Editing Interstate compact

{{short description|Formal agreement between two or more U.S. states}}
In the [[United States]], an '''interstate compact''' is a pact or agreement between two or more [[U.S. state|states]], or between states and any foreign sub-national government. 

== Description ==
Most early interstate compacts resolved boundary disputes, but since the early 20th century, compacts have increasingly been used as a tool of state cooperation and mutual recognition on infrastructure, services and professional licensing, often to ease administrative barriers and reduce costs and litigation.<ref name=":0" /> In some cases, an agreement will create a new multi-state [[special-purpose district|governmental agency]] which is responsible for administering or improving some shared resource such as a [[seaport]] or [[public transportation]] infrastructure. Compacts may also be limited to a certain multi-state region, may be open to all states and insular areas, or may be open to subnational governments in other countries. 

Interstate compacts are distinct from, but may involve aspects of, the following: 

* [[Model act|Model acts]], which are proposed [[statute]]s produced by non-governmental bodies of legal experts to be passed by state legislatures independently, rather than constituting an agreement among multiple states; 
* [[Executive agreement|executive agreements]] between governors or statewide executive officers of states, which may or may not have the backing of statute or state constitutional law;
* State-level [[Trigger law|trigger laws]] which provide for an automatic action if another one or more states, or the federal government, perform a specified action; or
* State-level laws mandating, permitting or prohibiting state cooperation with another state government or the federal government regarding certain actions.

=== Interstate agencies ===
Several interstate compacts may establish multi-state agencies in order to coordinate policy between, or perform tasks on behalf of, member states. Such agencies may take the form of commissions, with at least one representative from a member state with a voting role in the commission. Alternatively, member states to a compact may opt for cooperation with a single independent non-profit organization which carries out designated tasks without government funding. Actions or rules changes taken by commissions or non-profits may require ratification by the member states to take effect, depending often on whether such actions may alter the terms of the compact.  

== Legal background ==
The Compact Clause ([[Article One of the United States Constitution#Clause 3: Compact Clause|Article I, Section 10, Clause 3]]) of the [[United States Constitution]] provides that "No State shall, without the Consent of [[United States Congress|Congress]],... enter into any Agreement or Compact with another State, or with a foreign Power,..."<ref name="YLJ319">{{cite journal| title=The Power of the States to Make Compacts| journal=The Yale Law Journal| volume=31| issue=6| date=April 1922| pages=635–639| publisher= The Yale Law Journal Company| doi=10.2307/788529| jstor=788529}}</ref>

However, in a report released in October 2019 about the proposed [[National Popular Vote Interstate Compact]], the [[Congressional Research Service]] (CRS) cited the [[Supreme Court of the United States|U.S. Supreme Court]]'s ruling in ''[[Virginia v. Tennessee]]'' (1893)—reaffirmed in ''[[U.S. Steel Corp. v. Multistate Tax Comm'n|U.S. Steel Corp. v. Multistate Tax Commission]]'' (1978) and ''[[Cuyler v. Adams]]'' (1981)—that ruled that explicit congressional consent of interstate compacts is not required for agreements "which the United States can have no possible objection or have any interest in interfering with" (in addition to ruling that the words "agreement" and "compact" used in the Compact Clause are synonyms).{{sfn|Neale|Nolan|2019|pp=22–23}} Instead, the Court required explicit congressional consent for interstate compacts that are "directed to the formation of any combination tending to the increase of political power in the States, which may encroach upon or interfere with the just supremacy of the United States"—meaning where the [[Balance of power (federalism)|vertical balance of power]] between the federal government and state governments is altered in favor of state governments,{{sfn|Neale|Nolan|2019|p=24}} while the report references ''U.S. Steel Corp. v. Multistate Tax Commission'' as stating that the "pertinent inquiry [with respect to the Compact Clause] is one of potential, rather than actual, impact on federal supremacy" in noting that the potential erosion of an [[Enumerated powers (United States)|enumerated power]] of the [[United States Congress]] by an interstate compact can arguably require explicit congressional approval.{{sfn|Neale|Nolan|2019|p=24}}<ref name="U.S. Steel Corp. v. Multistate Tax Commission">{{cite web|title=United States Steel Corp. v. Multistate Tax Comm'n, 434 U.S. 452 (1978)|website=[[Justia]]|url=https://supreme.justia.com/cases/federal/us/434/452/|access-date=December 23, 2022}} {{PD-notice}}</ref> The CRS report cites the Supreme Court's rulings in ''[[Florida v. Georgia (1855)|Florida v. Georgia]]'' (1855) and in ''[[Texas v. New Mexico and Colorado]]'' (2018) as recognizing that explicit congressional consent is also required for interstate compacts that alter the horizontal balance of power amongst state governments.{{sfn|Neale|Nolan|2019|pp=24–25}}

