United States senators are conventionally ranked by the length of their tenure in the Senate. The senator in each U.S. state with the longer time in office is known as the senior senator; the other is the junior senator. This convention has no official standing, though seniority confers several benefits, including preference in the choice of committee assignments, physical offices, and the member's desk assignment. When senators have been in office for the same length of time, a number of tiebreakers, including previous offices held, are used to determine seniority. By tradition, the longest serving senator of the majority party is named president pro tempore of the Senate, the second-highest office in the Senate and the third in the line of succession to the presidency of the United States.

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.

There are several benefits, including the following:

  • Traditionally, the most senior member of the majority party is named president pro tempore of the Senate.
  • 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.

Determining the beginning of a term

The beginning of an appointment does not always coincide with the date the Senate convenes or when the new senator is sworn in.

General elections

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. For most of American history this was March 4 of odd-numbered years, but effective from 1935 the 20th Amendment moved this to January 3 of odd-numbered years.

Run-off elections and special elections

In the case of senators elected in a run-off election occurring after the commencement of a new term, or a special election, their seniority date will be the date they are sworn in and not the first day of that Congress. A senator may be simultaneously elected to fill a term in a special election and elected to the six-year term which begins on the upcoming January 3. Their seniority is that of someone chosen in a special election.

Appointments

The seniority date for an appointed senator is usually the date of the appointment,[citation needed] although the actual term does not begin until they take the oath of office. An incoming senator who holds another office, including membership in the U.S. House of Representatives, must resign from that office before becoming a senator. In the 1970s, some senators would resign a few days or weeks early so that their successor may be appointed to the seat and have greater seniority than other freshmen. In 1980, party rule changes removed seniority advantages in such cases.

Determining length of seniority

A senator's seniority is primarily determined by length of continuous service; for example, a senator who has served for twelve years is more senior than one who has served for ten years. Because several new senators usually join at the beginning of a new Congress, seniority is further determined by prior federal or state government service and, if necessary, the amount of time spent in the tiebreaking office. These tiebreakers in order are:

  1. Former senator
  2. Former vice president of the United States
  3. Former member of the United States House of Representatives
  4. Former member of the Cabinet of the United States
  5. Former state governor
  6. Population of state based on the most recent census when the senator took office

When more than one senator had such office, its length of time is used to break the tie. For instance, Jerry Moran, John Boozman, John Hoeven, Ron Johnson, Rand Paul, Richard Blumenthal, and Mike Lee all took office on January 3, 2011. The first two senators mentioned had served in the House of Representatives: Moran had served for fourteen years and Boozman for nine. As a former governor, Hoeven was ranked immediately after the former House members. The rest were ranked by population as of the 2000 census. These ranked from 27th to 33rd in seniority when the 119th United States Congress convened.

If two senators are tied on all criteria, the one whose surname comes first alphabetically is considered the senior senator. This happened with Jon Ossoff and Raphael Warnock, both of Georgia, who were sworn in on January 20, 2021. Because they were both newly elected senators from the same state, with no prior government service, no other tie-breaking criteria could be used. The Senate's official records, as well as the Democratic Caucus, thus consider Ossoff, whose name comes first alphabetically and who had been elected to a full six-year term, as the senior senator.

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 that they began service.

The most senior senators by class are Maria Cantwell (D-Washington) from Class 1, Mitch McConnell (R-Kentucky) from Class 2, and Chuck Grassley (R-Iowa) from Class 3. Cantwell is the most senior senator from her class while being the junior senator from her state.

Republican (53) Democratic (45) Independent (2)

