Average Years of Service for Members of the Senate and House of Representatives, First - 111th Congresses

Matthew Eric Glassman
Analyst on the Congress

The average tenure of Members of the Senate and House of Representatives at the beginning of each Congress has varied substantially since 1789. The purpose of this report is to provide a Congress-by-Congress summary of the average years of service for Senators and Representatives for the First through the 111th Congresses. The information for each Congress reflects only the Members entitled to be seated at the beginning of that Congress. 

The report contains a brief summary of some of the explanations by political scientists and others for the various changes in the average years of service. The information should be read with the understanding that the length of congressional careers has also depended on the number of congressional retirements as well as the success rates for those incumbents who have sought reelection. For information on the number of freshmen elected to Congress, refer to CRS Report R41283, First-Term Members of the House of Representatives and Senate, 64th – 111th Congresses, by Jennifer E. Manning, Parker H. Reynolds, and R. Eric Petersen. 

The average years of service for Members of the 111th Congress, as of January 3, 2009, when the Congress convened was 11.0 years for the House and 12.9 years for the Senate. This is a record for both the House and the Senate.


Date of Report: June 14, 2010
Number of Pages: 11
Order Number: RL32648
Price: $29.95

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