Which U.S. states have enacted statewide sanctuary laws and what do those laws require?

1. What “sanctuary state” means — no uniform legal definition

There is no agreed federal statutory definition of what makes a state a “sanctuary” jurisdiction, and different organizations apply different criteria when counting states, which drives the variation in reported totals and lists ^{[3] [1]}. Congress’s legal overviews note two recurring policy types that draw attention: limits on sharing immigration-related information with federal authorities, and prohibitions on honoring ICE detainers or transferring jailed people to ICE custody — but states craft these rules in many permutations ^[4].

2. Which states are most often identified as sanctuary states and why

Advocacy groups that track sanctuary policies report that about 17 states plus D.C. have statewide sanctuary laws, policies, or formal legal opinions; examples frequently cited among strong statewide protections include California, Oregon, and Washington, where statutes and executive rules restrict local cooperation with federal immigration actions ^{[1] [6]}. Illinois adopted the Illinois Trust Act and is named in reporting as a sanctuary state after passage of that law ^[7]. Exact state-by-state listings vary by source because some count formal statutes while others include attorney‑general opinions or administrative rules ^{[2] [1]}.

3. What these statewide laws typically require or prohibit

Across the statutes and policies identified, common provisions include restrictions on sharing nonpublic immigration status information with ICE, bans or limits on honoring ICE civil immigration detainers without a judicial warrant, prohibitions on local participation in certain federal enforcement programs (such as 287(g) or jail‑to‑ICE transfer agreements), and limits on using state funds for general immigration enforcement ^{[4] [5] [8]}. Some states explicitly bar state agencies from entering contracts that deputize state or local officers to enforce federal immigration law; others focus more narrowly on jail transfer procedures and data‑sharing practices ^{[5] [4]}.

4. How counts and lists differ — methodology matters

Trackers disagree: the Center for Immigration Studies and FAIR publish different tallies and include different jurisdictions based on whether they count local ordinances, state statutes, or policy statements, producing lists that can show 13, 17, or other numbers of sanctuary states depending on criteria ^{[9] [10] [1]}. The Library of Congress’s legal analyses highlight that because methodologies diverge, one should read any list’s criteria before accepting its count ^[3].

5. Enforcement, legal conflicts, and federal responses

The federal government has responded by compiling lists of jurisdictions it says impede enforcement and by initiating litigation against some cities and states, signaling that designation and enforcement are contested and evolving matters ^{[11] [12]}. Courts and state charters sometimes complicate statewide enforcement: for example, California’s state statutes have been challenged in lawsuits by charter cities, illustrating how local‑state legal interplay can blunt or change how a state law operates on the ground ^[13].

6. Debate and practical implications

Supporters of statewide sanctuary laws frame them as public‑safety and civil‑rights measures meant to increase trust in policing and protect families from civil immigration enforcement by limiting local cooperation ^{[6] [8]}. Opponents argue such laws undercut federal immigration enforcement and public safety, and organizations opposed to sanctuary policies publish alternative lists and legal arguments to that effect ^{[6] [10]}. Reporting and legal analyses make clear the debate is political and legal as much as it is administrative, and that the substance of “what a sanctuary law requires” depends on statutory wording and how courts and agencies treat those provisions ^{[3] [5]}.