Glossary
IRS
The Internal Revenue Service, the US federal agency that collects taxes and enforces federal tax law, including the rules on retirement accounts and investment income.
Updated September 15, 2026
The IRS, or Internal Revenue Service, is the federal agency that collects taxes and enforces tax law in the United States. It is a bureau of the Treasury Department. Congress writes the tax laws; the IRS administers them, processing returns, paying refunds and auditing some filers.
The IRS announces annual retirement contribution limits (for 2026, the employee 401(k) limit is $24,500), applies the rules on which dividends are qualified, taxed at lower rates than ordinary income, and treats virtual currency as property, so selling it can create a gain or loss you report. Your bank or broker generally reports interest, dividends and sales to the IRS on 1099 forms.
The IRS also issues Individual Taxpayer Identification Numbers to people not eligible for a Social Security number. Tax rules depend on your own situation, and a licensed tax professional can help.
Related terms
Used in these lessons
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How a 401(k) works
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Bank accounts and emergency savings before investing
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What a cryptocurrency is
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Gold and other precious metals as investments
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How investment income is taxed in the US
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IRAs: traditional and Roth
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Social Security numbers and ITINs
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Your first weeks: an address, a phone line and the lights on
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Emergency care and the bills that come after
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How everyday law works, and where to get help
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From Mexican bank deposits and the IPAB to US savings accounts and CDs
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From CDTs and Fogafín to savings accounts and CDs in the United States
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From poupança and CDBs to US savings accounts and CDs
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From Tesouro Direto to US Treasuries
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From CETES to US Treasury bills
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From Colombian pensions to Social Security, 401(k)s and IRAs
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From INSS and previdência privada to Social Security, 401(k)s and IRAs
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From Afore and IMSS to Social Security, 401(k)s and IRAs
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Ways people pay down debt
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How to spot money scams and pressure selling
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Reading a US paycheck
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Filing your first US tax return
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The tax forms investors receive
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Money in two countries: the US tax rules to know exist
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Asset allocation and rebalancing
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Dividends: how companies share profits with shareholders
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Health savings accounts (HSAs)
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Rollovers when you change jobs
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Ways to hold gold
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TIPS and I bonds: Treasury securities that adjust for inflation
How this definition was made
- Written by an AI model (Claude) following Teloria's editorial standard.
- Every factual claim was checked by a separate AI fact-check against official US government and regulator sources.
Official sources consulted
- home.treasury.gov · /about/bureaus
- irs.gov · /newsroom/401k-limit-increases-to-24500-for-2026-ira-limit-increases-to-7500
- irs.gov · /about-irs/the-agency-its-mission-and-statutory-authority
- irs.gov · /taxtopics/tc404
- irs.gov · /individuals/international-taxpayers/frequently-asked-questions-on-virtual-currency-transactions
- irs.gov · /tin/itin/individual-taxpayer-identification-number-itin