Rules Governing Senate Committee and Subcommittee Assignment Procedures

Rules Governing Senate Committee and Subcommittee Assignment Procedures

Rules Governing Senate Committee and Subcommittee Assignment Procedures

Updated August 14, 2025 (R46806)
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Contents

Introduction

Scope of the Report

Senate Rules and Practices Relating to Standing Committee Assignments

Size and Ratios of Committees

Limitations

Democratic Conference Rules

Limitations

Republican Conference Rules

Limitations

Senate Committee Chair Appointments

Democratic Conference Rules

Limitations

Republican Conference Rules

Limitations

Senate Subcommittee Assignments

Limitations

Senate Subcommittee Chair Appointments

Democratic Conference Rules

Limitations

Republican Conference Rules

Limitations

Tables

Table 1. Senate Committee Categories

Table 2. Subcommittee Assignment Process

Table B-1. Joint Committee on Taxation

Table B-2. Joint Committee on Printing

Table B-3. Joint Committee on the Library

Table B-4. Joint Economic Committee

Appendixes

Appendix A. Committee Rules Pertaining to Subcommittee Assignments

Appendix B. Composition of Joint Committees

Summary

Each Congress, the Senate appoints its members to committees. In order to make these assignments, each party conference typically holds an organizational meeting following an election and prior to the start of the next Congress. At these meetings, committee assignments are first proposed and approved at the party level. These assignments are then formally approved in the Senate through the adoption of simple resolutions submitted on behalf of each party's conference. By long-standing practice, resolutions appointing Senators to committees have been adopted by unanimous consent.

Senate rules and party conference rules categorize committee types in two ways. First, committees are deemed to be standing or non-standing. "Standing committees" are permanently established under Senate Rule XXV, whereas "non-standing" committees (e.g., special, select, or joint committees) are typically created by resolution or law and are often temporary in nature. Second, Senate Rule XXV categorizes committees into three groups that are more popularly referred to as "A," "B," or "C" committees. In general, Senators "shall" serve on two "A" committees, may serve on one "B" committee, and are not limited in serving on "C" committees. Both the Democratic and Republican Conferences also further distinguish certain "A" committees as "Super A" or exclusive committees, typically limiting Senators to serving on one such committee at a time. However, committee assignments that violate these rules are sometimes proposed by the parties and adopted by the Senate.

In addition to Senate rules, committee assignments are also shaped by party conference rules. Within the Republican Conference, committee assignments are first recommended by either a Committee on Committees or the Republican Leader. These proposed assignments are then subject to approval by majority vote of the full Republican Conference. Once Republican committee rosters have been approved, Republican committee members elect their own chairs or ranking minority members, which must also be approved by majority vote of the conference.

Within the Democratic Conference, a Steering and Outreach Committee led by the Democratic Leader makes recommendations on all committee assignments, including who will be chair and who will fill any subsequent vacancies. Candidates nominated by Steering and Outreach must then be approved by a majority vote of the full Democratic Conference.

A number of further limitations apply to a Senator serving as a committee chair or ranking minority member. The rules of the Senate limit a Senator to serving as chair for no more than one committee at a time and for no more than one subcommittee per committee to which he or she is assigned. Republican Conference rules do not allow Republican chairs of "A" committees to chair any subcommittees. Republican chairs of "B" committees may chair only one subcommittee, and a Republican chair or vice chair of the Committee on Ethics may chair two subcommittees. All other Republican Senators are limited to serving as chair or ranking member for not more than two subcommittees. In addition, the Republican Conference limits service as the chair or ranking minority member of a committee to three terms (or six years).

Democratic Conference rules generally limit its members to holding no more than two "gavels" at a time. A Democratic Senator can serve as chair/ranking member of one full committee and one subcommittee, or as chair/ranking member of two subcommittees. A third gavel is permitted if all other Democratic Senators have had the opportunity to hold two gavels. In addition, the Democratic Leader may not serve as chair or ranking minority member of any committee or subcommittee. The Democratic Whip may serve as chair/ranking member for one committee or subcommittee.

While the Senate formally appoints Senators to committees, committees are responsible for appointing their members to subcommittees. Senate rules establish some limitations on subcommittee service but are silent on how these appointments should be made. However, a number of committees have adopted rules that provide for subcommittee assignments to be made either by the committee's chair or through a bidding process operating in order of seniority. In addition, Republican Conference rules direct that subcommittee leadership for Republican Senators shall be determined by seniority on either the committee or the subcommittee.

Introduction

The Senate appoints committees at the start of each two-year Congress in order to delegate its workload and develop expertise among its members. By serving on committees, Senators have the opportunity to work with colleagues on specific policy areas, develop and consider legislation, and conduct oversight of matters of national interest. Senators are formally assigned to committees by the Senate, but these assignment decisions are primarily driven by the parties themselves.

Following an election and prior to the start of a new Congress, both the Republican and Democratic Conferences typically hold organizational meetings to adopt committee assignments along with other party agenda items. The Republican Conference appoints a Committee on Committees to determine a portion of assignments for Republican Senators, while the party floor leader is responsible for the rest. The Democratic Conference appoints a Steering Committee to recommend committee assignments for its members. After the parties have approved committee assignments, simple resolutions reflecting these decisions are submitted and adopted in the Senate.

