Cloture is the Senate's mechanism for ending debate on a matter it is considering. The Congressional Research Service puts its role precisely: cloture "is the only procedure by which the Senate can vote to set an end to a debate without also rejecting the bill, amendment, conference report, motion, or other matter it has been debating." It lives in paragraph 2 of Senate Rule XXII.

What it takes is not one number. CRS states the thresholds together: "The majority required to invoke cloture for most business is three-fifths of the Senators duly chosen and sworn, or 60 votes if there are no vacancies in the Senate's membership. However, invoking cloture on a measure or motion to amend the Senate's standing rules requires the votes of two-thirds of the Senators present and voting, or 67 votes if all 100 Senators vote. Additionally, under precedents established on November 21, 2013, and April 6, 2017, invoking cloture on presidential nominations requires a vote of a majority of Senators present and voting, or 51 votes if all 100 Senators vote."

The first of those is what people mean by the Senate's "60-vote rule." Note what it is a threshold for: ending debate, not passing the bill. "The votes of only a majority of Senators present and voting are needed to pass a bill on the floor" — passage is its own vote. The Senate's own page on filibusters and cloture describes the 1975 change that set it: "In 1975 the Senate reduced the number of votes required for cloture from two-thirds of senators voting to three-fifths of all senators duly chosen and sworn, or 60 of the 100-member Senate."

The Mechanics of a Cloture Vote

A cloture motion must be "signed by sixteen Senators." CRS describes how it reaches the floor: "To present a cloture motion, a Senator may interrupt another Senator who is speaking. When the motion is presented, the clerk reads it."

It does not ripen immediately. CRS: the motion "lies over until the second calendar day on which the Senate is in session. For example, if the motion is filed on Monday, it lies over until Wednesday, assuming the Senate is in session daily. If the motion is filed on Friday, it lies over until Tuesday unless the Senate was in session on Saturday or Sunday." Rule XXII fixes the hour: the presiding officer lays the motion before the Senate "one hour after the Senate meets on the following calendar day but one." In practice that timing is negotiable, and CRS notes it: "The time for the cloture vote may be changed by unanimous consent, and the required quorum call is routinely waived."

The threshold for most business is measured against the Senate's full membership, not its attendance: three-fifths of senators "duly chosen and sworn," which is "60 votes if there are no vacancies in the Senate's membership." CRS elsewhere states the arithmetic more exactly — cloture is invoked by "a vote of three-fifths of all Senators (60 votes if there is no more than one vacancy)." Enough empty seats lower the number required; a single empty seat does not, because three-fifths of 99 still rounds up to 60.

Invoking cloture does not end consideration. It caps it. Rule XXII allows "no more than thirty hours of consideration of the measure, motion, or other matter on which cloture has been invoked," after which "the Senate shall proceed, without any further debate on any question, to vote on the final disposition thereof." The cap moves in one direction: "The thirty hours may be increased by the adoption of a motion, decided without debate, by a three-fifths affirmative vote of the Senators duly chosen and sworn," and "only one motion to extend time, specified above, may be made in any one calendar day."

A defeated cloture motion settles nothing on its own. CRS: "there is no limit on the number of times that the Senate can vote on motions to invoke cloture on a bill, amendment, or other matter it is considering," and "Should a cloture motion be defeated, the majority leader may enter a motion to reconsider the cloture vote. This allows the majority leader to call up the motion at a subsequent time when he feels he has the votes and thereby obtain an immediate second vote on cloture."

Cloture Changes What Amendments Are Possible

Cloture is not only a clock. It closes off amendments, which gives a senator who supports a bill a structural reason to vote against ending debate on it.

Amendments have to be pre-filed, unless every senator agrees otherwise. Rule XXII: "Except by unanimous consent, no amendment shall be proposed after the vote to bring the debate to a close, unless it had been submitted in writing to the Journal Clerk by 1 o'clock p.m. on the day following the filing of the cloture motion if an amendment in the first degree, and unless it had been so submitted at least one hour prior to the beginning of the cloture vote if an amendment in the second degree." The rule also provides that "No dilatory motion, or dilatory amendment, or amendment not germane shall be in order."

That germaneness requirement has teeth, and CRS spells out the trade-off: "if the Senate invokes cloture on a bill, the presiding officer immediately rules on whether any pending amendment is germane. If the amendment is not germane, it falls and is ineligible for further consideration. If the Senators who wish to expedite passage of a bill also support a pending non-germane amendment to the bill, they cannot invoke cloture on the bill without also killing the amendment they favor."

