How does a bill become a law? The short answer
In the United States, a bill is a proposal for a new law or a change to an existing one.3 To become a federal law, it has to pass both chambers of Congress, the House of Representatives and the Senate, in exactly the same words, and then get past the President: usually by being signed.61 It can also become law if the President neither signs nor returns it within 10 days (Sundays excepted) while Congress is in session, or if Congress overrides a veto with a two-thirds vote in both chambers.2
idea → committee → House vote → Senate vote → same text → President → law
It sounds simple, but it's a tough path. In the 2023–2024 Congress, members introduced 19,315 bills and resolutions, and only 274 were enacted as laws: about 1 in 70.9
How a bill becomes a law, step by step
Here is the path as a simple flowchart. We'll follow a made-up example, the National Park Birthday Act, which would give every national park a free-entry day on its birthday. (It isn't a real bill.)
- An idea. Ideas can come from anyone: members of Congress, citizens and groups who petition their representatives, or the President.31
- Introduction. Only a member of Congress can introduce a bill. In the House, the member drops it into the hopper, a wooden box at the side of the rostrum. No permission is needed.1 The bill gets a number: "H.R." for House bills, "S." for Senate bills.6
- Committee. The bill is sent to the committee that handles its subject. The committee can hold hearings with experts, then rewrite the bill in a "markup" session and vote on whether to send it on.1
- Floor vote. If the committee reports it, the bill can go to the whole chamber, which debates it, may amend it, and votes. A simple majority passes it.4
- The other chamber. The bill goes through a committee, debate and a vote again in the other chamber.34
- Matching versions. Both chambers must pass identical text. Differences are settled by trading amendments or in a conference committee.1
- The President. The final "enrolled" bill goes to the President, who can sign it, veto it, or do nothing.12
- Override (if vetoed). Two-thirds of both chambers can override a veto.2 Once it's law, it gets a public law number and is published.8
Step 1–2: where do bills come from?
Anyone can have the idea for a law. Citizens and groups have a constitutional right to petition Congress, and the President suggests laws too, for example in the State of the Union message.1 But only a member of Congress can actually introduce a bill. The member who introduces it is its sponsor, and any number of other members can sign on as cosponsors.1
Does a bill go to the House or Senate first?
Either chamber can go first. There's one exception written into the Constitution: "All Bills for raising Revenue shall originate in the House of Representatives." The Senate can still propose changes to them.21
Step 3: committees, where most bills die
Congress is too big to study every bill as a whole group, so it splits into committees, each covering subjects like farming, courts or education. At the time of Congress's own guide there were 20 standing committees in the House and 16 in the Senate.1 A committee can:
- hold public hearings, where experts and officials answer questions,
- hold a markup, where members debate and amend the bill line by line,
- vote to report the bill to the full chamber, or set it aside ("table" it) or simply never act.1
Most bills stop right here. In the 2023–2024 Congress, 17,565 of 19,315 bills and resolutions (about 91%) went no further than introduction or committee.9 Congress's guide calls committee action "perhaps the most important phase of the legislative process".1
Steps 4–5: votes in the House and the Senate
The two chambers are built differently, and so are their votes.14
If the Senate is split 50–50, the Vice President, who is the President of the Senate, can cast the tie-breaking vote.2
What is a filibuster?
The Senate has a tradition of unlimited debate. A filibuster is when senators use that to drag out debate and delay or block a vote.5 To end it, the Senate votes for cloture. Since 1975, cloture has needed three-fifths of the Senate, which is 60 of 100 senators. (From 1917 to 1975, it took two-thirds of those voting.)5 That's why many bills in practice need 60 senators on board, not just 51.
Step 6: making both versions match
A bill can only go to the President once both chambers have passed identical text.6 If the Senate changes the House's bill (or the other way round), there are two ways to fix it:1
- Back and forth: one chamber agrees to the other's changes, or amends them again and sends them back, until both agree.
- Conference committee: a small group of members from both chambers meets to write one compromise version. Then both chambers vote on it again.14
The final text is printed as the enrolled bill, on parchment paper, and is sent to the White House.1
Step 7: what can the President do with a bill?
