Series 3 – Parts
Getting Roth Conversions Right
Most Roth conversion calculators skip two costs that decide the whole answer: what you lose in ACA subsidies during your conversion years, and what a dollar today is actually worth against a dollar saved decades from now.
This series builds the framework properly and ends with a calculator you can run your own numbers through
The Scenario
NPV: Conversion vs. Do Nothing
| STATEGY | APPRAOCH | NPV |
| DO NOTHING | Baseline: collect ACA subsidies, let balance grow, take RMDs | $0 |
| CONVERT AT 55-59 | $100,000/yr during ACA years | -$27,652 |
| CONVERT AT 65-69 | $100,000/yr after Medicare starts | $23,034 |
5%
Discount Rate
$20,000
Annual ACA Subsidy Risk
5 years
Conversion Window Modeled
Parts in This Series
Each part builds on the last. Start at Part 1.
1
Why Most Roth Conversion Calculators Get It Wrong
Sarah and Tom run the same $100,000/year conversion at two different ages and land on opposite sides of zero. The gap comes down to three things most calculators skip entirely.
2
When Roth Conversions Win Big
At equal tax rates, neither converting early nor waiting is a clear win. Change the rate on either side of the equation and the math stops being close.
3
The Spreadsheet, the Methodology, and Why I Built It
A tab-by-tab walkthrough of the model behind Parts 1 and 2, including the IRS Uniform Lifetime Table, the do-nothing baseline, and what the tool deliberately leaves out.