Understanding Congress

How Laws Are Made

An idea becomes a bill. Congress debates and changes it. Both the House and Senate must agree on the same text before sending it to the president.

This page explains federal laws. State legislatures and local governments have their own lawmaking procedures. A bill is a proposal; it is not yet a law.

The short version

  1. Introduce a bill. A member of Congress formally proposes legislation.
  2. Work through Congress. Lawmakers study, debate, amend, and vote. Both chambers must pass identical text.
  3. Send it to the president. A signature makes it law. It can also become law without a signature or through a congressional veto override.

A court’s approval is not required for a bill to become law.

From an idea to a bill passed by Congress

This is the usual path. Bills do not all receive hearings or votes, and some move through special procedures.

  1. An idea becomes a proposal

    Ideas may come from voters, community groups, businesses, researchers, the president, or lawmakers themselves. A crisis, court ruling, or public campaign can bring an issue to Congress’s attention.

  2. A member introduces a bill

    A sponsor introduces the written proposal. A House bill is labeled H.R. and a Senate bill S., followed by its number. Bills can generally start in either chamber; bills for raising revenue must originate in the House.

  3. Committees examine it

    Bills are referred to committees with responsibility for the topic. Committees may hold hearings, hear testimony, and revise the text in a meeting called a markup. They decide whether to recommend a bill to the full chamber. Many bills receive no further action.

  4. The first chamber debates and votes

    If the bill reaches the floor, lawmakers debate it and may consider amendments. Passing an ordinary bill generally requires a majority of those voting, with a quorum present.

    Why do you hear “60 votes” in the Senate? Ending debate on most legislation through cloture requires three-fifths of senators duly chosen and sworn—normally 60. That is a separate hurdle from the final passage vote. Some procedures, such as budget reconciliation, limit debate and work differently.

  5. The other chamber considers it

    The other chamber can pass the bill, change it, or decline to act. Related proposals may also be moving through both chambers at the same time.

  6. Both chambers agree on identical text

    If the versions differ, the chambers must settle those differences. They may exchange amendments or use a conference committee. Both must approve the same final wording before the bill goes to the president.

Sources: House legislative process; Senate filibusters and cloture; Congressional Research Service: resolving differences (PDF).

What can the president do?

Once the bill is presented to the president, the Constitution provides a 10-day period, excluding Sundays.

Sign it

The bill becomes law.

Return it with a veto

The president sends it back to the chamber where it originated, with objections. Congress can reconsider it and attempt an override.

Take no action: it becomes law

If the president neither signs nor returns the bill within the 10-day period, it becomes law—unless Congress’s adjournment prevents its return.

Take no action: a pocket veto

If Congress adjourns in a way that prevents the bill’s return, and the president does not sign it within the 10-day period, it does not become law. A pocket veto cannot be overridden.

Overriding a returned veto takes two-thirds in each chamber.

That means two-thirds of members voting in the House and two-thirds voting in the Senate, with a quorum present in each. If both votes succeed, the bill becomes law without the president’s signature.

Sources: Constitution, Article I, Section 7; House history: presidential vetoes.

After the bill becomes law

Putting the law into practice

A law may take effect immediately or set later dates for particular provisions. Agencies may need to administer programs, issue rules within their legal authority, or enforce requirements.

Possible court challenges

In a case properly before them, courts can interpret a law and decide whether it violates the Constitution. Some challenges reach the Supreme Court. Judicial review is separate from Congress’s passage of the bill.

Source: U.S. Courts: court role and structure.

Why bills stall—or change along the way

There is no guaranteed timetable. Committee priorities, floor schedules, disagreements over cost or wording, Senate debate rules, and a threatened veto can all affect progress.

Agreement can take time

Negotiation can bring more viewpoints into a proposal and help catch problems. It can also produce delays, compromises, or gridlock. Broad agreement can allow Congress to act quickly.

A proposal can survive in another bill

Text from one proposal may be incorporated into a larger bill. Counting only bills that become law under their original numbers does not capture every idea Congress eventually adopts.

Most introduced bills do not become law. A bill that remains unfinished at the end of a two-year Congress does not carry over into the next Congress; it must be introduced again to continue as a bill.

Further reading: Congress.gov: How Our Laws Are Made.

A real example: the Civil Rights Act of 1964

This law followed years of civil rights organizing and a prolonged fight in Congress. Its path shows how debate, amendments, and agreement between the chambers fit together.

A little over a year from introduction to enactment. The House’s acceptance of the Senate version meant a conference committee was not needed.

Source: U.S. Senate: Civil Rights Act chronology.

Sources & further reading

A simplified guide based on official constitutional, congressional, and court resources.