In addition to collecting taxes, issuing tax refunds, and performing audits, the IRS is tasked with enforcing the laws listed in the Internal Revenue Code

The Internal Revenue Code is also known as Title 26 of the US Code. It was enacted in 1925 and outlines income, estate, sales, payroll, and excise tax laws.

On July 1, 1862, the agency now known as the Internal Revenue Service was established and named the Bureau of Internal Revenue

It was created to collect the first-ever US income tax, which was created to help pay for the Civil War. After gaining their independence from Britain, Americans were skeptical about giving the federal government absolute power to collect federal income taxes. As a result, early US tax laws dictated that direct taxes, like income taxes, had to be directly apportioned to a state's population. The nation went back and forth on its federal tax laws multiple times. For instance, in 1872, the income tax from the Civil War was repealed. But it was revived in 1894, and then repealed again in 1895. In 1913, Congress passed the 16th Amendment, giving Congress the power to levy income taxes on individuals and corporations without apportioning the burden among the states in line with population, once and for all.

See a timeline of the IRS's history, including the introduction of standard deductions and the digitization of the filing process

The Commissioner of Internal Revenue was created in 1862 to take over federal tax collection after the President enacted a temporary income tax. That agency eventually became today's Internal Revenue Service.

Created in 1862, the IRS has a scandalous history

From Al Capone's tax evasion to corruption and bribery within the IRS, the government agency has had its fair share of scandals. This article details many of them, outlining corruption that reveals this seemingly boring agency as anything but.

Read more about how the IRS is organized

The Internal Revenue Service is led by a commissioner, who leads the IRS for a five-year term after being selected by the president of the United States. Under the commissioner, the IRS has multiple subdivisions that work on different tax groups, such as the Wage and Investment Division to handle individual wage earners.

It cost the IRS $0.36 to collect $100 in 2024

It costs the IRS a significant amount of money to do part of its job—collecting money. For instance, the Internal Revenue Service spent $16.1B to collect $4.7T in taxes in 2023.

The US officially adopted an income tax in 1913

The US first levied income taxes during the Civil War, but modern income taxes became an American fixture in 1913. Two years earlier, Congress passed the 16th Amendment to give the government the right to tax individuals' and businesses' income. The US still technically levies the same federal income tax now as it did then—though it's evolved.

The IRS may look at your social media if you're being audited

While some people cheat on their taxes, others evade paying them altogether. This article details methods the Internal Revenue Service uses to catch these people in the act, such as scanning social media, computer data analysis, and whistleblowers.

Over a century ago, fewer than 1% of Americans paid income taxes—but the cost of World War II prompted the federal government to greatly expand the number of people required to pay income taxes.

The IRS already has much of the data it asks Americans to report when filing their taxes

Americans spend more than 7.9 billion hours per year doing their taxes: It's notoriously time-consuming, requiring forms, deductions, and often third-party help. But here's the twist: The IRS already has much of the data it asks you to report. Americans still have to do the work themselves partly due to big tax prep companies that lobby to keep the status quo.

How tax laws helped the federal government catch mob bosses during Prohibition

The IRS arrested top mob bosses during Prohibition after the Supreme Court ruled illegally-made income could be taxed. The IRS's biggest catch was Al Capone, who was charged with tax evasion and sentenced to 11 years in prison. But Capone wasn't the only bootlegger the IRS nabbed for tax evasion during this era.

Individual income taxes are the federal government's primary revenue source, see a tracker that breaks down where the rest of the budget comes from

The US government historically makes nearly half of its total revenue last year from individual income taxes. But the US makes also makes money from a variety of other sources, including Medicare taxes and corporate income taxes. However, the federal government has run a deficit since 2001—reaching a peak of $3.13T in 2020.

Check out a list of 15 red flags that might result in an IRS audit

The Internal Revenue Service has audited less than 1% of all individual tax returns. If you're still worried about being audited, know that some people are more likely to be audited than others, such as people who make a lot of money and those who take large charitable deductions.

Learn how the US tax code works and why it's important

First published in 1926, the US Code is the official codification of federal statutes in the US. Title 26 of the US Code, for instance, lists all of the federal tax laws of the United States. A new edition is published every six years.

Half of Americans have an unfavorable opinion of the IRS, while 38% have a favorable view

From July 1 to July 7, 2024, Pew Research Center conducted a survey of 9,424 adults to gauge the public's attitudes about the federal government, including government agencies and departments. Of 13 agencies, 10 had net favorable ratings of 15 percentage points or more. Topping the list were the National Park Service (76% favorable), the US Postal Service (72%) and NASA (67%).

