Seniority in the United States Senate is valuable as it confers a number of benefits and is based on length of continuous service, with ties broken by a series of factors. Customarily, the terms "senior senator" and "junior senator" are used to distinguish the two senators representing a particular state.

Benefits of seniority

The United States Constitution does not mandate differences in rights or power, but Senate rules give more power to senators with more seniority. Generally, senior senators will have more power, especially within their own caucuses. In addition, by custom, senior senators from the president's party control federal patronage appointments in their states.

The president pro tempore of the Senate is traditionally the most senior member of the majority party.

There are several benefits, including the following:

  • Senators are given preferential treatment in choosing committee assignments based on seniority. Seniority on a committee is based on length of time serving on that committee, which means a senator may rank above another in committee seniority but be more junior in the full Senate. Although the committee chairmanship is an elected position, it is traditionally given to the most senior senator of the majority party serving on the committee, and not already holding a conflicting position such as chairmanship of another committee. The ranking member of a committee (called the vice-chairman in some select committees) is elected in the same way.
  • Greater seniority enables a senator to choose a desk closer to the front of the Senate Chamber.
  • Senators with higher seniority may choose to move into better office space as those offices are vacated.
  • Seniority determines the ranking in the United States order of precedence although other factors, such as being a former President or First Lady, can place an individual higher in the order of precedence.

Determining the beginning of a term

A term does not necessarily coincide with the date the Senate convenes or when the new Senator is sworn in. In the case of Senators first elected in a general election for the upcoming Congress, their terms begin on the first day of the new Congress. Since 1935, that means January 3 of odd-numbered years. The seniority date for an appointed senator is the date of the appointment, not necessarily the date of taking the oath of office. In the case of Senators taking vacant seats in special elections, the term begins on Election Day. However, in both of these cases, if the incoming Senator is a Member of the U.S. House of Representatives at the time, he/she must resign from the House before her/his term in the Senate begins.

Determining length of seniority

A senator's seniority is primarily determined by length of continuous service; for example, a senator who has served for 12 years is more senior than one who has served for 10 years. Because several new senators usually join at the beginning of a new Congress, seniority is determined by prior federal or state government service. These tiebreakers in order are:[3]

  1. Former Senator
  2. Former Vice President
  3. Former House member
  4. Former Cabinet secretary
  5. Former state Governor
  6. Population of state based on the most recent census when the senator took office
  7. Alphabetical by last name (in case two senators came from the same state on the same day and have identical credentials)

When more than one senator has served in the same previous role, length of time in that prior office is used to break the tie. For instance, Ben Cardin, Bernie Sanders, Sherrod Brown, Bob Casey, Bob Corker, Claire McCaskill, Amy Klobuchar, Sheldon Whitehouse and Jon Tester took office on January 3, 2007, and the first three senators mentioned had previously served in the House of Representatives. Cardin, having served 20 years, is more senior than Sanders, who served 16, in turn is more senior than Brown who served 14 years. Casey is more senior than Corker because as of the 2000 census, Pennsylvania's population outranks that of Tennessee's, McCaskill is more senior than Klobuchar because Missouri's population outranked that of Minnesota, and the latter is more senior than Whitehouse because the latter's home state outranked Rhode Island's population, meanwhile Tester's home state of Montana had the least population amongst the freshmen class of 2006, thus he was ranked 100 in seniority when the 110th Congress convened.

Current seniority list

Only relevant factors are listed below. For senators whose seniority is based on their state's respective population, the state population ranking is given as determined by the relevant United States Census current at the time they first took their seat.[2][3][4][2]

   Republican R (52)        Democratic D (46)        Independent I (2)