There is a workaround, and it explains why the same bill can draw two cloture votes: "The alternative is to ask the Senate to invoke cloture on the amendment, not on the bill. Doing so protects the amendment from becoming subject to the germaneness requirement. After the Senate agrees to the amendment, however, it may be necessary for the Senate to invoke cloture a second time" on the bill as amended.

Cloture on Nominations

The nominations threshold was not set by amending Rule XXII. Amending the standing rules is protected by the rule itself, which requires "two-thirds of the Senators present and voting" to invoke cloture on such a measure. What happened instead, in the Senate's own words, is that "The Senate adopted new precedents in the 2010s to allow a simple majority to end debate on nominations."

CRS dates and describes both proceedings. On November 21, 2013 "the Senate reinterpreted the cloture rule to lower the threshold for invoking cloture for all nominations except to the Supreme Court." On April 6, 2017 the Senate "reinterpreted Rule XXII to allow a majority of Senators voting, a quorum being present, to invoke cloture on nominations to the U.S. Supreme Court." In each case a majority overturned a ruling of the chair rather than changing the rule's text: "Proceedings of this kind have been called 'the nuclear option' because they required actions arguably at variance with established principles underlying Senate procedure."

The threshold moved; the step did not disappear. "Importantly, neither the 2013 nor the 2017 precedent removed the potential need to invoke cloture on a nomination to reach a vote. The process for invoking cloture on a nomination remains the same." The post-cloture cap still applies — CRS describes the Senate reaching a vote on the nomination after "no more than 30 additional hours of consideration" — and confirmation is still "subject to a simple majority vote" of its own after debate ends.

Legislation was not touched. The Senate's account is that "filibusters remain a part of Senate practice, although only on legislation." Where a bill escapes the cloture step, it is a statute rather than a precedent that does it, by capping debate directly: 2 U.S.C. 641(e)(2) limits Senate debate on a reconciliation bill to "not more than 20 hours"; 5 U.S.C. 802(d)(2) provides that "In the Senate, debate on the joint resolution" of Congressional Review Act disapproval "shall be limited to not more than 10 hours"; and 19 U.S.C. 2191(g)(2) limits "Debate in the Senate on an implementing bill or approval resolution" to "not more than 20 hours." Those paths are set out in the filibuster explainer.

How Often Cloture Is Used

The Senate publishes a table, "Senate Action on Cloture Motions," running from the 65th Congress to the present. Its columns are "Congress Years Motions Filed Votes on Cloture Cloture Invoked."

The table opens with the 65th Congress, the one that adopted the rule: "65 1917-1918 2 0 0" — two motions filed, cloture invoked none. Use stayed low for decades. Through the 1960s the counts per two-year Congress were 4, 4, 7, 6 and 7 — "87 1961-1962 4 4 1", "88 1963-1964 4 3 1", "89 1965-1966 7 7 1", "90 1967-1968 6 6 1", "91 1969-1970 7 6 0".

The rise begins in the 1970s, not the 2010s. The five Congresses of that decade record "92 1971-1972 24 20 4", "93 1973-1974 44 31 9", "94 1975-1976 39 27 17", "95 1977-1978 23 13 3" and "96 1979-1980 30 21 10" — the 93rd alone filed more than the 1960s combined.

The most motions filed in any Congress in the table is the 117th's: "117 2021-2022 336 289 270." Which column you read matters, though — the 116th filed fewer but voted more often, "116 2019-2020 328 298 270," and the two tie on cloture invoked. The 118th recorded "118 2023-2024 266 241 227." The current Congress stood at "119 2025-2026 286 284 240" when this page's copy of the table was fetched, on the date recorded with that stored copy, August 31, 2026 — and the 119th Congress is not finished. Across every Congress the table's own footer totals "3,174 2,613 1,852."

What the growth means is easy to overstate. CRS attributes it to floor management rather than to a filibuster for every filing: "In recent times, by contrast, Senate leadership has increasingly made use of cloture as a normal tool for managing the flow of business on the floor, even when no evident filibuster has yet occurred." One common practice is procedural rather than adversarial: "it has become common practice for the majority leader to make a motion to proceed to consider a measure, immediately file cloture on that motion, and then withdraw the motion to proceed. This allows the Senate to conduct other floor business while the cloture petition is 'running' in the background."

And CRS cautions against reading the table as a filibuster count at all: "It would be erroneous to assume the presence or absence of cloture attempts is a reliable guide to the presence or absence of filibusters."

Key Sources

Drafted from primary source documents by LegislationPatch's automated research pipeline, then reviewed, verified, and edited by , Editor. Every figure and citation is checked against the official text before publication. See our editorial standards and AI disclosure.