Since 1913, Americans have paid income taxes at varying rates

In the 2020s, the top marginal tax rate has floated around 37%, relatively lower than previous eras. Some have called for boosting the rate significantly to tax the highest earners.

Americans spend an average of $200 on tax preparation services like TurboTax and H&R Block

In 2025, about half of Americans were able to file taxes directly with the IRS for free. It was the second year of the agency's new program, which cuts out intermediaries. Though tax preparation has been free for many Americans, critics say tax companies upsell customers.

Before the 16th Amendment, US tax law required direct taxes to be directly apportioned to a state's population

Due to these requirements, the federal government could not impose many direct taxes. Direct taxes include property and income taxes, whereas indirect taxes include duties and excises.

Americans between the ages of 45 and 55 pay nearly 30% of all income taxes, paying an average tax rate of around 17%.

Immigration and Customs Enforcement handles immigration enforcement within the interior of the US

ICE operates inside the United States, enforcing immigration laws through investigations, arrests, detention, and deportation of individuals residing in the country illegally. This page provides an overview of the agency's mission, structure, and internal enforcement operations.

Capital gains taxes were first levied in the US in 1913

However, up until 1921, they were treated the same as ordinary income. Ever since then, rates have swung up and down.

Death taxes have helped fund wars since the 1860s

Death taxes date back to 700 BCE and were used in Ancient Rome and Ancient Egypt. In the US, they've been used to finance wars since the Civil War, and have been levied on both the estate and beneficiary. The estate tax created during WWI to help finance war efforts is still in effect today.

Revenue from tariffs goes to the US Treasury's general fund.

Roth IRAs were first introduced in the Taxpayer Relief Act of 1997

The Roth IRA is one of the most popular retirement accounts in the US. Nearly a quarter of Americans contributed to a Roth IRA in 2023. But this type of financial account hasn’t been around for that long.

Read why the information Americans have about our tax system might be misleading

For many, filing taxes can be complicated and overwhelming. Some argue that the tax system obscures certain aspects of the US tax code, making it difficult for taxpayers to accurately assess potential reforms.

The 16th Amendment paved the way for capital gains taxes

Ratified in 1913, the 16th Amendment paved the way for a far-reaching federal income tax and supercharged the country’s coffers. Before then, the US depended on import tariffs and so-called consumption taxes to raise revenue.

The Beatles' song 'Taxman' was inspired by Britain's tax structure.

Charting where federal revenue comes from

About 50 percent of federal revenue comes from individual income taxes, 7 percent from corporate income taxes, and another 36 percent from payroll taxes that fund social insurance programs. See breakdown in charts here.

Understanding the low corporate tax rate in the US

Corporate taxes, which make up roughly a third of the federal government's revenue, have been calculated using a flat 21% rate since the Tax Cuts & Jobs Act of 2017. The current rate is considered low both by historic standards (it averaged over 50% in the 1950s and 1960s) and compared to other countries.

Tariffs once fueled the US economy, historically serving as a primary source of revenue and a means to protect domestic industries.

About one dollar in every six that are owed to the federal government aren't paid each year

That adds up to close to $1T in what's known as the "tax gap." Read a breakdown on the main drivers of tax evasion (distinct from legal tax avoidance) in the US.

Hamilton's tax on whiskey sparked the first armed rebellion against US federal authority

As Treasury secretary, Alexander Hamilton designed an excise tax on whiskey that provoked violent resistance in western Pennsylvania. The Whiskey Rebellion ended when George Washington mobilized state militias under federal authority to enforce the law.

The Roth IRA was named after Senator William V. Roth, Jr.

The Roth IRA was established by Senator William Roth in 1997 as part of the Taxpayer Relief Act. Roth IRAs differ from traditional IRAs in that they allow individuals to invest after-tax income for retirement rather than pre-tax income.

What America's 1% pays in taxes, by state

In the US, the top 1% of earners contribute 45% of all personal income taxes collected nationwide. But not all states are created equal when it comes to income tax. Some states are more dependent on the 1% than others for tax revenue. SmartAsset recently examined IRS tax return data to determine exactly how much the top 1% of earners in each state paid in taxes. Find your state here.

How the federal income tax affected Prohibition

In the early 1900s, 30% to 40% of government tax revenue came from liquor, wine, and beer, a reliance that made Prohibition seem like a fiscal impossibility. But the passage of the federal income tax in 1913 changed the calculus, which helped allow the government to ban alcohol production and sales.

ICE was created in the aftermath of the 9/11 terrorist attacks

Created by the Homeland Security Act of 2002 following 9/11, ICE enforces federal immigration, customs, and trade laws under DHS. With over 20,000 staff across 400 global offices and an $8B budget, it focuses on detention, deportation, and cross-border criminal investigations.