Article I, Section 7 of the Constitution gives the President three options.21
A law usually takes effect on the day it's approved, unless the bill sets a different date.1
Step 8: how does Congress override a veto?
To override a veto, two-thirds of the members voting in the House and two-thirds of those voting in the Senate must vote to pass the bill again, in a recorded vote.21 If all members vote, that's 290 representatives and 67 senators. It's rare: presidents have vetoed 2,599 bills since 1789 (1,533 regular vetoes and 1,066 pocket vetoes), and Congress has overridden just 112.7
After a bill becomes law, the National Archives' Office of the Federal Register gives it a public law number and publishes it, first as a "slip law" and later in the Statutes at Large.8
Why is it so hard to pass a law?
On purpose. Each gate is a check. House members are elected every two years, senators serve six-year terms, and the President serves four years.2 Both chambers must agree, and the President can stop a bill unless two thirds of both chambers override the veto. It means a law usually needs support from lots of different people, elected at different times.
States work in a similar way. Every state has its own legislature and a governor, and every state except Nebraska has two chambers.10 Presidents are chosen by a different process, too: see how the Electoral College works.
Common misconceptions
"Every bill starts in the House." Bills can start in either chamber. Only revenue (tax) bills must start in the House.
2
"If the President ignores a bill, it dies." Usually the opposite: after 10 days (Sundays excepted) it becomes law. It only dies if Congress has adjourned so the bill can't be returned: a pocket veto.
1
"51 votes always passes a bill in the Senate." A majority passes it, but if senators filibuster, 60 votes are needed first to end debate.
5
"A veto is final." Two-thirds of both chambers can override it, though that has happened only 112 times.
7
"Most bills get a vote." In 2023-2024, about 91% of bills and resolutions never got past introduction or committee.
9
FAQ
What are the steps for a bill to become a law?
A member of Congress introduces the bill. It goes to a committee, which studies it, holds hearings and rewrites it (markup). If the committee approves it, the bill can go to the whole chamber for debate and a vote. The other chamber then does the same. Both chambers must agree on the exact same text, so any differences are worked out. Finally, the bill goes to the President, who can sign it, veto it (Congress can override with two thirds of both chambers), or let it become law without signing.
Can a bill become law without the President signing it?
Yes, in two ways. If the President doesn't sign or veto a bill within 10 days (not counting Sundays) while Congress is in session, it becomes law automatically. And if the President vetoes a bill, Congress can override the veto with a two-thirds vote in both the House and the Senate.
What are the three ways a bill can become a law?
1) The President signs it. 2) The President does nothing for 10 days (Sundays excepted) while Congress is in session. 3) Congress overrides a presidential veto with a two-thirds vote in each chamber.
Does a bill go to the House or Senate first?
Either one. A bill can start in the House or the Senate. The one exception comes from the Constitution: bills for raising revenue (taxes) must start in the House of Representatives. The Senate can still amend them.
Does a bill become law if the President ignores it?
Usually, yes. If Congress is in session and the President neither signs nor returns the bill within 10 days (Sundays excepted), it becomes law. But if Congress has adjourned and the President can't return it, the bill dies. That's called a pocket veto, and Congress can't override it.
How many votes does a bill need to pass?
A simple majority of those voting in each chamber. If all members vote, that's 218 of 435 in the House and 51 of 100 in the Senate. In the Senate, many bills also need 60 votes to end a filibuster (cloture) before the final vote can happen. Overriding a veto takes two-thirds of those voting in both chambers.
Why do most bills never become law?
Most bills are sent to a committee and never get further. In the 2023-2024 Congress, about 91% of the 19,315 bills and resolutions introduced had no action after introduction or committee, and only 274 were enacted as laws.
Sources
- Congress.gov (Library of Congress), How Our Laws Are Made (House Document 110-49)
- National Archives, The Constitution of the United States: A Transcription (Article I, Sections 3 and 7; Article II)
- USAGov, How laws are made
- U.S. House of Representatives, The Legislative Process
- U.S. Senate, About Filibusters and Cloture
- U.S. Senate, Types of Legislation
- U.S. Senate, Vetoes, 1789 to Present
- National Archives (Office of the Federal Register), Public Laws
- GovTrack.us, Statistics and Historical Comparison (118th Congress)
- The White House, State & Local Government