Citing ''[[Metropolitan Washington Airports Authority v. Citizens for Abatement of Aircraft Noise, Inc.]]'' (1991) as stating that if an enumerated power under the Constitution is legislative, then "Congress must exercise it in conformity with the [[bicameralism]] and [[Presentment Clause|presentment requirements]] of [[Article One of the United States Constitution#Section 7: Bills|Article I, Section VII]]", and noting that the [[Republican River#Republican River Compact|Republican River Compact]] was initially [[Veto power in the United States|vetoed]] by [[President of the United States|President]] [[Franklin D. Roosevelt]] in 1942, the CRS report states that if an interstate compact requires explicit congressional approval, it must be approved by both houses of Congress and signed into law by the President in order to become law.{{sfn|Neale|Nolan|2019|p=26}} In ''Cuyler v. Adams'', the Court held that congressional approval of interstate compacts makes them [[Law of the United States#Federal law|federal law]]s.<ref name="Cuyler v. Adams">{{cite web|title=Cuyler v. Adams, 449 U.S. 433 (1981)|website=[[Justia]]|url=https://supreme.justia.com/cases/federal/us/449/433/|access-date=December 23, 2022}} {{PD-notice}}</ref><ref>{{cite journal|last=Drake|first=Ian J.|date=September 20, 2013|title=Federal Roadblocks: The Constitution and the National Popular Vote Interstate Compact|journal=[[Publius (journal)|Publius: The Journal of Federalism]]|publisher=[[Oxford University Press]]|volume=44|issue=4|pages=691–694|doi=10.1093/publius/pjt037}}</ref> The CRS report cites the Court's opinions in ''Virginia v. Tennessee'' and ''[[Bank of New England#Formation and interstate growth|Northeast Bancorp v. Federal Reserve Board of Governors]]'' (1985) as stating that any agreement between two or more states that "cover[s] all stipulations affecting the conduct or claims of the parties", prohibits members from "modify[ing] or repeal[ing] [the agreement] unilaterally", and requires "'reciprocation' of mutual obligations" constitutes an interstate compact.{{sfn|Neale|Nolan|2019|pp=23–24}} Additionally, the CRS report cites the Court's opinion in ''Northeast Bancorp'' as suggesting that a requirement of a new interstate governmental entity is a [[Necessity and sufficiency|sufficient condition]] for an agreement to qualify as being an interstate compact under the Compact Clause.{{sfn|Neale|Nolan|2019|pp=22–23}} The CRS report stated that there were approximately 200 interstate compacts in effect in 2019.{{sfn|Neale|Nolan|2019|p=22}}

The timing for Congressional consent is not specified by the Constitution, so consent may be given either before or after the states have agreed to a particular compact. The consent may be explicit, but it may also be inferred from circumstances. Congress may also impose conditions as part of its approval of a compact.<ref name=":0">{{Cite web|url=https://constitution.congress.gov/browse/essay/artI_S10_C3_3/%22interstate%20compacts%22/|title=Compacts Clause {{!}} Constitution Annotated {{!}} Congress.gov {{!}} Library of Congress|website=constitution.congress.gov|language=en|access-date=2020-04-14|archive-date=2021-09-03|archive-url=https://web.archive.org/web/20210903230930/https://constitution.congress.gov/browse/essay/artI_S10_C3_3/%22interstate%20compacts%22/|url-status=dead}}</ref> Congress must explicitly approve any compact that would give a state power that is otherwise designated to the [[Federal government of the United States|federal government]].<ref name=NCICpdf>{{cite web| title=Interstate Compacts Fact Sheet| url=https://www.csg.org/knowledgecenter/docs/ncic/FactSheet.pdf| website=csg.org| publisher=National Center for Interstate Compacts| location=Lexington, Kentucky| access-date=April 19, 2020 |archive-url=https://web.archive.org/web/20210310081539/https://www.csg.org/knowledgecenter/docs/ncic/FactSheet.pdf |archive-date=March 10, 2021 |url-status=dead}}</ref>

==History==
Treaties between the states, ratified under the [[Articles of Confederation]] during the period after [[American independence]] in 1776 until the current U.S. Constitution was ratified in 1789, are [[grandfathered]] and treated as interstate compacts.  This includes agreements like the [[Treaty of Beaufort]], which set the [[Border|boundary]] between [[Georgia (US)|Georgia]] and [[South Carolina]] in 1787, and is still in effect.

