The Internal Revenue Service (IRS) is the revenue service

Revenue service

A revenue service is a government agency responsible for the intake of government revenue, including taxes and sometimes non-tax revenue. Depending on the jurisdiction, revenue services may be charged with tax collection, investigation of tax evasion, or carrying out audits.-Revenue services by...

 of the United States federal government

Federal government of the United States

The federal government of the United States is the national government of the constitutional republic of fifty states that is the United States of America. The federal government comprises three distinct branches of government: a legislative, an executive and a judiciary. These branches and...

. The agency

Government agency

A government or state agency is a permanent or semi-permanent organization in the machinery of government that is responsible for the oversight and administration of specific functions, such as an intelligence agency. There is a notable variety of agency types...

 is a bureau of the Department of the Treasury

United States Department of the Treasury

The Department of the Treasury is an executive department and the treasury of the United States federal government. It was established by an Act of Congress in 1789 to manage government revenue...

, and is under the immediate direction of the Commissioner of Internal Revenue

Commissioner of Internal Revenue

The Commissioner of Internal Revenue is the head of the Internal Revenue Service , a bureau within the United States Department of the Treasury.The office of Commissioner was created by Congress by the Revenue Act of 1862...

. The IRS is responsible for collecting taxes and the interpretation and enforcement of the Internal Revenue Code

Internal Revenue Code

The Internal Revenue Code is the domestic portion of Federal statutory tax law in the United States, published in various volumes of the United States Statutes at Large, and separately as Title 26 of the United States Code...

.
The IRS has its Headquarters office in the greater Washington, D.C.

Washington, D.C.

Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....

 area, and in particular does most of its computer programming

Computer programming

Computer programming is the process of designing, writing, testing, debugging, and maintaining the source code of computer programs. This source code is written in one or more programming languages. The purpose of programming is to create a program that performs specific operations or exhibits a...

 in Maryland

Maryland

Maryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east...

. It currently operates five service centers around the country (in Austin, TX; Cincinnati, OH; Fresno, CA; Kansas City, MO; and Ogden, UT), at which returns

Tax return (United States)

Tax returns in the United States are reports filed with the Internal Revenue Service or with the state or local tax collection agency containing information used to calculate income tax or other taxes...

 sent by mail

United States Postal Service

The United States Postal Service is an independent agency of the United States government responsible for providing postal service in the United States...

 are received.