Field note 04
Retirement income planning · 5 min read
What 1,000 simulated retirements taught us about Long Island public-sector households.
A few patterns show up almost every time when the analysis runs against a real LI public-sector or hospital-system household. The bracket-fill window, the IRMAA cliff at 63, and the eight-to-ten-year bridge between retirement and Social Security claim age.
By Dan Zimon · May 27, 2026
The analyzer at /retirement-analysis runs the household's actual numbers through 1,000 simulated paths. After running it against a wide sample of Long Island public-sector and hospital-system shapes, NYSTRS retirees, PFRS pensioners, Northwell and Stony Brook 403(b) holders, families with a wife on TIAA and a husband on a 401(k), three patterns show up almost every time. None of them is novel. All of them are easy to underweight if a household never looks at the year-by-year detail.
1. The bracket-fill window between retirement and RMDs
For households retiring in their early sixties, there is usually a window of seven to twelve years where ordinary income drops sharply but required minimum distributions have not yet started. RMDs begin at age 73 today, moving to 75 from 2033 (SECURE 2.0). That gap is the natural home for filling unused 12% or 22% bracket space with Roth conversions, but only if it gets done before RMDs arrive and start filling the brackets on their own.
A household that ignores the window forfeits the chance and then watches RMDs at age 73 (or 75) push them into a higher marginal rate than they were paying during working years. The arithmetic is unforgiving. Once RMDs start, the bracket is filled whether the household wanted that or not. The window closes on its own.
2. The IRMAA cliff at age 63
Medicare premiums for Parts B and D are means-tested via IRMAA tiers. The tiers are calculated on a two-year lookback. What the household earned at age 63 determines the premium at age 65. So the income decisions in the years leading up to Medicare have a real, ongoing cost. Crossing a tier line by even one dollar steps the household up to the next surcharge bracket for the entire year.
The Roth conversion ladder analysis in the tool caps each year's recommended conversion at the IRMAA Tier 1 line once the household is Medicare-relevant. The point is not to avoid Medicare costs entirely. It is to avoid the inadvertent cliff that turns a $500 over-conversion into a $1,500 increase in annual surcharges.
3. The eight-to-ten-year bridge to Social Security
Most public-sector retirees can claim Social Security as early as age 62, but the SSA's benefit formula penalizes early claiming sharply. Full Retirement Age is 67 for everyone born 1960 or later. Delaying past FRA earns delayed retirement credits at 8% per year up to age 70. Roughly a 24-32% lift on the lifetime benefit if claimed at 70 instead of 67, and a 76% lift over claiming at 62.
For households retiring at 60 or 62, the gap between retirement and the optimal SSA claim is the most exposed period in the entire plan. The portfolio carries the full spending load. The wife's TIAA or the husband's NYSTRS pension may cover part of it; the rest comes from withdrawals during a window where sequence-of-returns risk hits the hardest because the household has no Social Security floor to fall back on.
The pattern that emerges
When the same Monte Carlo runs across many LI households, the bad-sequence tail (the 10th percentile) is almost always driven by one of these three: a Roth conversion window missed, an IRMAA tier crossed inadvertently, or a SSA claim taken too early under cash-flow pressure during the bridge. The headline plan-success rate gets all the attention. The cause of the worst outcomes is usually one of these three decisions, made in a single year, with effects that compound for the rest of the household's life.
What that means for how a household plans
None of this changes the principle that household-by-household, the right answer is specific to the household. But the patterns suggest where a conversation tends to be most useful: the conversion window between retirement and RMD start, the income posture in the two years before Medicare, and the bridge years between retirement and the SSA claim age. Those three places, more than the headline portfolio question, are where the analysis tends to point.