when you need cash but zero additional MAGI.

5. 5
   Age 59½+: blend in traditional dollars deliberately

   Once penalties disappear, fill low tax brackets with traditional withdrawals or conversions up to — never accidentally past — whichever MAGI target you're managing that year.

Bad-year planning: the out-of-pocket max is part of the fund

Premiums are the predictable half. The bridge fund also needs the out-of-pocket maximum — potentially $9,000+ per person — sittable in cash or near-cash every single year, because a cancer diagnosis at 58 shouldn't force appreciated-asset sales that torch next year's subsidy too. Under 250% of the poverty level, cost-sharing reductions shrink deductibles and OOP maxes dramatically on silver plans, which is one more reason low-MAGI years are worth engineering in heavy-treatment years if you can see them coming (a scheduled surgery, ongoing treatment).

The bottom line

The Medicare bridge is a known, fundable liability — plan for something near $30,000–$45,000 a year unsubsidized and let smart income engineering claw most of it back. Build the fund from cash, high-basis taxable lots, banked HSA receipts, and Roth basis; spend them in an order that keeps paper income where you want it; and decide deliberately each year whether subsidies or Roth conversions win the low-bracket window. Ten years of $20,000 annual subsidies is $200,000 — for many early retirees, the highest-paying part-time job they'll ever hold is managing their own MAGI.