This report provides an examination of Senate and party rules governing the committee assignment process for both standing and non-standing committees as well as their subcommittees. The term standing committees generally refers to committees permanently established under Senate Rule XXV that have legislative and oversight jurisdiction over a number of stated subject areas. Non-standing committees (e.g., select, special, or joint committees) are created by resolution or law, typically to investigate certain issues or events, and may or may not have legislative jurisdiction.¹

Scope of the Report

A number of limitations regarding the public availability of information affect the discussion presented here. Discussion of both Republican and Democratic Conference rules in this report is limited to what the parties have made available to the public.² While Republican Conference rules have remained largely unchanged since at least the 114th Congress, readers should ultimately consult with conference staff for an authoritative application of current party rules. Democratic Conference rules were made publicly available for the first time during the 118th Congress, and any historical changes prior to that point are not readily available outside of inconsistent news and academic reporting.

In addition to the inconsistent availability of party conference rules, both parties also observe long-standing, but unwritten, practices that further shape the committee assignment process. These practices, exercised in party meetings not open to the public, can neither authoritatively nor comprehensively be accounted for in this report. Despite the limitations discussed here, this report offers an examination of the rights of all Senators under Senate rules and both parties' conference rules, either of which might be relied upon in complicated or contentious situations.

Senate Rules and Practices Relating to Standing Committee Assignments

At the start of every two-year Congress, and throughout as vacancies may arise, Senators are formally appointed to serve on committees through the adoption of simple resolutions.³ Typically, the floor leaders submit resolutions on behalf of each party to elect Senators as members and chairs (or ranking minority members) with names arranged in order of seniority for each committee to which appointments are being made.⁴ While technically debatable and amendable, these resolutions have typically been agreed to by unanimous consent, reflecting the long-standing practice of each party determining its own membership to committees. Senate Rule XXIV also provides that a Senator can demand a separate vote on any individual appointment,⁵ and one-fifth of Senators present (assuming a quorum) can demand that votes on an appointment resolution be taken by ballot—though neither rule has been exercised in decades.⁶

Once Senators have been assigned to committees, they continue to serve from Congress to Congress until they are replaced (when new assignments are adopted by the Senate).⁷ As previously discussed, it is the usual practice that committee assignments are adopted shortly after the start of a new Congress. However, if there is a delay in making new assignments for any reason, committees remain constituted and can continue to conduct business as they may deem necessary.⁸

Size and Ratios of Committees

Although the size of committees is provided for in Senate Rule XXV, in practice the Senate does not adhere to these restrictions. Instead, the size and ratio of majority to minority party members on each committee are negotiated by party leaders following an election and prior to the start of a new Congress.⁹ Committee ratios typically reflect the makeup of majority party to minority party Senators in the chamber.¹⁰ The size and ratio of Senators on each standing committee are reflected in the contents of the appointing resolutions adopted by the Senate.¹¹

Certain non-standing committees are subject to additional composition requirements set forth in resolutions that establish them. An equal number of Republicans and Democrats are always appointed to the Select Committee on Ethics, though the committee's total size varies from Congress to Congress. The Select Committee on Intelligence is partially composed of an equal number of Democratic and Republican Senators serving on other committees, as follows:

One Democrat and one Republican from the Committee on Appropriations,

One Democrat and one Republican from the Committee on Armed Services,

One Democrat and one Republican from the Committee on Foreign Relations, and

One Democrat and one Republican from the Committee on the Judiciary.

In addition, the committee may also have up to seven additional members appointed from the Senate at large.¹² Joint committees also have particular compositional requirements that can be found in Appendix B.

Limitations

Senate Rule XXV, paragraph 4, limits the number of committees that Senators may serve on at a time. These committees are more commonly referred to as "A," "B," and "C" committees, with each category representing a different aspect of the rule. Senators "shall" serve on two "A" committees, may serve on one "B" committee, and may serve on one or more "C" committees. Under the rule, appointment to the Joint Economic Committee does not count as a Senator's one "B" committee assignment, meaning that Senators on that committee may also be assigned to serve on a second "B" committee.¹³ In addition, Senators serving on the Committee on Rules and Administration may not serve on the Joint Committee on Taxation or Joint Economic Committee.¹⁴

Both the Republican and Democratic parties also consider a subset of "A" committees to be exclusive or "Super A" committees. Senators may generally serve on one exclusive or "Super A" committee, though either party conference could approve assignments for its members that would otherwise violate these party rules. Limitations under Senate and party rules are listed in Table 1.

Table 1. Senate Committee Categories

"A" Committees

"B" Committees

"C" Committees

Senators shall serve on two and no more

Senators may serve on only one

No limit on service

Agriculture, Nutrition, and Forestry

Budget

Ethics (Special)

Appropriations

Rules and Administration

Indian Affairs

Armed Services

Veterans' Affairs

Joint Committee on Taxation

Banking, Housing, and Urban Affairs

Small Business

Joint Committee on the Librarya

Commerce, Science, and Transportation

Aging (Special)

Joint Committee on Printinga

Energy and Natural Resources

Joint Economic Committeeb

Environment and Public Works

Finance

Foreign Relations

Homeland Security and Governmental Affairs

Judiciary

Health, Education, Labor, and Pensions

Intelligencec (Select)

Source: CRS examination of Senate Rule XXV, paragraph 4; Democratic and Republican Conference rules; and Senate Conference practices.

