| State | Filing Deadline | Primary | Runoff |
|---|---|---|---|
| Alabama | Jan. 13 | March 13 | April 24 |
| Alaska | June 1 | Aug. 28 | |
| Arizona | May 30 | Aug. 28 | |
| Arkansas | March 1 | Pending | Pending |
| California | March 9 | June 5 | |
| Colorado | March 31 | June 26 | |
| Connecticut | Pending | Aug. 14 | |
| Delaware | July 10 | Sept. 11 | |
| District of Columbia | Jan. 4 | April 3 | |
| Florida | June 8 | Aug. 14 | |
| Georgia | May 25 | July 13 | Aug. 21 |
| Hawaii | June 5 | Aug. 11 | |
| Idaho | March 9 | May 15 | |
| Illinois | Dec. 5, 2011 | March 20 | |
| Indiana | Feb. 10 | May 8 | |
| Iowa | March 16 | June 5 | |
| Kansas | June 1* | Aug. 7 | |
| Kentucky | Jan. 31 | May 22 | |
| Louisiana | Aug. 17 | Nov. 6 | Dec. 1 |
| Maine | March 15 | June 12 | |
| Maryland | Jan. 11 | April 3 | |
| Massachusetts | June 5 | Sept. 18** | |
| Michigan | May 15 | Aug. 7 | |
| Minnesota | June 5 | Aug. 14 | |
| Mississippi | Jan. 13 | March 13 | April 3 |
| Missouri | March 27 | Aug. 7 | |
| Montana | March 12 | June 5 | |
| Nebraska | Feb. 15*** | May 15 | |
| Nevada | March 16 | June 12 | |
| New Hampshire | June 15 | Sept. 11 | |
| New Jersey | Pending | June 5 | |
| New Mexico | Feb. 14 | June 5 | |
| New York | Pending | Pending | |
| North Carolina | Feb. 29 | May 8 | July 17 |
| North Dakota | April 13 | June 12 | |
| Ohio | Dec. 7, 2011 (Senate), March 14 (House) | March 6 (Senate), June 12 (House) | |
| Oklahoma | April 13 | June 26 | Aug. 28 |
| Oregon | March 6 | May 15 | |
| Pennsylvania | Feb. 14 | April 24** | |
| Rhode Island | June 27 | Sept. 11 | |
| South Carolina | March 30 | June 12 | June 26 |
| South Dakota | March 27 | June 5 | June 26 |
| Tennessee | Feb. 16 | Aug. 2 | |
| Texas | Dec. 12, 2011 | March 6 | May 22 |
| Utah | March 15 | June 26 | |
| Vermont | June 14 | Aug. 28 | |
| Virginia | March 29 | June 12 | |
| Washington | May 18 | Aug. 7 | |
| West Virginia | Jan. 28 | May 8 | |
| Wisconsin | June 1 | Pending | |
| Wyoming | June 1 | Aug. 21 |
All dates are in 2012 unless otherwise noted. Source: Federal Election Commission, state boards of election * Filing deadline will be moved to June 11 if redistricting is finished after May 10. ** Date is tentative or likely to change. *** Filing deadline is March 1 for nonincumbents.