Current rankHistorical rankSenatorPartyStateSeniority dateOther factorsCommittee and leadership positions
11743Chuck GrassleyRepublicanIowaJanuary 3, 1981President pro tempore Chair: Judiciary
21766Mitch McConnellKentuckyJanuary 3, 1985Chair: Rules
31812Patty MurrayDemocraticWashingtonJanuary 3, 1993President pro tempore emerita Vice Chair: Appropriations
41827Ron WydenOregonFebruary 6, 1996Ranking Member: Finance
51831Dick DurbinIllinoisJanuary 3, 1997Former House member (14 years)Senate Minority Whip Ranking Member: Judiciary
61835Jack ReedRhode IslandFormer House member (6 years)Ranking Member: Armed Services
71842Susan CollinsRepublicanMaineChair: Appropriations
81844Chuck SchumerDemocraticNew YorkJanuary 3, 1999Former House member (18 years)Senate Minority Leader
91846Mike CrapoRepublicanIdahoFormer House member (6 years)Republican Chief Deputy Whip Chair: Finance
101859Maria CantwellDemocraticWashingtonJanuary 3, 2001Ranking Member: Commerce
111867John CornynRepublicanTexasDecember 2, 2002Chair: Narcotics Caucus
121868Lisa MurkowskiAlaskaDecember 20, 2002Chair: Indian Affairs
131870Lindsey GrahamSouth CarolinaJanuary 3, 2003Chair: Budget
141879John ThuneSouth DakotaJanuary 3, 2005Senate Majority Leader
151887Bernie SandersIndependentVermontJanuary 3, 2007Former House memberChair: Democratic Outreach Committee Ranking Member: HELP
161893Amy KlobucharDemocraticMinnesotaMinnesota 21st in population (2000)Chair: Democratic Steering and Policy Committee Ranking Member: Agriculture
171894Sheldon WhitehouseRhode IslandRhode Island 43rd in population (2000)Ranking Member: Environment Ranking Member: Narcotics Caucus
181896John BarrassoRepublicanWyomingJune 22, 2007Senate Majority Whip
191897Roger WickerMississippiDecember 31, 2007Chair: Armed Services
201901Jeanne ShaheenDemocraticNew HampshireJanuary 3, 2009Former governor (6 years)Ranking Member: Foreign Relations
211902Mark WarnerVirginiaFormer governor (4 years)Vice Chair: Democratic Caucus Vice Chair: Intelligence
221903Jim RischRepublicanIdahoFormer governor (7 months)Chair: Foreign Relations
231905Jeff MerkleyDemocraticOregonRanking Member: Budget
241909Michael BennetColoradoJanuary 21, 2009
251910Kirsten GillibrandNew YorkJanuary 26, 2009Chair: DSCC Ranking Member: Aging
261917Chris CoonsDelawareNovember 15, 2010Vice Chair: Ethics
271920Jerry MoranRepublicanKansasJanuary 3, 2011Former House member (14 years)Chair: Veterans' Affairs
281922John BoozmanArkansasFormer House member (9 years)Chair: Agriculture
291924John HoevenNorth DakotaFormer governor
301926Ron JohnsonWisconsinWisconsin 20th in population (2000)
311927Rand PaulKentuckyKentucky 25th in population (2000)Chair: Homeland Security
321928Richard BlumenthalDemocraticConnecticutConnecticut 29th in population (2000)Ranking Member: Veterans' Affairs
331929Mike LeeRepublicanUtahUtah 34th in population (2000)Chair: Energy
341932Brian SchatzDemocraticHawaiiDecember 26, 2012Democratic Chief Deputy Whip Deputy Secretary: Democratic Caucus Vice Chair: Indian Affairs
351933Tim ScottRepublicanSouth CarolinaJanuary 2, 2013Chair: NRSC Chair: Banking
361934Tammy BaldwinDemocraticWisconsinJanuary 3, 2013Former House member (14 years)Secretary: Democratic Caucus
371937Chris MurphyConnecticutFormer House member (6 years); Connecticut 29th in population (2010)Deputy Secretary: Democratic Caucus
381938Mazie HironoHawaiiFormer House member (6 years); Hawaii 40th in population (2010)
391939Martin HeinrichNew MexicoFormer House member (4 years)Ranking Member: Energy
401940Angus KingIndependentMaineFormer governor (8 years)
411941Tim KaineDemocraticVirginiaFormer governor (4 years)
421942Ted CruzRepublicanTexasTexas 2nd in population (2010)Chair: Commerce
431943Elizabeth WarrenDemocraticMassachusettsMassachusetts 14th in population (2010)Vice Chair: Democratic Caucus Ranking Member: Banking
441944Deb FischerRepublicanNebraskaNebraska 38th in population (2010)
451948Ed MarkeyDemocraticMassachusettsJuly 16, 2013Ranking Member: Small Business