Notes: "A" committees appearing in italics are considered as "Super A" committees under Republican Conference rules. "A" committees appearing in bold are considered as exclusive committees under Democratic Conference rules. Both parties designate the Committees on Appropriations, Armed Services, and Finance as "Super A" committees. The Republican Conference also designates the Committee on Foreign Relations as a "Super A" committee. Senators are generally not assigned to more than one exclusive or "Super A" committee by their respective party conference.

a. The committee does not appear in Senate rules and is therefore treated as a "C" committee, which has no limitations for assignment purposes.

b. Service on the Joint Economic Committee does not count toward the one "B" committee limit, per Senate Rule XXV, paragraph 4(d). In other words, Senators may potentially serve on a second "B" committee when assigned to the Joint Economic Committee.

c. The Select Committee on Intelligence is considered as an "A" committee pursuant to Section 301(b) of S.Res. 445, 108th Congress (2003-2004).

Democratic Conference Rules

The Democratic Conference uses a Steering and Outreach Committee to make recommendations for all assignments to standing, special, and select committees, including any vacancies thereon when they arise.¹⁵ When making recommendations to fill vacancies, conference rules specify that Steering and Outreach makes decisions independent of committee leadership. Ultimately, all recommendations made by Steering and Outreach are subject to approval by the full conference.

In considering committee assignments, the Steering Committee is directed by Conference Rule X, clause 3, to make recommendations "giving due consideration" to seniority of service in the Senate, the preferences of Democratic Senators, and uninterrupted service on the committee(s) in question.¹⁶ The Steering Committee is also directed to assign freshman members of the conference to at least one "A" committee (including Intelligence) of their choice "to the extent possible."

The Democratic Conference also prioritizes the reappointment to committees (1) of Senators who lose an assignment because of changes in the ratio between the majority and minority parties (sometimes referred to as "bumping rights") or (2) of Senators who voluntarily relinquish an assignment at the request of the Conference Chair. In either case, conference rules state that those Senators will receive priority in filling vacancies on committees where their assignments were lost.

Limitations

The Democratic Conference sets a number of limitations on how its members are assigned to committees. Certain committees are designated as exclusive (sometimes informally referred to as "Super A" committees), and Democratic Senators may not serve on more than one until all members of the conference are assigned to at least one. Per Conference Rule X, clause 9, the following committees are deemed exclusive:

Appropriations,

Armed Services, and

Finance.

This limitation does not apply to Democratic Senators who were serving on more than one exclusive committee prior to the rule's formal adoption by the conference in 2017. In addition, the Steering and Outreach Committee may waive this rule for other members of the conference as considered necessary.

Democratic Senators from the same state may not be recommended to serve together on the same committee by the Steering and Outreach committee.¹⁷ This restriction can also be waived by Steering and Outreach as desired.

Republican Conference Rules

Within the Republican Conference, a Committee on Committees is responsible for recommending assignments to "A" committees and to the Committee on Rules and Administration (see Table 1).¹⁸ The party leader recommends all other Republican committee assignments. Recommendations made by the Committee on Committees and the party leader are subject to majority approval vote by the full conference.

At the start of a Congress, the Committee on Committees sends a letter to all Republican Senators asking them to submit their preferences for assignments. Senators are directed to rank their top three preferred "A" committee assignments, with the understanding they may not be assigned to their third requested assignments.¹⁹ According to conference precedents, the Committee on Committees then uses the following guidelines, in order, when composing its recommended assignments:

1. seniority of service on committees,

2. seniority of service in the Senate,

3. attention to geographical distribution and balance,

4. no Senator to be assigned to serve on Finance and Appropriations at the same time,

5. no two Republican Senators from the same state to be on the same committee, and

6. ties determined by draw.

Once assignments for returning Senators have been made, incoming freshmen are assigned to remaining vacancies. Freshmen Senators are each guaranteed an initial assignment before any other freshman receives a second assignment. Seniority among the freshman class, for purposes of selecting a committee assignment, is first determined by prior service in the Senate, prior service in the House, and then prior service as a state governor. For all other newly elected Senators, order of committee selection is determined by draw.²⁰ The party leader then proposes assignments to any remaining vacancies on "A" committees.

Republican Senators may keep one "B" committee assignment on which they served in the previous Congress. As with remaining "A" vacancies, the party leader proposes remaining "B" and "C" assignments. If a Senator loses an assignment because of changes in the ratio between majority and minority parties on a committee, the Republican Conference gives the Senator priority for the next available vacancy on the committee on which the seat was lost (sometimes referred to as "bumping rights"). All committee assignments are then subject to the approval of the full conference, votes on which may be taken by secret written ballot if contested.

Limitations

The Republican Conference has adopted a number of rules and precedents that further limit Senators' service on committees beyond those found in Senate rules. As identified earlier, in Table 1, the Republican Conference designates certain "A" committees as exclusive assignments (which are commonly referred to as "Super A" committees). Conference Rule V, Section G, states that Republican Senators may serve on not more than one of the following "Super A" committees at a time:

Appropriations,

Armed Services,

Finance, and

Foreign Relations.

