There are several major categories of bills debated and enacted by Congress:

1)  Authorizing bills establish particular programs and outline what the programs intend to accomplish. The language of authorizing legislation often reflects special emphasis or restrictions that Members of Congress wish to include. These laws generally "authorize" the maximum amount of money that may be spent to implement any given program. Thus, the authorized amounts in these bills are the spending "ceilings." Congress may also "earmark," or set aside, money for specific purposes. An earmark establishes a spending "floor," which is often expressed as a percentage or set allotment of the funding provided (e.g., "not less than 7.5% of the funding provided each year shall support programs in general dentistry"). Authorizations generally cover a three to four year time span, although between "reauthorizations," amendments to authorizing bills may be enacted.  

2)  Appropriations bills provide funding for all authorized programs. They specify how much money will actually be spent for a given federal fiscal year (Oct.1 through Sept. 30). Supplemental appropriation bills sometimes become necessary during a fiscal year to cover unforeseen expenses. Congress uses the appropriations process to review the implementation and effectiveness of specific programs, this process is known as “oversight.” Therefore, appropriations committees often enact changes in programs that would appear to fall under the jurisdiction of the authorizing committee.  

3)  Budget bills set the suggested levels of government spending. The budget resolutions do not become law, but are binding on both chambers of Congress. However, budget resolutions may include instructions to the appropriations committees to restrict the setting of funding levels or to the authorizing committees to reduce the deficit by changing authorized funding levels. The budget activity is conducted according to a schedule established by the Congressional Budget Act of 1974, which was altered by the Gramm-Rudman-Hollings Balanced Budget and Emergency Deficit Control Act of 1985 and most recently by the Budget Enforcement Act of 1990. In past years, appropriations committees have had to wait until Congress passed a budget resolution before working on their appropriations bills. The new process allows the full House to consider appropriations legislation any time after May 15, whether or not the budget committees have completed their resolutions.

4) Continuing resolutions are a specific type of appropriations legislation. When Congress and the President of the United States fail to agree on and pass one, or more, of the regular appropriations bills, a continuing resolution may be passed instead. A continuing resolution continues the pre-existing appropriations at the same levels, and under the same terms and conditions (or with minor modifications), as the previous fiscal year. The funding extends until a specific expiration date or until regular appropriations bills are passed, whichever comes first. 

There are numerous sources of legislation. While, a Member of Congress must introduce legislation, organizations like the American Dental Education Association (ADEA) or an agency of the executive branch of government may recommend legislative proposals to individual Members for their introduction. The proposal might address a need, call for a change in existing law or create a new program. A Senator or Representative may introduce legislation at any time when Congress is in session. 

The first step in the legislative process is the introduction of a bill followed by its referral to a committee. Members try to recruit as many cosponsors of a bill as they can prior to introduction. They often aim at bipartisan support and focus first on support from members of the committee to which the bill has been, or will be, referred.

Once a bill is introduced, it is assigned a number and referred to one of the "standing" committees (17 in the Senate, 19 in the House), depending on its content. The committee may then, if necessary, refer the bill to one of its subcommittees. If a bill contains language that involves more than one committee, it may be "jointly" referred to other committees.   

Committees are the heart of the legislative process. The size of the Senate (100) and the House of Representatives (435), in addition to the number of bills pending at a given time, make it extremely difficult for Members to consider each piece of legislation individually. Consequently, each chamber has established a committee and subcommittee system, allowing smaller groups of members to review legislation. Membership ratios on committees between the majority and minority parties are determined at the beginning of each Congress and reflect the party makeup of each chamber. A caucus of the respective parties assigns individuals to committees. The Member of Congress having the most years of service on a committee is often given the first right of refusal to chair a committee. The Member of the minority party with the most seniority is usually designated as the "Ranking Minority Member."

The chairman of a committee or subcommittee is a dominant figure in the legislative process because he or she determines which issues are considered and the pace at which legislation proceeds. Each year, many bills are introduced. Most of these will never become law because they do not have sufficient Congressional support. The committees and subcommittees control whether a bill will be given a hearing, thereby increasing the chances for that legislation to garner additional support.

Members of Congress have professional staff to assist them with their work, both on their personal staff and for their committee assignments. The generic term "congressional staff" is also used to describe those who work in the various "arms" of the legislative branch, e.g., the Congressional Budget Office (CBO) or the Congressional Research Service (CRS). The degree to which a Member of Congress depends upon his or her staff varies greatly. However, it is generally true that congressional staff play an important role in the legislative process. It is therefore imperative to establish and maintain good working relationships with staff.

Once a legislative proposal is developed, hearings may be held. The hearings provide the opportunity for representatives of executive branch agencies, interested organizations and individuals to formally present their views on a given topic. Members of Congress also convene "oversight" hearings to monitor and evaluate the execution of various laws so they can see if additional or modified legislation is necessary and "impact" hearings to determine the effect of a particular policy on a given group of people.

The step following a hearing is a subcommittee "mark up," where a bill is amended to reflect concerns or issues revealed in the public hearings and to include other modifications made by Members of Congress. The bill then advances to the full committee level where a similar process takes place. When the full Committee completes its "mark up," the bill is "reported out" to the House or Senate for a floor vote. The term “reported out” comes from the fact that a report usually accompanies a bill from a committee. The report generally outlines the legislative history and describes congressional intent. Because laws are sometimes written in vague language to allow flexibility in program administration, the legislative intent becomes important when the executive branch agencies are writing the regulations to implement a law. 

There are several procedural steps that must be taken prior to a bill going to the floor of the House or Senate for a vote. In the House, a bill must first be granted a "rule" by the Rules Committee. The rule establishes how much time will be allotted for debate and what types and how many amendments may be offered. In the Senate, a bill may be debated endlessly with no limit on the number of amendments. Two ways that the Senate often limits legislative debate on a bill is through a “unanimous consent agreement” to which both the minority and majority leadership agree to set limits for debate. In some cases, a move to invoke "cloture" may be used to close debate but must be approved by 60 votes. Cloture is the only way to stop a filibuster.

Once a bill is passed on the floor, it is sent to the other chamber for its consideration. Rarely do both chambers pass identical bills. If both bills are the same, they can be sent directly to the President. If they are dissimilar, they go to a "conference committee," comprised of Members selected by each chamber, who fashion a compromise. Conferees are generally limited during their deliberations by what is contained in each of the bills, i.e., they cannot insert an issue beyond what has already been approved by one of the two chambers. If the conferees are unable to agree, the bill effectively "dies" in conference. When a conference committee reaches agreement, the bill returns to the floor of the House and Senate where members vote for or against the final bill.  

After a bill is formally "enrolled" (written on parchment), it is sent to the President for action. The President, who has 10 days from the time it reaches his desk to act, has four options:

• Sign the bill, enacting it into law;
• Formally veto the bill within 10 days after receiving it;
• Allow the bill to become law without his signature by not acting on it within the established 10-day period; or  
• “Pocket veto” the bill by doing nothing at the end of the second session of a Congress, where the 10-day period extends beyond the date of the final adjournment of Congress.