About About401K

About401K.com is an independent, plain-English reference for 401(k) rules: contribution limits, withdrawals, loans, vesting, and rollovers. We are not a brokerage, an advisor, or a plan provider. Every rule we publish cites its primary source (the Internal Revenue Code, IRS notices, or Department of Labor guidance) and shows the date it was last verified.

What this site is

The 401(k) is governed by some of the most confusing rules in personal finance, and most answers online are either vague or outdated. This site does one thing: it states the current rules precisely, in plain English, with the numbers attached. Established in 2012, About401K was rebuilt and re-verified in 2026 against current law, including SECURE 2.0.

How we keep content accurate

• Primary sources only. Rules are drawn from the IRC, IRS guidance (including the annual cost-of-living notice), Treasury regulations, and Department of Labor materials, not from other blogs.
• Dated verification. Each page shows when it was last updated. When the IRS publishes new limits each fall, we update every affected page within days.
• Plan-document honesty. Many 401(k) rules are set by your employer’s plan document, not by law. Where that’s true, we say so instead of pretending one answer fits every plan.

What we are not

Nothing here is individualized investment, tax, or legal advice. Your plan document and your own tax situation control; for decisions involving significant money, consult a qualified professional (a CPA, CFP®, or ERISA attorney).

How we make money

The site is supported by advertising and, on clearly marked pages, affiliate partnerships. Partners never influence what the rules pages say. The rules are the rules. See our full disclosure.

Contact

Corrections are welcome and get priority handling. If a number or rule on this site is wrong or outdated, tell us and we will verify and fix it.

Last updated September 25, 2026