Republican Conference precedents also reflect limitations taken into consideration by the Committee on Committees when recommending two "A" committee assignments for each Republican Senator. First, these precedents emphasize that the committee should not assign one Senator to both the Finance and Appropriations Committees at the same time, reinforcing the intended exclusivity of "Super A" committees. The committee has also established that Republican Senators from the same state should not be assigned to the same committee.²¹ However, Senators may receive assignments that might otherwise violate these rules if approved by a majority of the full conference (and subsequent adoption by the Senate of an appointing resolution).

Senate Committee Chair Appointments

Senate rules place a number of limits on committee chairs serving concurrently on other committees and subcommittees. In general, Senators may not serve as chair for more than one committee.²² The one exception to that rule provides that a committee chair may also chair a joint committee if the two committees in question share related jurisdiction.²³

Democratic Conference Rules

Democratic committee chairs (or ranking minority members) are primarily nominated by the Steering and Outreach Committee, subject to approval by the full Democratic Conference. Other nominations for these positions may be considered only if the candidate nominated by Steering and Outreach fails to be approved by a majority vote of the conference. When a committee leadership position has multiple candidates, the conference votes by secret ballot. If no candidate receives majority support, the candidate with the least votes is eliminated, and the conference proceeds to the next ballot. This process continues until a single candidate wins majority support (or fails to do so and new recommendations can be made). When there is only one candidate for a committee leadership post, they are still subject to vote by the conference and must receive majority support to be elected.²⁴

Once candidates for committee leadership have been approved by the Democratic Conference, their names are submitted to the Senate in the form of a simple resolution for consideration and adoption by the chamber.

Limitations

Democratic Conference rules are stricter than Senate rules on how many committee leadership positions an individual Senator can hold simultaneously. Democratic Senators may generally hold no more than a total of two committee leadership posts at the same time (either as chair/ranking of one committee and one subcommittee, or as chair/ranking on two subcommittees). Within the conference, this limitation is sometimes referred to as the "two gavel rule." Holding a third gavel is permitted, if necessary, only after all members of the conference have been given the opportunity to obtain two gavels.

Further limitations on holding committee leadership posts apply to the Democratic Leader and Democratic Whip. The Democratic Leader is prohibited from serving as a chair or ranking minority member on any standing committee (or subcommittee). The Democratic Whip may serve only as chair or ranking minority member for either one standing committee or one subcommittee.

Republican Conference Rules

In the Republican Conference, committee chairs (and ranking minority members) are subject to a multistep approval process, first by Republican committee members, then the full conference, and finally by formal approval of the committee membership appointment resolution (which implicitly or explicitly identifies the chair and ranking minority member) on the Senate floor. Because chairs are nominated from within a committee's membership, the party's committee assignments must first be approved by the conference. Republican committee members then nominate a candidate, by majority vote, to serve as chair (or ranking minority member, as applicable). Conference Rule V states that Senators are not bound by committee seniority when selecting a chair. If there are multiple candidates for the position, the vote is by secret written ballot, pursuant to Conference Rule I.

Once a chair has been nominated by Republican committee members, he or she must then be approved by a majority of the full Republican Conference, which votes by secret written ballot. If a candidate does not receive majority support from the conference, the committee is directed to submit a new nominee for consideration.

Limitations

Republican committee chairs are subject to a number of limitations under Republican Conference rules in addition to those found in Senate rules. Service as a committee chair is limited to not more than six cumulative years. After six years total as chair, a Senator may not continue to serve as the ranking minority member of that committee when the party is in the minority in the Senate.²⁵ Service as a ranking minority member is also limited to not more than six cumulative years of service. However, a Senator serving as a ranking minority member may then also serve an additional six years as committee chair. Under Republican Conference precedents, service as chair or ranking member for a term of one year or less does not count toward the six-year limit on either position.²⁶

While Senate rules generally limit Senators to serving as chair of only one committee at a time, Republican Conference rules extend that limit to ranking minority members as well. In other words, Republican Senators may serve as chair or ranking minority member of one committee. However, there are two exceptions to this rule that apply in relation to joint committees: First, the chair of the Committee on Finance may concurrently serve as the chair of the Joint Committee on Taxation, and second, the chair of the Committee on Rules may also serve as chair of the Joint Committee on Printing or the Joint Committee on the Library.²⁷

Republican Conference rules prohibit the party floor leader and assistant party floor leader from serving as chair or ranking member on any standing committees, the Joint Committee on Taxation, or the Joint Economic Committee.²⁸ Under these limitations, they may still serve as chair or ranking minority member of non-standing committees or as ranking minority member on the Joint Committee on Printing or the Joint Committee on the Library.

Senate Subcommittee Assignments

Senate rules do not provide appointment procedures for subcommittees, and party conference rules address procedures only related to how subcommittee chairs (or ranking minority members) are determined. Unlike committee assignments, which are approved by the Senate through formal action on the floor, subcommittee assignments are the responsibility of the committees themselves. Some committee rules address appointment to subcommittees, while others do not. For those committees that do have rules on the subject, they appear to either use a bidding process based on committee seniority or empower the committee's chair to directly make subcommittee assignments. Table 2, below, provides a summary overview of subcommittee assignment methods adopted in committee rules. The full text of those specific committee rules can be found in Appendix A.