461949Cory BookerNew JerseyOctober 31, 2013Chair: Democratic Strategic Communications Committee
471951Shelley Moore CapitoRepublicanWest VirginiaJanuary 3, 2015Former House member (14 years)Chair: Republican Policy Committee Chair: Environment
481952Gary PetersDemocraticMichiganFormer House member (6 years); Michigan 8th in population (2010)Ranking Member: Homeland Security
491953Bill CassidyRepublicanLouisianaFormer House member (6 years); Louisiana 25th in population (2010)Chair: HELP
501955James LankfordOklahomaFormer House member (4 years)Vice Chair: Republican Conference Chair: Ethics
511956Tom CottonArkansasFormer House member (2 years); Arkansas 32nd in population (2010)Chair: Republican Conference Chair: Intelligence
521957Steve DainesMontanaFormer House member (2 years); Montana 44th in population (2010)
531958Mike RoundsSouth DakotaFormer governor
541960Thom TillisNorth CarolinaNorth Carolina 10th in population (2010)
551961Joni ErnstIowaIowa 30th in population (2010)Chair: Small Business
561963Dan SullivanAlaskaAlaska 47th in population (2010)
571964Chris Van HollenDemocraticMarylandJanuary 3, 2017Former House member (14 years)
581965Todd YoungRepublicanIndianaFormer House member (6 years)
591966Tammy DuckworthDemocraticIllinoisFormer House member (4 years)
601967Maggie HassanNew HampshireFormer governor
611969John KennedyRepublicanLouisianaLouisiana 25th in population (2010)
621970Catherine Cortez MastoDemocraticNevadaNevada 35th in population (2010)Vice Chair: Democratic Outreach Committee
631972Tina SmithMinnesotaJanuary 3, 2018
641974Cindy Hyde-SmithRepublicanMississippiApril 2, 2018
651975Marsha BlackburnTennesseeJanuary 3, 2019Former House member (16 years)
661977Kevin CramerNorth DakotaFormer House member (6 years)
671979Jacky RosenDemocraticNevadaFormer House member (2 years)
681982Josh HawleyRepublicanMissouri
691983Rick ScottFloridaJanuary 8, 2019Chair: Republican Steering Committee Chair: Aging
701985Mark KellyDemocraticArizonaDecember 2, 2020
711986Ben Ray LujánNew MexicoJanuary 3, 2021Former House member (12 years)
721987Cynthia LummisRepublicanWyomingFormer House member (8 years)
731988Roger MarshallKansasFormer House member (4 years)
741989John HickenlooperDemocraticColoradoFormer governor
751990Bill HagertyRepublicanTennesseeTennessee 17th in population (2010)
761991Tommy TubervilleAlabamaAlabama 23rd in population (2010)
771992Alex PadillaDemocraticCaliforniaJanuary 18, 2021Ranking Member: Rules
781993Jon OssoffGeorgiaJanuary 20, 2021'O' 15th letter of the alphabet
791994Raphael Warnock'W' 23rd letter of the alphabet
801995Peter WelchVermontJanuary 3, 2023Former House member (16 years)
811997Ted BuddRepublicanNorth CarolinaFormer House member (6 years)
821998John FettermanDemocraticPennsylvaniaPennsylvania 5th in population (2020)
832000Eric SchmittRepublicanMissouriMissouri 19th in population (2020)
842001Katie BrittAlabamaAlabama 24th in population (2020)
852002Pete RickettsNebraskaJanuary 12, 2023
862005Adam SchiffDemocraticCaliforniaDecember 8, 2024Former House member (24 years)
872006Andy KimNew JerseyFormer House member (6 years)
882007Ruben GallegoArizonaJanuary 3, 2025Former House member (10 years)
892008Jim BanksRepublicanIndianaFormer House member (8 years); Indiana 17th in population (2020)
902009Lisa Blunt RochesterDemocraticDelawareFormer House member (8 years); Delaware 46th in population (2020)
912010John CurtisRepublicanUtahFormer House member (7 years)
922011Elissa SlotkinDemocraticMichiganFormer House member (6 years)
932012Dave McCormickRepublicanPennsylvaniaPennsylvania 5th in population (2020)
942013Bernie MorenoOhioOhio 7th in population (2020)
952014Angela AlsobrooksDemocraticMarylandMaryland 18th in population (2020)
962015Tim SheehyRepublicanMontanaMontana 44th in population (2020)
972016Jim JusticeWest VirginiaJanuary 14, 2025
982017Jon HustedOhioJanuary 18, 2025
992018Ashley MoodyFloridaJanuary 21, 2025
1002019Alan S. ArmstrongOklahomaMarch 24, 2026
RankHistorical rankSenatorPartyStateSeniority dateOther factorsCommittee and leadership positions

See also

Notes