How does a windfall change your retirement date?
Age
48
Location
Boston, MA
Income
$145k/yr
Saved
$340k (+ windfall)
A 48-year-old Boston professional earns $145k and has $340k saved — a solid but unremarkable position. Then a parent's estate delivers a $450k inheritance in 12 months. Does this windfall let them retire in their late 50s instead of mid-60s? And how should the lump sum be invested?
The earliest retirement age at which this plan does not run out of money is 51, after 3 more years of full-time work. Market risk matters more than that headline: the earliest age that succeeds in at least 80% of 500 Monte Carlo simulations is 54.
| Retire at | Full-time years left | Semi-retired years | Best Monte Carlo success |
|---|---|---|---|
| 51 | 3 | 0 | 38% |
| 52 | 4 | 0 | 63% |
| 53 | 5 | 0 | 77% |
| 54 | 6 | 0 | 88% |
| 55 | 7 | 0 | 92% |
EARLIEST 80%+ PLAN: Retire at Age 54 Switch to semi-retirement at age 54 (after 6 high-salary years). Portfolio bridges to full retirement at 54.
Growth rate (4.0%) keeps compounding during spending — the extra buffer matters most against bad early-retirement market sequences.
Social Security: $38k/yr starting at age 67 is included. Healthcare: $15k/yr before Medicare at 65.
Across the simulated market histories (in future dollars, not adjusted for inflation), the median portfolio is $528k at 70, $473k at 80, $297k at 90. In a poor sequence of returns (10th percentile) it is $35k at 70, $76k at 80, $0k at 90.
This example uses illustrative figures and should not be treated as financial advice.