Table 2. Subcommittee Assignment Process

As defined under rules adopted by Senate committees

Committee

Appointed by Chair

Bidding by Seniority

Othera

No Rule

Agriculture, Nutrition, and Forestry

Rule 7

Appropriations

X

Armed Services

X

Banking, Housing, and Urban Affairs

Rule 3

Budget

X

Commerce, Science, and Transportation

Rule 7

Energy and Natural Resources

Rule 8

Environment and Public Works

Rule 6

Finance

Rule 17

Foreign Relations

Rule 2

Health, Education, Labor, and Pensions

X

Homeland Security and Governmental Affairs

Rule 8

Intelligence

Rule 3b

Judiciary

Rule 7

Rules and Administration

X

Small Business and Entrepreneurship

c

Veterans' Affairs

X

Source: CRS analysis of Senate committee rules as published in the Congressional Record.

Notes: The full text of committee rules listed in this table can be found in Appendix A.

a. Committee rules referenced in this column include language that discusses some aspect of the composition of subcommittees but does not otherwise specify an appointment process to those bodies.

b. Committee Rule 3 specifically provides that the chair and vice chair of each subcommittee is selected by the chair and vice chair of the full committee, respectively. The rule is silent on the appointment of other committee members to serve on subcommittees.

c. The Committee on Small Business and Entrepreneurship's committee rules state that "the Committee shall not have standing subcommittees."

Limitations

Service on subcommittees is limited in a number of ways under Senate rules. In particular, Senators may not serve on more than three subcommittees of each "A" committee, with the exception of the Committee on Appropriations, to which this limit does not apply. Furthermore, Senators may not serve on more than two subcommittees of each "B" committee. No "C" committees currently have any subcommittees. A committee's chair and ranking minority member may serve on all of their committee's subcommittees in an ex officio capacity. The rules of the Senate and those adopted by the party conferences set additional limitations on serving as a subcommittee chair and are discussed in greater detail in the next section.

Senate Subcommittee Chair Appointments

Senate Rule XXV, paragraph 4(e), provides several limitations on service as a subcommittee chair or ranking minority member. A Senator may serve as chair of no more than one subcommittee on each committee of which he or she is a member. More specific limitations apply to chairs of "A" and "B" committees.

An "A" committee chair may serve as the chair of one "A" subcommittee in total and one "B" subcommittee per "B" committee assignment. Assuming a Senator is assigned to committees in compliance with Senate Rule XXV, paragraph 4(a)—that is, two "A" committees and one "B" committee—an "A" committee chair could hold a maximum of two subcommittee chairs: one "A" subcommittee and one "B" subcommittee.

A "B" committee chair may serve as a subcommittee chair for one subcommittee on each "A" committee to which he or she is assigned and on no "B" subcommittees. Again, assuming a Senator is assigned to committees in compliance with Senate rules, a "B" committee chair could also hold a maximum of two subcommittee chairs: two "A" subcommittees and zero "B" subcommittees.

Subcommittee Chair Limits on "A" and "B" Committees

An "A" committee chair may serve as chair of one "A" subcommittee and one "B" subcommittee.

A "B" committee chair may serve as chair of two "A" subcommittees and zero "B" subcommittees.

Any other Senator may chair one subcommittee on each committee on which he or she serves (up to three total under the rule—two "A" subcommittees and one "B" subcommittee).

These limitations assume that each Senator is assigned to only two "A" committees and one "B" committee, as described in Senate Rule XXV, paragraph 4(a). Senate rules place no limits on serving as a chair to "C" subcommittees, though no "C" committees currently have any subcommittees.

Both Republican and Democratic Conference rules place additional limitations stricter than Senate rules on allowing committee chairs to also simultaneously serve as subcommittee chairs.

Democratic Conference Rules

There are no explicit procedures delineated within Democratic Conference rules for how subcommittee leadership positions are appointed. Instead, the party's rules emphasize limitations on leadership obtaining subcommittee gavels until after all members of the conference have an opportunity to secure one. By long-standing practice, the Democratic Conference has determined subcommittee chairs (or ranking minority members) by seniority on the full committee.

Limitations

Democratic Conference Rule XI provides that every Democratic Senator shall serve as chair (or ranking minority member) of at least one subcommittee and of no more than two (or of one standing committee and one subcommittee). As mentioned in the committees' section, this concept in the Democratic Conference is sometimes referred to as the "two gavel rule." Democratic Senators can hold a third gavel on a committee or subcommittee, as needed, after all other members of the conference have had the opportunity to hold two.

Additional limitations apply to certain leadership positions within the Democratic Conference and for chairs (or ranking minority members) of "A" committees. Conference Rule XI prohibits the Democratic Leader from serving as chair/ranking for any standing committee or subcommittee. The Democratic Whip is permitted to serve as chair/ranking for only one standing committee or subcommittee. "A" committee chairs (or ranking minority members) cannot select a leadership spot on any subcommittee until all Democratic Senators have had the opportunity to choose one.

Republican Conference Rules

Within the Republican Conference, subcommittee chairs or ranking minority members are determined by their seniority on either the subcommittee or the full committee. Conference Rule V, Section J, allows Senators to seek waivers, in order of seniority, to serve as subcommittee chairs or ranking members that would otherwise be prohibited under the party's rules. However, such waivers may be granted only after Republican Senators not needing waivers have declined the position. Waivers must be approved by a majority of the full Republican Conference.