Prior to 1922, most interstate compacts were either border agreements between states or advisory compacts, the latter of which are tasked with conducting joint studies to report back to the respective state legislatures. With the creation of the [[Port Authority of New York and New Jersey]] in 1922, administrative compacts began to develop as a third, more-empowered type of interstate compact, in which persistent governance structures are tasked by member states with conducting designated services.

Today, Virginia is a member of the most interstate compacts at 40, while Hawaii is a member of the fewest at 15.<ref>{{cite web| title=Interstate Compacts: Background, History and Modern Use| url=http://knowledgecenter.csg.org/kc/system/files/Compacts%20Background.pdf| website=csg.org| publisher=National Center for Interstate Compacts| location=Lexington, Kentucky| access-date= |archive-url=https://web.archive.org/web/20210904070613/http://knowledgecenter.csg.org/kc/system/files/Compacts%20Background.pdf |archive-date=September 4, 2021 |url-status=dead}}</ref>

== List of operating agencies created by interstate compact==
===Borders and land/water administration===
*[[Atlantic States Marine Fisheries Commission]] ([[Maine]], [[New Hampshire]], [[Massachusetts]], [[Rhode Island]], [[Connecticut]], [[New York (state)|New York]], [[New Jersey]], [[Pennsylvania]], [[Delaware]], [[Maryland]], [[Virginia]], [[North Carolina]], [[South Carolina]], [[Georgia (U.S. state)|Georgia]], and [[Florida]])<ref name="asmfc-aboutus">{{cite web
 |url=http://www.asmfc.org/aboutUs.htm
 |archive-url=http://webarchive.loc.gov/all/20040427210450/http://www.asmfc.org/aboutUs.htm
 |url-status=dead
 |archive-date=2004-04-27
 |title=Atlantic States Marine Fisheries Commission: About Us 
 |access-date=2009-06-23 
}}</ref>
*Bear River Commission (Idaho, Utah and Wyoming)
*[[Breaks Interstate Park]] Commission ([[Kentucky]] and [[Virginia]])<ref>{{cite web|url=https://ballotpedia.org/Breaks_Interstate_Park_Compact|title=Breaks Interstate Park Compact – Ballotpedia}}</ref>
*[[Colorado River Compact]] ([[Colorado]], [[New Mexico]], [[Utah]], [[Wyoming]], [[Nevada]], [[Arizona]], and [[California]])<ref name="usbr.gov">[http://www.usbr.gov/lc/region/pao/pdfiles/ucbsnact.pdf Upper Colorado River Basin Compact of 1948], U.S. Bureau of Reclamation, 1948</ref>
*[[Columbia River Gorge Commission]] ([[Oregon]] and [[Washington (state)|Washington]])
*[[Connecticut River#1614–1636: Dutch and Puritan settlement|Connecticut River Valley Flood Control Commission]] ([[Connecticut]], [[Massachusetts]], [[New Hampshire]], and [[Vermont]])<ref>{{cite web|url=http://www.crvfcc.org|title=Connecticut River Valley Flood Control Commission – Monitoring flood control dams in the CT River valley}}</ref>
*[[Delaware River Basin Commission]] ([[Pennsylvania]], [[Delaware]], [[New Jersey]], and [[New York (state)|New York]])<ref>{{cite web|url=http://www.nj.gov/drbc/about/accomplishments.html|title=Delaware River Basin Commission-Milestones|last=csebestyen}}</ref>
*[[Delaware River Port Authority]] ([[Pennsylvania]] and [[New Jersey]])<ref>{{cite web|url=http://www.drpa.org/drpa/history.html|title=DRPA :: Delaware River Port Authority|access-date=2013-08-11|archive-url=https://web.archive.org/web/20090326225427/http://www.drpa.org/drpa/history.html|archive-date=2009-03-26|url-status=dead}}</ref>
*[[Delaware River and Bay Authority]] ([[Delaware]] and [[New Jersey]])
*[[Great Lakes Commission]] ([[Illinois]], [[Indiana]], [[Michigan]], [[Minnesota]], [[New York (state)|New York]], [[Ohio]], [[Pennsylvania]], and [[Wisconsin]], plus [[Provinces and territories of Canada|Canadian provinces]] of [[Ontario]] and [[Quebec]] as associate members)
*[[Gulf States Marine Fisheries Commission]] ([[Alabama]], [[Florida]], [[Louisiana]], [[Mississippi]], and [[Texas]])
*[[Interstate Commission on the Potomac River Basin]] ([[Maryland]], [[West Virginia]], [[Virginia]], [[Pennsylvania]], and [[District of Columbia]])<ref>{{cite web|url=http://www.potomacriver.org|title=Home – ICPRB}}</ref>
*[[Interstate Environmental Commission]] ([[Connecticut]], [[New Jersey]] and [[New York (state)|New York]]) <ref>{{cite web|url=http://www.iec-nynjct.org|title=Interstate Environmental Commission|first=Yankee Planning Group|last=LLC}}</ref>
*[[Interstate Wildlife Violator Compact]] (all states except [[Hawaii]] and [[Massachusetts]])
*[https://neiwpcc.org/ NEIWPCC (originally called the New England Interstate Water Pollution Control Commission)] (Connecticut, Maine, Massachusetts, New Hampshire, New York, Rhode Island, Vermont) 
*[[Pacific States Marine Fisheries Commission]] ([[California]], [[Oregon]], [[Washington (state)|Washington]], [[Idaho]], and [[Alaska]])
*[[Palisades Interstate Park Commission]] ([[New York (state)|New York]] and [[New Jersey]])
*[[Red River Compact Commission]] ([[Arkansas]], [[Louisiana]], [[Oklahoma]] and [[Texas]])<ref>{{cite web|url=http://www.owrb.ok.gov/rrccommission/rrccommission.html|title=Red River Compact Commission}}</ref>
*[[Susquehanna River Basin Commission]] ([[Pennsylvania]], [[New York (state)|New York]], and [[Maryland]])
*[[Tahoe Regional Planning Agency]] ([[California]] and [[Nevada]])<ref>{{Cite web|url=https://www.trpa.org/|title=Tahoe Regional Planning Agency — TRPA|website=Tahoe Regional Planning Agency — TRPA|access-date=2020-11-06|archive-date=2022-12-01|archive-url=https://web.archive.org/web/20221201203732/https://trpa.org/|url-status=dead}}</ref>
*Interstate Mining Compact (24 states)

