The calculators use 8 data files. Each is parsed by a script straight from the publisher’s own page or document, never typed in by hand, and stored with the address it came from, the edition the publisher printed and the date we retrieved it. A copy of the original download is kept beside it with a checksum, so anyone can confirm the file still matches its source.
Every file is also tested against figures the publisher prints. The SSA table, for example, has to reproduce the SSA’s published life expectancy at every age from 40 up, and the IRS limits file is checked against the sentences in the IRS notice. When a new edition comes out, it gets a new file and its own tests; an old file is never edited. The methodology explains how the calculators use them.
Data files, by topic
The list below is generated from the files themselves when the site is built, so the editions and dates are always the ones the calculators are using.
Life tables and life expectancy
- IRS Publication 590-B (2025) life expectancy tables
Internal Revenue Service, US Department of the Treasury. Edition: Publication 590-B (2025), Distributions from Individual Retirement Arrangements (IRAs). For use in preparing 2025 Returns. Retrieved October 22, 2026.
Used by IRS life expectancy tables and RMD. - SSA period life table (2023)
Social Security Administration, Office of the Chief Actuary. Edition: Period Life Table, 2023, as used in the 2026 Trustees Report. Retrieved October 22, 2026.
Used by Annuity calculator, How long will my money last?, Life expectancy calculator.
Federal tax and retirement plan rules
- IRS 2026 federal income tax brackets and standard deduction
Internal Revenue Service. Edition: Rev. Proc. 2025-32. Retrieved October 22, 2026. - IRS early distribution, withholding, SEPP and plan loan rules
Internal Revenue Service. Edition: Page last reviewed or updated 11-Dec-2025. Retrieved October 22, 2026.- irs.gov/retirement-plans/plan-participant-employee/retirement-topics-exceptions-to-tax-on-early-distributions: Page last reviewed or updated 11-Dec-2025
- irs.gov/retirement-plans/retirement-plans-faqs-regarding-loans: Page last reviewed or updated 26-Feb-2026
- irs.gov/retirement-plans/substantially-equal-periodic-payments: Page last reviewed or updated 23-Jul-2026
- irs.gov/retirement-plans/plan-participant-employee/rollovers-of-retirement-plan-and-ira-distributions: Page last reviewed or updated 31-May-2026
- IRS 2026 retirement plan, IRA and HSA limits
Internal Revenue Service. Edition: Notice 2025-67. Retrieved October 22, 2026.- irs.gov/pub/irs-drop/n-25-67.pdf: Notice 2025-67
- irs.gov/newsroom/401k-limit-increases-to-24500-for-2026-ira-limit-increases-to-7500: IR-2025-111, Nov. 13, 2025
- irs.gov/retirement-plans/cola-increases-for-dollar-limitations-on-benefits-and-contributions: Page last reviewed or updated 24-Aug-2026
- irs.gov/pub/irs-drop/rp-25-19.pdf: Rev. Proc. 2025-19
- irs.gov/publications/p969: Publication 969 (2025)
- irs.gov/retirement-plans/plan-participant-employee/retirement-topics-403b-contribution-limits: Page last reviewed or updated 16-Mar-2026
- irs.gov/pub/irs-pdf/p4484.pdf: Publication 4484 (Rev. 4-2021)
- irs.gov/retirement-plans/how-much-salary-can-you-defer-if-youre-eligible-for-more-than-one-retirement-plan: Page last reviewed or updated 26-Feb-2026
- irs.gov/retirement-plans/plan-participant-employee/retirement-topics-catch-up-contributions: Page last reviewed or updated 07-May-2026
- irs.gov/pub/irs-drop/n-23-62.pdf: Notice 2023-62
- irs.gov/publications/p590a: Publication 590-A (2025)
Federal employee benefits
- OPM FERS basic annuity rules (with SSA earnings test amounts)
U.S. Office of Personnel Management. Edition: Eligibility (no date printed on the page). Retrieved October 22, 2026.- opm.gov/retirement-center/fers-information/eligibility: Eligibility (no date printed on the page)
- opm.gov/retirement-center/fers-information/computation: Computation (no date printed on the page)
- opm.gov/retirement-center/fers-information/types-of-retirement: Types of Retirement (no date printed on the page)
- opm.gov/retirement-center/my-annuity-and-benefits/annuity-payments: Annuity Payments (no date printed on the page)
- opm.gov/retirement-center/publications-forms/pamphlets/ri90-1.pdf: RI 90-1, Revised April 1998 (still listed on OPM's pamphlets page)
- ssa.gov/oact/cola/rtea.html: Exempt Amounts Under the Earnings Test; table runs to 2027
- TSP rules 2026: agency contributions, vesting, catch-ups and funds
Federal Retirement Thrift Investment Board (tsp.gov). Edition: Summary of the Thrift Savings Plan, TSPBK08 (1/2026). Retrieved October 22, 2026.- tsp.gov/publications/tspbk08.pdf: Summary of the Thrift Savings Plan, TSPBK08 (1/2026)
- tsp.gov/what-is-contribution: Last updated September 10, 2026
- tsp.gov/contribution-limits: Last updated September 24, 2026
- tsp.gov/what-is-individual-fund: Last updated September 14, 2026
- tsp.gov/what-is-lifecycle-fund: Last updated September 28, 2026
Market returns and inflation
- US historical returns: S&P 500, 10-year Treasury bond and CPI inflation, 1928–2025
Aswath Damodaran, NYU Stern School of Business ("Historical Returns on Stocks, Bonds and Bills"). Edition: Annual returns 1928–2025; data page says the most recent update was on January 9, 2026. Retrieved October 22, 2026.
Used by How long will my money last?.
Other publications the pages cite
Some rules are stated in words on a page, with the source linked where it is used, rather than read from a data file. These, and the background references the Learn pages cite, are listed here.
The corrections policy says how we check and fix a figure that doesn’t match its source.