Limitations

Republican chairs and ranking minority members of full committees are subject to limitations in serving as subcommittee chairs or ranking minority members. "A" committee chairs/ranking members may not serve as chairs or ranking members of any subcommittee, with certain exceptions on the Appropriations committee.²⁹ (This applies to "Super A" chairs/ranking members as well.) A committee chair or ranking member on any other committee, except the Committee on Ethics, may serve as chair/ranking member for one subcommittee. The chair or vice chair of the Committee on Ethics may serve as chair/ranking member of not more than two subcommittees. All other Republican Senators are also limited to serving as chair or ranking member for not more than two subcommittees. The six-year term limit on Republican committee leadership positions does not appear to apply to subcommittee chairs or ranking members.³⁰

Appendix A. Committee Rules Pertaining to Subcommittee Assignments

The information in this appendix represents annotated Senate committee rules, as reprinted in the Congressional Record, that directly reference composition of subcommittees. Table 2 further categorizes these rules according to any subcommittee assignment process identified therein.

Committee on Agriculture, Nutrition, and Forestry

Committee Rule 7.1:

Assignments.—To assure the equitable assignment of members to subcommittees, no member of the committee will receive assignment to a second subcommittee until, in order of seniority, all members of the committee have chosen assignments to one subcommittee, and no member shall receive assignment to a third subcommittee until, in order of seniority, all members have chosen assignments to two subcommittees.

Committee on Banking, Housing, and Urban Affairs

Committee Rule 3:

[a] Authorization for. A Subcommittee of the Committee may be authorized only by the action of a majority of the Committee.

[b] Membership. No member may be a member of more than three Subcommittees and no member may chair more than one Subcommittee. No member will receive assignment to a second Subcommittee until, in order of seniority, all members of the Committee have chosen assignments to one Subcommittee, and no member shall receive assignment to a third Subcommittee until, in order of seniority, all members have chosen assignments to two Subcommittees.

Committee on Commerce, Science, and Transportation

Committee Rule VII:

2. CHANGE OF CHAIR.—Subcommittees shall be considered de novo whenever there is a change in the chairmanship, and seniority on the particular subcommittee shall not necessarily apply.

Committee on Energy and Natural Resources

Committee Rule 8:

(a) The number of Members assigned to each Subcommittee and the division between Majority and Minority Members shall be fixed by the Chairman in consultation with the Ranking Minority Member.

(b) Assignment of Members to Subcommittees shall, insofar as possible, reflect the preferences of the Members. No Member will receive assignment to a second Subcommittee until, in order of seniority, all Members of the Committee have chosen assignments to one Subcommittee, and no Member shall receive assignment to a third Subcommittee until, in order of seniority, all Members have chosen assignments to two Subcommittees.

Committee on Environment and Public Works

Committee Rule 6:

(a) Regularly Established Subcommittees: The committee has four subcommittees: Transportation and Infrastructure; Clean Air, Climate, and Nuclear Innovation and Safety; Chemical Safety, Waste Management, Environmental Justice, and Regulatory Oversight; and Fisheries, Water, and Wildlife.

(b) Membership: The Chair, after consulting with the Ranking Minority Member, shall select members of the subcommittees.

Committee on Finance

Committee Rule 17:

(a) The chairman, subject to the approval of the committee, shall appoint legislative subcommittees. The ranking minority member shall recommend to the chairman appointment of minority members to the subcommittees. All legislation shall be kept on the full committee calendar unless a majority of the members present and voting agree to refer specific legislation to an appropriate subcommittee.

Committee on Foreign Relations

Committee Rule 2:

(a) Creation.—Unless otherwise authorized by law or Senate resolution, subcommittees shall be created by majority vote of the committee and shall deal with such legislation and oversight of programs and policies as the committee directs. Legislative measures or other matters may be referred to a subcommittee for consideration in the discretion of the chairman or by vote of a majority of the committee. If the principal subject matter of a measure or matter to be referred falls within the jurisdiction of more than one subcommittee, the chairman or the committee may refer the matter to two or more subcommittees for joint consideration.

(b) Assignments.—Assignments of members to subcommittees shall be made in an equitable fashion. No member of the committee may receive assignment to a second subcommittee until, in order of seniority, all members of the committee have chosen assignments to one subcommittee, and no member shall receive assignments to a third subcommittee until, in order of seniority, all members have chosen assignments to two subcommittees. No member of the committee may serve on more than four subcommittees at any one time.

Committee on Homeland Security and Governmental Affairs

Committee Rule 8:

A. Regularly established Subcommittees. The Committee shall have three regularly established Subcommittees. The Subcommittees are as follows:

PERMANENT SUBCOMMITTEE ON INVESTIGATIONS

SUBCOMMITTEE ON DISASTER MANAGEMENT, DISTRICT OF COLUMBIA, AND CENSUS

SUBCOMMITTEE ON BORDER MANAGEMENT, FEDERAL WORKFORCE, AND REGULATORY AFFAIRS

B. Ad hoc Subcommittees. Following consultation with the Ranking Minority Member, the Chair shall, from time to time, establish such ad hoc Subcommittees as the Chair deems necessary to expedite Committee business.

C. Subcommittee membership. Following consultation with the Majority Members, and the Ranking Minority Member of the Committee, the Chair shall announce selections for membership on the Subcommittees referred to in paragraphs A and B, above.