===Transportation===
*[[Bi-State Development Agency]] ([[Missouri]] and [[Illinois]])
*[[Washington Metropolitan Area Transit Authority]] ([[Maryland]], [[Virginia]], and [[Washington, D.C.]])<ref>{{cite web|url=http://wmata.com|title=Home – WMATA}}</ref>
*[[Washington Metropolitan Area Transit Commission]] ([[Maryland]], [[Virginia]], and [[Washington, D.C.]])<ref>{{cite web|url=http://www.wmatc.gov|title=Welcome to the Washington Metropolitan Area Transit Commission}}</ref>
*[[Kansas City Area Transportation Authority]] ([[Kansas]] and [[Missouri]])
*[[Midwest Interstate Passenger Rail Commission]] ([[Illinois]], [[Indiana]], [[Kansas]], [[Michigan]], [[Minnesota]], [[Missouri]], [[Nebraska]], [[North Dakota]], [[Wisconsin]])<ref>{{cite web|url=https://www.csg.org/NCIC/MidwestInterstatePassengerRailCompact.aspx|title=Midwest Interstate Passenger Rail Compact|publisher=National Center for Interstate Compacts (NCIC)|access-date=2018-05-22|archive-date=2021-04-29|archive-url=https://web.archive.org/web/20210429100322/http://www.csg.org/NCIC/MidwestInterstatePassengerRailCompact.aspx|url-status=dead}}</ref>
*[[Port Authority of New York and New Jersey]] ([[New Jersey]] and [[New York (state)|New York]])<ref>{{cite web |title=Port Authority of New York & New Jersey |url=https://panynj.gov}}</ref>
*[[Virginia-North Carolina High Speed Rail Compact]] ([[North Carolina]] and [[Virginia]])<ref>{{cite web|url=http://www.drpt.virginia.gov/rail/major-initiatives/va-nc-high-speed-rail-compact/|title=Virginia-North Carolina High Speed Rail Compact|publisher=Virginia DOT}}</ref>
*[[Delaware River Joint Toll Bridge Commission]] ([[Pennsylvania]] and [[New Jersey]])

