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IRS Sources & Official References
Every number in every StackedTools calculator comes from an official IRS publication. Here are the exact sources — cited, linked, and organized by tool.
Not financial advice. StackedTools calculators are for informational purposes only and apply 2026 IRS limits. Tax law is complex — consult a CPA or enrolled agent for personalized advice.
Primary Citations
The IRS publications and notices that directly inform our 2026 calculator limits.
Retirement Plan Cost-of-Living Adjustments for 2026
Official source for 2026 401(k), 403(b), 457, Solo 401(k), SEP-IRA, SIMPLE IRA, and IRA contribution limits and phase-outs.
HSA and HDHP Inflation Adjustments for 2026
Defines 2026 Health Savings Account (HSA) contribution limits for self-only and family coverage, plus HDHP minimum deductibles and out-of-pocket maximums.
Tax Year 2026 Inflation Adjustments
Sets 2026 federal income tax brackets, standard deductions, and other inflation-adjusted tax parameters.
Retirement Plans for Small Business (SEP, SIMPLE, and Qualified Plans)
Comprehensive guide to retirement plans available to self-employed individuals and small business owners, including contribution rules, deduction limits, and plan comparisons.
Contributions to Individual Retirement Arrangements (IRAs)
Rules for contributing to traditional and Roth IRAs, including deductibility, income limits, and rollover rules.
Distributions from Individual Retirement Arrangements (IRAs)
Required Minimum Distribution rules, early withdrawal penalties, and Roth IRA distribution ordering rules.
Health Savings Accounts and Other Tax-Favored Health Plans
Complete HSA rules including eligibility, contribution limits, qualified medical expenses, and coordination with Medicare.
Employer's Tax Guide
Federal income tax withholding tables and payroll tax rules for employers.
Tax-Sheltered Annuity Plans (403(b) Plans)
Rules governing 403(b) plans used by teachers, hospital employees, and other public-sector workers.
Social Security COLA and Wage Base for 2026
Defines the 2026 Social Security taxable wage base ($184,500) used in self-employment tax calculations.
IRS Reference Pages
Official IRS overview pages and FAQs for each account type covered by our calculators.
See it in action
Numbers you can trust — in a calculator you can use.
All limits sourced above are wired directly into our calculators. No manual lookup required.