Select Committee on Intelligence

Committee Rule 3:

Creation of subcommittees shall be by majority vote of the Committee. Subcommittees shall deal with such legislation and oversight of programs and policies as the Committee may direct. The subcommittees shall be governed by the Rules of the Committee and by such other rules they may adopt which are consistent with the Rules of the Committee. Each subcommittee created shall have a chairman and a vice chairman who are selected by the Chairman and Vice Chairman, respectively.

Committee on the Judiciary

Committee Rule VII:

2. Subcommittees shall be considered de novo whenever there is a change in the Subcommittee chairmanship and seniority on the particular Subcommittee shall not necessarily apply.

Committee on Small Business and Entrepreneurship

"Subcommittees" (no rule number):

The Committee shall not have standing subcommittees.

Appendix B. Composition of Joint Committees

Joint committees are established by law and are composed of an equal number of members from the House and the Senate. At present, there are four joint committees in operation. The full composition of these joint committees is listed, below.

Table B-1. Joint Committee on Taxation

26 U.S.C. §8002

Five Members from the Senate Committee on Finance

Five Members from the House Committee on Ways and Means

Three Majority Members and Two Minority Members

Three Majority Members and Two Minority Members

Table B-2. Joint Committee on Printing

44 U.S.C. §101

Five Members from the Senate Committee on Rules and Administration

Five Members from the House Committee on House Administration

Four Members and the Chair of the Committee

Four Members and the Chair of the Committee

Table B-3. Joint Committee on the Library

2 U.S.C. §132b

Five Members from the Senate Committee on Rules and Administration

Five Members from the House Committee on House Administration

Four Members and the Chair of the Committee

Four Members and the Chair of the Committee

Table B-4. Joint Economic Committee

15 U.S.C. §1024

10 Members of the Senate

10 Members of the House

Six Majority Members and Four Minority Members

Six Majority Members and Four Minority Members

Footnotes

1.

More discussion on the types of committees in the Senate (and House) can be found in CRS Report 98-241, Committee Types and Roles, by Valerie Heitshusen.

2.

Republican Conference rules for the 119th Congress (2025-2026) can be found at https://www.republican.senate.gov/wp-content/uploads/2025/05/119NewRulesTemp.pdf. Democratic Conference rules for the 119th Congress (2025-2026) are available at https://www.democrats.senate.gov/rules-for-the-democratic-conference.

3.

Practice varies from Congress to Congress, but not all committee assignments for a party's members are necessarily submitted in a single resolution. Committee assignments may be determined piecemeal, meaning multiple resolutions could be submitted and adopted in the Senate. Furthermore, as changes in membership to the Senate occur over the course of a Congress—whether the result of a retirement, special election, death, or other circumstance—additional resolutions appointing individual Senators to committees may be considered and adopted as well.

4.

For example, in the 117th Congress (2021-2022), S.Res. 28 appointed Senators from the majority party to committees, and S.Res. 32 appointed Senators from the minority party. Occasionally, as is the case with S.Res. 28, resolutions appointing majority party committee assignments will specify in the text which Senator is designated as chair (e.g., Ms. Smith [Chair]). However, as already mentioned, even in the absence of this designating text, committee assignment resolutions always list a committee's chair (for the majority party) or ranking member (for the minority party) first. All other Senators are listed in order of their seniority on the committee.

5.

According to Riddick's Senate Procedure, the Senate most recently considered a motion to divide the question on a resolution appointing committee members and chairs during the 92nd Congress (1971-1972); see U.S. Congress, Senate, Riddick's Senate Procedure, 101st Cong., 2nd sess., Doc. 101-28, p. 396, and Congressional Record, vol. 117 (January 28, 1971), pp. 866-868.

6.

The last time the Senate considered committee assignments by ballot was during the 83rd Congress (1953-1954). In that instance, neither party had proposed assignments for then-independent Senator Wayne Morse, who was not caucusing with Republicans or Democrats at the time. After some debate on how to proceed, the Senate agreed to a motion by voice vote establishing balloting procedures for assignments to the Committee on Armed Services. The motion directed Senators to submit signed ballots listing their preferred assignments to the committee as their names were called by roll. Ballots were distributed to all Senators containing assignments to the Committee on Armed Services proposed by the Republican and Democratic parties. Senators could then either accept the parties' proposed assignments or write in Senator Morse's name and strike another name off the ballot list. The ballot vote resulted in adoption of the parties' proposed assignments, and Senator Morse was not assigned to the Committee on Armed Services for the 83rd Congress. See U.S. Congress, Senate, Riddick's Senate Procedure, 101st Cong., 2nd sess., Doc. 101-28, p. 395, and Congressional Record, vol. 99 (January 13, 1953), pp. 327-352.

7.

Senate Rule XXV, paragraph 1, states that "standing committees shall be appointed at the commencement of each Congress, and shall continue and have the power to act until their successors are appointed, with leave to report by bill or otherwise on matters within their respective jurisdictions."

8.

For example, because of runoff elections that would determine the majority party in the Senate for the 117th Congress (2021-2022), committee assignments were not adopted until one month into the session. During the interim, Senate committees—reflecting membership assignments from the 116th Congress (2019-2020)—acted in several cases to consider and report nominations submitted by the new Biden Administration. For more information on the Senate at the outset of the 117th Congress and the chamber's eventual powersharing agreement, see CRS Report R46769, The Senate Powersharing Agreement of the 117th Congress (S.Res. 27), by Elizabeth Rybicki.