Seniority dateFirst tie-breakerSecond tie-breakerCommittee and leadership positions
11692Leahy, PatrickPatrick Leahy
January 3, 1975Ranking Member: Appropriations
President pro tempore emeritus
21708Hatch, OrrinOrrin Hatch
January 3, 1977President pro tempore
Chair: Finance
31719Cochran, ThadThad Cochran
December 27, 1978Chair: Appropriations
41745Grassley, ChuckChuck Grassley
January 3, 1981Chair: Judiciary
51766McConnell, MitchMitch McConnell
January 3, 1985Majority Leader
61775Shelby, RichardRichard Shelby
January 3, 1987Former Representative (8 years)Chair: Rules
71777McCain, JohnJohn McCain
Former Representative (4 years)Chair: Armed Services
81801Feinstein, DianneDianne Feinstein
November 4, 1992Ranking Member: Judiciary
91810Murray, PattyPatty Murray
January 3, 1993Ranking Member: HELP
Assistant Minority Leader
101816Inhofe, JimJim Inhofe
November 16, 1994 
111827Wyden, RonRon Wyden
February 6, 1996Ranking Member: Finance
121830Roberts, PatPat Roberts
January 3, 1997Former Representative (16 years)Chair: Agriculture
131831Durbin, DickDick Durbin
Former Representative (14 years)Minority Whip
141835Reed, JackJack Reed
D-Rhode Island
Former Representative (6 years)Ranking Member: Armed Services
151842Collins, SusanSusan Collins
Maine 38th in population (1990)Chair: Aging
161843Enzi, MikeMike Enzi
Wyoming 50th in population (1990)Chair: Budget
171844Schumer, ChuckChuck Schumer
D-New York
January 3, 1999Former Representative (18 years)Minority Leader
181846Crapo, MikeMike Crapo
Former Representative (6 years)Chair: Banking
191854Nelson, BillBill Nelson
January 3, 2001Former Representative (12 years)Ranking Member: Commerce
201855Carper, TomTom Carper
Former Representative (10 years)Ranking Member: Environment
211856Stabenow, DebbieDebbie Stabenow
Former Representative (4 years)Ranking Member: Agriculture
Democratic Policy Committee Chair
221859Cantwell, MariaMaria Cantwell
Former Representative (2 years)Ranking Member: Energy
231873Murkowski, LisaLisa Murkowski
December 20, 2002 Chair: Energy
241867Graham, LindseyLindsey Graham
R-South Carolina
January 3, 2003Former Representative 
251869Alexander, LamarLamar Alexander
Former Cabinet memberChair: HELP
261871Cornyn, JohnJohn Cornyn
Majority Whip
271876Burr, RichardRichard Burr
R-North Carolina
January 3, 2005Former Representative (10 years)Chair: Intelligence
281879Thune, JohnJohn Thune
R-South Dakota
Former Representative (6 years)Chair: Commerce
Republican Conference Chair
291880Isakson, JohnnyJohnny Isakson
Former Representative (5 yrs., 10 mos.)Chair: Veterans' Affairs
Chair: Ethics
301885Menendez, BobBob Menendez
D-New Jersey
January 17, 2006 
311886Cardin, BenBen Cardin
January 3, 2007Former Representative (20 years)Ranking Member: Foreign Relations
321887Sanders, BernieBernie Sanders
Former Representative (16 years)Ranking Member: Budget
331888Brown, SherrodSherrod Brown
Former Representative (14 years)Ranking Member: Banking
341890Casey Jr., BobBob Casey Jr.
Pennsylvania 6th in population (2000)Ranking Member: Aging
351891Corker, BobBob Corker
Tennessee 16th in population (2000)Chair: Foreign Relations
361892McCaskill, ClaireClaire McCaskill
Missouri 17th in population (2000)Ranking Member: Homeland Security
371893Klobuchar, AmyAmy Klobuchar
Minnesota 21st in population (2000)Ranking Member: Rules
381894Whitehouse, SheldonSheldon Whitehouse
D-Rhode Island
Rhode Island 43rd in population (2000)
391895Tester, JonJon Tester
Montana 44th in population (2000)Ranking Member: Veterans' Affairs
401896Barrasso, JohnJohn Barrasso
June 22, 2007Chair: Environment
Republican Policy Committee Chair
411897Wicker, RogerRoger Wicker
December 31, 2007
421899Udall, TomTom Udall
D-New Mexico
January 3, 2009Former RepresentativeVice Chair: Indian Affairs
431901Shaheen, JeanneJeanne Shaheen
D-New Hampshire
Former Governor (6 years)Ranking Member: Small Business
441902Warner, MarkMark Warner
Former Governor (4 years)Vice Chair: Intelligence
Democratic Caucus Vice Chair
451903Risch, JimJim Risch
Former Governor (7 months)Chair: Small Business
461905Merkley, JeffJeff Merkley
471909Bennet, MichaelMichael Bennet
January 21, 2009
481910Gillibrand, KirstenKirsten Gillibrand
D-New York
January 26, 2009
491911Franken, AlAl Franken
July 7, 2009
501916Manchin, JoeJoe Manchin
D-West Virginia
November 15, 2010Former Governor
511917Coons, ChrisChris Coons
Vice Chair: Ethics
521919Blunt, RoyRoy Blunt
January 3, 2011Former Representative (14 years)Missouri 17th in population (2000)Republican Conference Vice Chair
531920Moran, JerryJerry Moran
Kansas 33rd in population (2000)
541921Portman, RobRob Portman
Former Representative (12 years)
551922Boozman, JohnJohn Boozman
