Across the U.S. each state has set up its own way of managing legislation and organizing the process of making new laws. Legislation generally has to be introduced and make its way through the legislature within a specific session to be successful. But every state does it differently!
To help make sense of it all, below is some broad information about how states tend to do it and how that affects BillTrack50 bill searching and filtering using the timeline. And at the bottom, handy information on each state. For more detailed information on current sessions, including any special sessions, see this document from our partner Legiscan. Also check out this great summary of session dates and rules and an excellent glossary from Ballotpedia.
For more detail on how to make searches across multiple years / sessions, see this help post.
Annual (one year) sessions
About half the states have a session every year. Some states have regular sessions every other year, and only financial or organization sessions in the off years. In all of these cases, the session is contained within one calendar year, so your search by year will act exactly how you expect it to - it will include regular sessions active in the calendar years you have chosen.
Biennial (two year) sessions
About half of the states have two-year sessions (or a 'biennium'), with all but New Jersey running from an odd year to an even year. For example, the 118th Congress, runs 2023-2024. New Jersey, the exception, runs even year to odd year, except it doesn't finish until the following January, so in 2024-2025, the session actually runs until Jan 2026. For our purposes, we consider their session to be contained within the two years.
Virginia also technically has even to odd year biennials, but because it re-introduces bills in the second year we treat it as if it is a single year state.
If your search overlaps just one year of a two year session then we include all bills from the entire session, not just bills from the overlapping year. For example, the search covering 2020 - 2024 pictured above would overlap one year of, say, California’s 2019-2020 session. So you would see bills introduced in 2019 because they were potentially still alive in 2020. We feel keeping whole sessions together in this way will give you the most relevant results.
Unfortunately, again using the example above, the search would overlap New Jersey’s 2024-2025 session, so you would get back all bills from that session, including those introduced in 2025. That may be initially confusing, but again, we feel showing you whole sessions is important. Luckily we also have a “created” date as a choice as a template column, so you can sort by that date and easily knock out 2025 bills if you want to. See this post for how to develop templates for the columns you want to see in your bill sheet.
Every other year sessions
Texas, Nevada, North Dakota, and Montana meet every other year, on odd years. These are one year sessions, so we treat them as simply contained within their year. Thus a search for just a single even year will not result in any bills being shown from these states.
Special Sessions
Special sessions are called by the Governor, within the provisions laid down in the state constitution. They are usually called while the regular session is adjourned, but can exceptionally be during a regular session. They are usually limited in length and have to focus on a single topic (often agreeing a budget) or a narrow set of topics. Special sessions are always contained within a single year. So even in two year states, we will show you only the special sessions that took place in the years you are covering — bills from a special session in 2023 won’t ever be relevant to a 2024 search, so we don’t think we should show them to you.
Carry Over
Some states with one year sessions allow bills to be “carried over” into the next session. In some of these states, carried over bills get a new bill number, but in all states, carried over bills are given a new URL on the state legislature website. We treat these bills as “new” because really, they are. Granted, they start their life identical to their old version, and they usually have some amount of head start through the process; but in database terms, they are reintroduced and have their own new life. We give these bills a new internal Bill ID, and a new row in our bill table. So if you have queries with keywords, you will get “new bill” alerts when the bills are reintroduced, and we won’t keep updating the old version of the bill from the previous year.
The action history on a carried over bill will give you a heads up about what is going on. If you look at the state legislature website for each bill you’ll see what we’ve chosen to do with the bill is pretty much the same as what the state is doing (which isn’t really a coincidence).
Pre-Filing
Some states allow bills to be filed before the session begins, or “pre-filed”. If a legislature begins posting bills before the official beginning of the session, we want to share these bills with you as soon as possible (which is as soon they are assigned a bill number; we don’t capture them while they are still study documents or other not-quite-a-bill documents).
For the purposes of the search, bills that are pre-filed are evaluated based on the session they are part of, not the calendar year we received them. So if bills are pre-filed in December 2023 for a 2024 session, they will show up in a search covering 2024, but not a search ending in 2023.
All The Basics In One List
Here's some basic information about individual states and the length of their sessions. Remember, for more detail look at the annual breakdown published by Legiscan or the Ballotpedia analysis.
Biennial Sessions
The following states have 'biennium' sessions that last two years, and run odd years to even.
And this state runs even years to odd.
Annual Sessions
The following states have sessions that run every year. The start month may vary, and fall within a period (Jan. - Mar.) or be a certain month on odd years and a different month on even years (Jan. / Feb.)
Every Other Year Sessions
The following states only have session in odd numbered years.