9.

See CRS Report RS20722, The First Day of a New Congress: A Guide to Proceedings on the Senate Floor, by Valerie Heitshusen.

10.

The Select Committee on Ethics is always composed of an equal number of Republican and Democratic members, pursuant to S.Res. 338 (88th Congress), regardless of the party ratios in the Senate.

11.

See CRS Report RL34752, Senate Committee Party Ratios: 98th-119th Congresses, by Sarah J. Eckman.

12.

Pursuant to the committee's establishing resolution, the President pro tempore is the one authorized to make appointments, as recommended by the floor leaders, to the eight Intelligence Committee seats composed of members from the Committees on Appropriations, Armed Services, Foreign Relations, and the Judiciary. In practice, the floor leaders name all members to the Select Committee on Intelligence for their respective parties in simple resolutions submitted to and approved by the Senate. U.S. Congress, Senate Committee on Rules and Administration, Senate Manual, 117th Cong., 2nd sess., 117-1 (Washington: GPO, 2023), Section 82, p. 126.

13.

Senate Rule XXV, paragraph 4(d).

14.

Senate Rule XXV, paragraph 4(f).

15.

Democratic Steering and Outreach Committee members are appointed by the Democratic Leader, in their role as Democratic Conference Chair, subject to confirmation by the full Conference.

16.

Democratic Conference Rule X, clause 4, clarifies that seniority is based on a Senator's continuous service. That is, if a Democratic Senator had prior Senate service, left Congress, and then was later reelected, their seniority would begin at the time of their reentry into the party conference.

17.

Democratic Conference Rule X, clause 5.

18.

The Republican Committee on Committees is appointed by the chair of the Republican Conference and then confirmed by the full membership of the conference itself. The conference chair is elected by the Republican Conference at the beginning of a new Congress along with other conference party leaders. In practice, however, the party floor leader (majority or minority leader) selects the conference chair (e.g., see Senator Mike Crapo's press release announcing his selection as conference chair for the 117th Congress at https://www.crapo.senate.gov/media/newsreleases/-crapo-chairs-committee-on-committees-announces-committee-assignments-for-117th-congress).

19.

According to a precedent adopted by the Republican Conference in 1992. See "Committee Selection Process," History, Rules and Precedents of the Senate Republican Conference, 117th Cong., p. 9, https://www.republican.senate.gov/wp-content/uploads/2022/09/4AD00AC45F860D42FAD37C556CB6A01F.-117th-congresss-rules-and-precedents.pdf (hereinafter Rules and Precedents of the Senate Republican Conference).

20.

Rules and Precedents of the Senate Republican Conference, Section H, p. 5.

21.

Rules and Precedents of the Senate Republican Conference, "Service re: Two Republican Senators from the Same State Serving on the Same Committee," p. 6, and "Precedents in Selection from Minutes of the Republican Conference," p. 8.

22.

Senate Rule XXV, paragraph 4(e)(1).

23.

For example, the chair of the Senate Committee on Finance could also concurrently serve as the chair of the Joint Committee on Taxation.

24.

Democratic Conference Rule V describes the balloting procedures detailed in this paragraph.

25.

Republican Conference Rule V, Section B(2), specifies that "time served as ranking member shall not be counted as time served as chairman." This means that, in the event of changes in party control of the Senate, a Senator could serve as chair and then ranking member for up to 12 cumulative years. For example, Senator John Doe could serve as committee chair for four years before the Republican Party then becomes the minority party in the Senate for the next six years. During those six years, Senator John Doe could serve as ranking minority member on the committee—none of which counts against his two remaining eligible years to be chair. After these six years as ranking member, the Republican Party could gain majority control of the Senate and Senator John Doe is eligible to serve two more years as committee chair before he is ineligible for further service as chair or ranking minority member.

26.

Rules and Precedents of the Senate Republican Conference, "Term Limits for Leadership and Committee Chairs," p. 9.

27.

Both of these exceptions adhere to and are a further interpretation of Senate Rule XXV, paragraph 4(e)(1), which limits Senators to serving as chair of not more than one committee except for concurrent service as chair to a joint committee in cases where both committees share directly related jurisdictional subject matter.

28.

Conference Rule V, Section A, specifically prohibits floor leaders from serving as chair or ranking member on joint committees for which the membership "is not determined by ranking position on a standing committee." The rule does not apply to the Joint Committee on Printing or the Joint Committee on the Library, as their membership is determined, in part, by ranking position on a standing committee. (Specifically, the chair of the Committee on Rules and Administration is statutorily required to be a member of both Joint Committees.)

29.

This rule does not apply to Senators who served on the Committee on Appropriations prior to the 113th Congress (2013-2014), who may still serve as chair or ranking member on that committee's subcommittees (Republican Conference Rule V, Section C(1)(B)).

30.

Term limits for service are limited to standing committee chairs and ranking members in Conference Rule V, Section B. Conference Rule I also states, "A Senator shall serve no more than three terms in any elected party leadership position other than Floor Leader or President Pro Tempore"; however, Republican subcommittee chairs and ranking members appear to be determined by seniority and not election (according to Conference Rule V, Section G, meaning those positions would not fall under the scope of that limitation).