IRS Publication 590-B, Appendix B, Table III
Uses the Uniform Lifetime Table and the applicable modeled starting age. Account ownership and individual circumstances can change actual requirements.
View the IRS source
Transparent by design
Know what the illustration assumes—and which version produced it.
Retirement Tax Studio separates the calculation code, source rules, and disclosures so each can be reviewed and released without quietly changing past work.
Active rulesirs-p590b-2025-reviewed-2026-08-21Reviewed 2026-08-21
Current model
What the calculator does
This is a focused educational comparison, not personal tax software.
User-selected assumed effective tax rate
The selected 15%–40% rate is applied consistently when the bracket-aware check is off. It is an effective-rate assumption, not a tax-return calculation.
Current conversion tax estimate
The optional planning check stacks a full, taxable conversion on top of taxable ordinary income before conversion using the published 2026 federal brackets, then adds an optional state-rate estimate. The future stay-qualified path still uses the selected effective tax rate.
View the IRS sourceIRMAA timing warning
The optional check compares MAGI before and after the conversion using the published 2026 Part B and Part D surcharge schedule. A 2026 conversion generally affects the 2028 premium determination; 2028 thresholds and premiums are not yet published, so this current-dollar warning is shown separately and is not included in ending balances.
View the CMS sourceConstant annual illustration
The public starting assumption is 7% and can be adjusted from 0% to 12%. Returns, fees, and product charges are not predicted.
Modeled after-tax dollars
The stay-qualified path combines the IRA after estimated ending tax with after-tax RMD money. The pay-tax-today path assumes tax is paid from the account and the remainder grows tax-free.
Controlled updates
How rule changes become a release
Law and guidance can change. The calculator is organized so an RMD table, tax-model assumption, or disclosure can be updated deliberately instead of being buried in the page.
- MonitorReview authoritative sources quarterly and complete a required January review.
- DocumentOpen a change record with the source, effective date, affected users, and proposed rule.
- TestAdd fixed examples and regression tests before changing the active version.
- ReviewObtain appropriate tax, legal, and compliance review before production use.
- ReleasePublish new version identifiers and retain the prior release for audit and rollback.
Calculationreference-compatibility-plus-net-2026.6
Rulesirs-p590b-2025-reviewed-2026-08-21
Disclosureeducational-after-tax-comparison-2026.3