Iowa

U.S. Marshals Service offices are based on the organizational structure of the Federal District Court system. Iowa is divided into two judicial districts that are referred to as the Northern and Southern Districts of Iowa.

	Northern District of Iowa: The Northern District comprises the counties of Allamakee, Benton, Black Hawk, Bremer, Buchanan, Buena Vista, Butler, Calhoun, Carroll, Cedar, Cerro Gordo, Cherokee, Chickasaw, Clay, Clayton, Crawford, Delaware, Dickinson, Dubuque, Emmet, Fayette, Floyd, Franklin, Grundy, Hamilton, Hancock, Hardin, Howard, Humboldt, Ida, Iowa, Jackson, Jones, Kossuth, Linn, Lyon, Mitchell, Monona, O'Brien, Osceola, Palo Alto, Plymouth, Pocahontas, Sac, Sioux, Tama, Webster, Winnebago, Winneshiek, Woodbury, Worth and Wright. Court for the Northern District is held in Cedar Rapids, Dubuque, Fort Dodge, Mason City, Sioux City, and Waterloo.

	Southern District of Iowa: The Southern District comprises the counties of Adair, Adams, Appanoose, Audubon, Boone, Cass, Clarke, Clinton, Dallas, Davis, Decatur, Des Moines, Fremont, Greene, Guthrie, Harrison, Henry, Jasper, Jefferson, Johnson, Keokuk, Lee, Louisa, Lucas, Madison, Mahaska, Marion, Marshall, Mills, Monroe, Montgomery, Muscatine, Page, Polk, Pottawattamie, Poweshiek, Ringgold, Scott, Shelby, Story, Taylor, Union, Van Buren, Wapello, Warren, Washington and Wayne. Court for the Southern Division is held in Des Moines, Council Bluffs, Creston, Davenport, Keokuk and Ottumwa.
The organizational structure of the district can be found in the United States Code Title 28, Part I, Chapter 5, Section 95.