Former Representative (10 years)
561923Toomey, PatPat Toomey
Former Representative (6 years)
571924Hoeven, JohnJohn Hoeven
R-North Dakota
Former GovernorChair: Indian Affairs
581925Rubio, MarcoMarco Rubio
Florida 4th in population (2000)
591926Johnson, RonRon Johnson
Wisconsin 20th in population (2000)Chair: Homeland Security
601927Paul, RandRand Paul
Kentucky 25th in population (2000)
611928Blumenthal, RichardRichard Blumenthal
Connecticut 29th in population (2000)
621929Lee, MikeMike Lee
Utah 34th in population (2000)
631931Heller, DeanDean Heller
May 9, 2011
641932Schatz, BrianBrian Schatz
December 26, 2012
651933Scott, TimTim Scott
R-South Carolina
January 2, 2013
661934Baldwin, TammyTammy Baldwin
January 3, 2013Former Representative (14 years)Democratic Caucus Secretary
671935Flake, JeffJeff Flake
Former Representative (12 years)
681936Donnelly, JoeJoe Donnelly
Former Representative (6 years)Indiana 15th in population (2010)
691937Murphy, ChrisChris Murphy
Connecticut 29th in population (2010)
701938Hirono, MazieMazie Hirono
Hawaii 40th in population (2010)
711939Heinrich, MartinMartin Heinrich
D-New Mexico
Former Representative (4 years) 
721940King, AngusAngus King
Former Governor (8 years)
731941Kaine, TimTim Kaine
Former Governor (4 years)
741942Cruz, TedTed Cruz
Texas 2nd in population (2010)
751943Warren, ElizabethElizabeth Warren
Massachusetts 14th in population (2010)Democratic Caucus Vice Chair
761944Fischer, DebDeb Fischer
Nebraska 38th in population (2010)
771945Heitkamp, HeidiHeidi Heitkamp
D-North Dakota
North Dakota 48th in population (2010)
781948Markey, EdEd Markey
July 16, 2013
791949Booker, CoryCory Booker
D-New Jersey
October 31, 2013
801951Capito, Shelley MooreShelley Moore Capito
R-West Virginia
January 3, 2015Former Representative (14 years)
811952Peters, GaryGary Peters
Former Representative (6 years)Michigan 8th in population (2010)
821953Cassidy, BillBill Cassidy
Louisiana 25th in population (2010)
831954Gardner, CoryCory Gardner
Former Representative (4 years)Colorado 22nd in population (2010)NRSC Chair
841955Lankford, JamesJames Lankford
Oklahoma 28th in population (2010)
851956Cotton, TomTom Cotton
Former Representative (2 years)Arkansas 32nd in population (2010)
861957Daines, SteveSteve Daines
Montana 44th in population (2010)
871958Rounds, MikeMike Rounds
R-South Dakota
Former Governor
881959Perdue, DavidDavid Perdue
Georgia 9th in population (2010)
891960Tillis, ThomThom Tillis
R-North Carolina
North Carolina 10th in population (2010)
901961Ernst, JoniJoni Ernst
Iowa 30th in population (2010)
911962Sasse, BenBen Sasse
Nebraska 38th in population (2010)
921963Sullivan, DanDan Sullivan
Alaska 47th in population (2010)
931964Van Hollen, ChrisChris Van Hollen
January 3, 2017Former Representative (14 years)DSCC Chair
941965Young, ToddTodd Young
Former Representative (6 years)
951966Duckworth, TammyTammy Duckworth
Former Representative (4 years)
961967Hassan, MaggieMaggie Hassan
D-New Hampshire
Former Governor
971968Harris, KamalaKamala Harris
California 1st in population (2010)
981969Kennedy, John NeelyJohn Neely Kennedy
Louisiana 25th in population (2010)
991970Cortez Masto, CatherineCatherine Cortez Masto
Nevada 35th in population (2010)
1001971Strange, LutherLuther Strange
February 9, 2017

Seniority dateFirst tie-breakerSecond tie-breakerCommittee and leadership positions

See also


  1. The seniority date for an appointed senator is the date of the appointment, not necessarily the date of taking the oath of office. See , above.
  2. Richard Shelby's 1994 party change did not break his service or seniority.
  3. Maria Cantwell (#22) is the Senate's most senior junior senator.
  4. John Cornyn's predecessor, Phil Gramm, resigned early, effective November 30, 2002, so that Senator-elect Cornyn could take office early, and move into Gramm's office suite in order to begin organizing his staff. Cornyn did not, however, gain seniority, owing to a 1980 Rules Committee policy that no longer gave seniority to senators who entered Congress early for the purpose of gaining advantageous office space.
  5. Although Sanders was a candidate for the Democratic nomination for President in 2016, and has voted with the Democratic Party for organizational purposes throughout his time in Congress, he has never been a Democratic Senator.
  6. Al Franken was elected to the Senate term that began January 3, 2009, but, due to legal challenges, was not sworn in until July 7, 2009 (see United States Senate election in Minnesota, 2008 for more details). His seniority date is based on the date he was sworn in.
  7. Bill Cassidy (#82) is the Senate's most junior senior senator.