What Is The IRS And What Does It Do?

The Internal Revenue Service, or IRS, is the division of the U.S. Treasury Department responsible for assessing and collecting tax revenue from individuals and businesses.

What is the IRS?

The IRS we know today dates back to 1862 when President Abraham Lincoln, looking to raise money to pay for the Civil War, signed a law that created the first income tax and established a Commissioner of Internal Revenue.

The IRS has gone through several changes, reorganizations and modernizations over the years, including being renamed and placed under the authority of the Treasury Department.

The mission of the IRS is to carry out U.S. tax laws. It assesses and collects taxes, helps taxpayers understand and meet their tax responsibilities and enforces tax laws to ensure everyone pays their fair share.

What does the IRS do?

The IRS has many responsibilities, which can be broken down into three main categories: tax collection, taxpayer services and tax law enforcement.

Collecting taxes

One of the most important responsibilities of the IRS is to assess and collect taxes on behalf of the federal government. The IRS collected nearly $4.7 trillion in gross taxes in fiscal year 2023, including income taxes, employment taxes, business income taxes, excise taxes and estate and gift taxes.

Along with collecting taxes, the IRS is responsible for issuing tax refunds, which an individual or business usually receives as a result of overpaying taxes.

Providing services to taxpayers

Another IRS responsibility is providing services to taxpayers year-round — not just at tax time. The bureau provides assistance in a variety of different ways.

In fiscal year 2023, the IRS helped nearly 60.3 million taxpayers who called a helpline or visited an IRS office. There were also almost 881 million visits to the IRS website.

Enforcing tax laws

Finally, the IRS is responsible for enforcing tax laws. The IRS looks for taxpayers who have underpaid their taxes, whether as a result of a math error or criminal activity. These audits usually take the form of written correspondence or in-person visits.

For all returns filed from 2013 through 2021, the IRS examined 0.44 percent of individual tax returns and 0.74 percent of corporate tax returns. The IRS completed 2,584 criminal investigations in 2023.

Who operates the IRS?

The IRS is overseen by a commissioner who is nominated by the president and confirmed by the Senate. The commissioner serves a five-year term. The other appointed position within the agency is the IRS chief counsel.

Leadership at the IRS is currently in flux. Danny Werfel, who had been the commissioner since 2023, resigned in January 2025. Following Werfel’s departure, Treasury Secretary Scott Bessent announced an acting IRS commissioner, who subsequently retired, and a replacement. President Donald Trump has nominated Billy Long as the next commissioner, though as of mid-March, the U.S. Senate had yet to confirm Long.

In addition to being under the authority of the IRS commissioner, the agency is also overseen by the IRS Oversight Board. The board was created to provide long-term guidance and expertise to help the IRS best meet the needs of taxpayers.

How you may interact with the IRS

If you’re a U.S. taxpayer, you have dealt with the IRS in one way or another. The most common way most people interact with the IRS is by paying their individual income taxes. Regardless of whether you use tax software or a financial professional to file your taxes, your return eventually ends up with the IRS. And if you qualify for a federal tax refund, it’s the IRS that you receive it from.

It was also the IRS that issued three different Economic Impact Payments (known as stimulus checks) between 2020 and 2021. These payments were sent either as a check or a direct deposit to taxpayers.

A less desirable interaction you may have with the IRS is an audit. An audit can occur if you fail to report income you earned throughout the year, make a math error on your tax return or claim too many business or personal tax deductions, among other reasons. With the most simple audit, the IRS may mail you a letter to request more information from you. The IRS may also conduct a field audit, which is a full audit of your tax return and is often done in a face-to-face setting.

The most common ways most taxpayers interact with the IRS is by visiting its website or by speaking with an IRS representative to get tax questions answered.

There are a variety of reasons you might need to contact the IRS, including asking tax-filing questions, inquiring about a tax refund, paying your tax bill and more.

The simplest way to get answers to your tax questions is using the interactive tax assistant on the IRS website, where you can find answers to a wide range of tax questions. If you need more personalized help or have a question that can’t be answered with the interactive tax assistant, you can call one of the many IRS phone numbers. That said, given recent staffing cuts at the agency, you may experience longer than average wait times. Here are the numbers for a variety of tax topics:

Before calling one of the IRS phone numbers, be sure to have your Social Security number or Individual Taxpayer Identification Number (ITIN), birth date, filing status, previous correspondence and the tax return you’re calling about. This information will help the IRS representative to identify you and best answer your questions.