What Vote Is Required to Override a Presidential Veto?

The vote required to override a presidential veto is two-thirds of the members present and voting in both the House of Representatives and the Senate. Both chambers must clear that threshold independently. If either falls short, the veto stands and the bill does not become law.

The Two-Thirds Rule in Practice

The Constitution says that after the President returns a bill with objections, “two thirds of that House shall agree to pass the Bill” for it to move forward. The Supreme Court read that phrase in Missouri Pacific Railway v. Kansas (1919) to mean two-thirds of a quorum, not two-thirds of the full membership.¹

A quorum is a simple majority of each chamber’s membership: 218 in the 435-member House, 51 in the 100-member Senate.² So the actual number of “yea” votes needed depends on how many members show up:

With full House attendance (435), it takes 290 votes to override.
At a bare House quorum (218), 146 would technically suffice.
With full Senate attendance (100), it takes 67 votes.
At a bare Senate quorum (51), 34 would technically suffice.

On a matter as visible as a veto override, attendance is usually near full, so the practical targets are 290 in the House and 67 in the Senate. Every override vote is a recorded roll call, with each member’s “yea” or “nay” entered in the Journal by name.¹

Both Chambers Have to Clear the Bar

The process runs in sequence. The chamber that originated the bill votes first. If it fails to reach two-thirds, the override is over and the second chamber never votes. If the originating chamber succeeds, the bill and the President’s objections go to the other chamber, which must independently reach the same two-thirds threshold. Success in one chamber alone accomplishes nothing.

Which Vetoes Can Be Overridden

Only regular vetoes are subject to override. When the President formally returns a bill to Congress with written objections during a session, Congress can reconsider it under the two-thirds rule.¹

A pocket veto is different. If Congress adjourns before the ten-day window for the President to act runs out, and the President has not signed the bill, it simply dies. There is no chamber in session to receive objections and no vote to hold, so a pocket veto cannot be overridden.¹

Two other limits are worth flagging. The veto power reaches bills and joint resolutions, but not proposed constitutional amendments, which go straight to the states after clearing both chambers by two-thirds. And the President cannot veto parts of a bill while signing the rest; the Supreme Court struck down the federal line-item veto in Clinton v. City of New York (1998).³

Timing After a Veto

There is no constitutional deadline for an override attempt. Congress can hold the vote days, weeks, or months after receiving the veto message. The House has postponed override votes for as long as eight months, even carrying them into the next session of the same Congress.⁴

The outer limit is the life of the Congress itself. When a new Congress is sworn in, the vetoed bill expires along with all other unfinished business, and any override attempt would have to start over with new legislation.⁵ Congressional leaders also have no obligation to schedule a vote at all. If the votes clearly are not there, they can simply let the veto stand.

How Often Overrides Actually Succeed

Rarely. Since 1789, Presidents have issued 2,599 vetoes — 1,533 regular and 1,066 pocket. Congress has overridden 112, a success rate of about 4.3%.⁶ The reason is straightforward: a President almost always has enough allies in at least one chamber to hold a third of the vote and block the override, so success generally requires substantial bipartisan agreement against the President’s position.

A few benchmarks show the range. Franklin D. Roosevelt issued 635 vetoes across four terms; Congress overrode 9. Andrew Johnson holds the record for overrides against a single President, with 15 of his 29 vetoes reversed by a Reconstruction Congress that was openly at odds with him. The most recent successful override came in late 2020 and early 2021, when Congress passed the National Defense Authorization Act for Fiscal Year 2021 over President Trump’s veto, 322–87 in the House and 81–13 in the Senate.⁷ Every veto issued since then has been sustained.⁶

1
Cornell University Law School / Legal Information Institute. Article I, Section 7, Clause 2: The Veto Power
2
Legal Information Institute (LII). Quorums in Congress
3
Legal Information Institute (LII) / Cornell Law School. Line-Item Veto
4
U.S. Government Publishing Office. House Practice: A Guide to the Rules, Precedents and Procedures of the House – Chapter 57. Veto of Bills
5
National Archives. Congress at Work – The Presidential Veto and Congressional Veto Override Process
6
U.S. Senate. Vetoes, 1789 to Present
7
U.S. Senate. Vetoes by President Donald J. Trump