RSMo stands for the Revised Statutes of Missouri, the official compilation of the state’s permanent laws. Every bill passed by the Missouri General Assembly and signed by the Governor is eventually folded into this code, organized by subject so you can look up a specific rule by number. RSMo covers criminal penalties, family law, taxation, public health, commercial transactions, and nearly every other area the state regulates. The current text is maintained online by the Revisor of Statutes at revisor.mo.gov.1Missouri Revisor of Statutes. Missouri Revisor of Statutes
How to Read an RSMo Citation
A typical citation looks like “Section 571.030, RSMo.” The number before the decimal is the Chapter, and the digits after the decimal identify the specific Section within that Chapter. Section 571.030, for example, sits in Chapter 571 (weapons offenses) and covers unlawful use of weapons.2Missouri Revisor of Statutes. Missouri Code 571.030 – Unlawful Use of Weapons, Offense of – Exceptions – Violation, Penalties The decimal system gives the Revisor room to insert new laws between existing ones without renumbering the whole code; a new provision between 100.010 and 100.020 can simply be assigned 100.015.
In formal legal writing, Missouri citations follow Bluebook form: “Mo. Rev. Stat. §” followed by the section number and year. For everyday research, the plain section number is all you need to pull up the right law online.
One thing to watch for: penalties often live in a different Chapter than the offense itself. A criminal section may define the conduct, but the sentencing range and maximum fine sit in Chapter 558. A Class D felony, for instance, carries up to seven years in prison and a fine of up to $10,000, set by Sections 558.011 and 558.002.3Missouri Revisor of Statutes. Missouri Code 558.011 – Sentence of Imprisonment, Terms – Conditional Release4Missouri Revisor of Statutes. Missouri Code 558.002 – Authorized Fines Reading only the section that defines the offense will leave you with half the answer.
How the Code Is Organized
RSMo uses three tiers: Titles, Chapters, and Sections. Titles are the broadest grouping. Title XXXVIII, for example, covers Crimes and Punishment along with provisions for peace officers and public defenders.5Missouri Revisor of Statutes. RSMo Title XXXVIII Within each Title, Chapters narrow the focus. Chapter 565 deals specifically with offenses against the person, such as assault and invasion of privacy.6Missouri Revisor of Statutes. RSMo Chapter 565 Offenses Against the Person
Inside each Chapter, individual Sections contain the actual legal rules. A Section may define an offense, set a penalty, list exceptions, or establish a procedure. Many Sections also include numbered subsections in parentheses that add definitions or carve out exceptions. You can start broad at the Title level and drill down to the exact provision you need, or jump straight to a Section if you already know the number.
When a Law Takes Effect
Timing matters more than most people expect. The Missouri General Assembly meets from early January through mid-May.7Missouri House of Representatives. Missouri House of Representatives – Session Once a bill passes both chambers and the Governor signs it, the new law does not take effect immediately. Legislation becomes effective ninety days after the session adjourns, which in practice typically falls on August 28.8Missouri Revisor of Statutes. Missouri Code 1.130 – Effective Date of Laws The legislature can override this default with an emergency clause, which requires a two-thirds vote in each chamber and makes the law effective on the date the Governor signs it.
Between full republications of the bound volumes, the Committee on Legislative Research publishes cumulative supplements, or pocket parts, that capture recent amendments, new enactments, and repeals.9Missouri Revisor of Statutes. Missouri Code 3.125 – Publication of Supplements or Pocket Parts Relying on an outdated volume without checking the supplement is one of the most common research mistakes. The online version at revisor.mo.gov updates each section on its effective date, which makes it far more reliable than a physical book that may be years old.
Chapters can also be repealed or moved. Missouri’s controlled substance offenses, for example, were largely transferred from Chapter 195 to Chapter 579 as part of a comprehensive criminal code reorganization that took effect in 2017.10Missouri Revisor of Statutes. Missouri Code 579.020 Anyone researching drug offenses using a pre-2017 source would end up in the wrong chapter entirely. For disputes involving past events, the version of the law in effect at the time of the conduct is the one that applies, and the Revisor’s site keeps archived versions available for exactly that reason.
Statutes Are Not the Only Rules
RSMo is not the complete picture of binding Missouri law. State agencies also issue administrative regulations, compiled in the Missouri Code of State Regulations (CSR) and published by the Secretary of State.11Missouri Secretary of State. Missouri Code of State Regulations Title 19 Statutes are the broad directives passed by the legislature. Regulations are the detailed rules that agencies write to carry those directives out. A statute might authorize the Department of Health to regulate food safety; the corresponding CSR title fills in the temperature requirements, inspection schedules, and reporting forms.
Regulations carry the force of law once properly adopted, but they cannot exceed the authority granted by the enabling statute. If an agency regulation conflicts with RSMo, the statute controls. When you are researching a legal obligation, checking only the statutes and ignoring the CSR can leave you with an incomplete picture, because the operational details that govern day-to-day compliance often live in the regulations.
How to Look Up a Statute
The official online source for RSMo is revisor.mo.gov, maintained by the Revisor of Statutes.12Missouri Revisor of Statutes. About the Missouri Revisor of Statutes You can search by keyword, browse the table of contents by Title and Chapter, or enter a specific section number directly. The site also offers tools for finding recently changed sections, sections with definitions, and laws that have been repealed or transferred, plus links to recently enacted bills that have passed both chambers but may not yet be reflected in the statutory text.
Third-party legal databases like Westlaw and LexisNexis publish annotated versions of RSMo that include case summaries showing how courts have interpreted each section, cross-references to related regulations, and links to legislative history. These annotations save research time, but they are editorial content, not law. The statutory text on revisor.mo.gov is the authoritative version, and the one Missouri courts treat as official.