===Health and emergency===

*[[Nurse Licensure Compact]] (33 states)<ref>{{Cite web |title=Nurse Licensure Compact (NLC) |url=https://www.ncsbn.org/nurse-licensure-compact.htm}}</ref>
*[[Recognition of EMS Personnel Licensure Interstate CompAct]] (REPLICA, or EMS Compact; 20 states)<ref>{{Cite web |title=Compact History {{!}} EMS Compact |url=https://www.emscompact.gov/the-compact/compact-history |access-date=2024-05-31 |website=www.emscompact.gov}}</ref>
*[[Western States Pact]] ([[California]], [[Colorado]], [[Nevada]], [[Oregon]], [[Washington (state)|Washington]]) <ref>{{cite web |last1=Klar |first1=Rebecca |date=April 27, 2020 |title=Colorado and Nevada join western states cooperating on reopening |url=https://thehill.com/policy/healthcare/494890-colorado-and-nevada-join-western-states-cooperating-on-reopening-after |access-date=July 26, 2020 |work=The Hill}}</ref>
*[[Eastern States Multi-state Council]] ([[New York (state)|New York]], [[New Jersey]], [[Pennsylvania]], [[Massachusetts]], [[Rhode Island]], [[Connecticut]], [[Delaware]])<ref>{{cite web |last1=Lahut |first1=Jake |date=Apr 13, 2020 |title=New York Gov. Cuomo unveils multistate coalition to reopen economy after coronavirus |url=https://www.businessinsider.com/cuomo-launches-multi-state-coalition-to-re-open-economy-post-corona-2020-4?op=1 |access-date=July 26, 2020 |website=Business Insider}}</ref>
*[[Midwest Governors Regional Pact]] ([[Illinois]], [[Indiana]], [[Kentucky]], [[Michigan]], [[Minnesota]], [[Ohio]], [[Wisconsin]])
*[[Emergency Management Assistance Compact]] (all states, plus [[Washington, D.C.]], [[Puerto Rico]], [[U.S. Virgin Islands]], and [[Guam]])
*[[Health Care Compact]]
*[[Interstate Civil Defense and Disaster Compact]]
*[[Social Work Licensure Compact]] ([[Alabama]], [[Connecticut]], [[Georgia (U.S. state)|Georgia]], [[Iowa]], [[Kansas]], [[Kentucky]], [[Maine]], [[Missouri]], [[Nebraska]], [[Ohio]], [[South Dakota]], [[Utah]], [[Vermont]], [[Virginia]], [[Washington (state)|Washington]])<ref>{{cite web | url=https://stateline.org/2024/05/28/amid-mental-health-crisis-new-compact-allows-social-workers-to-practice-across-state-lines | title=Amid mental health crisis, new compact allows social workers to practice across state lines • Stateline | date=28 May 2024 }}</ref>
*Advanced Practice Registered Nurse Compact (Delaware, North Dakota, South Dakota, Utah)<ref>{{Cite web |title=Home |url=https://www.aprncompact.com/ |access-date=2024-05-31 |website=APRNCOMPACT |language=en}}</ref>
*Northeastern Forest Fire Protection Compact (Connecticut, Maine, Massachusetts, New Hampshire, New York, Rhode Island, Vermont)<ref>{{Cite web |last=NFFPC |title=About NECC |url=https://www.nffpc.org/en/necc/about |access-date=2024-05-31 |website=NFFPC |language=en}}</ref>
*Physical Therapy Compact (PT License; 30 states)<ref>{{Cite web |title=PT Compact States Map |url=https://ptcompact.org/ptc-states |access-date=2024-05-31 |website=ptcompact.org}}</ref>
*Psychological Interjurisdictional Compact (PSYPACT; 40 states, including [[Northern Mariana Islands]] and D.C.)<ref>{{Cite web |title=About Us - Psychology Interjurisdictional Compact (PSYPACT) |url=https://psypact.org/page/About |access-date=2024-05-31 |website=psypact.org}}</ref>
*Interstate Medical Licensure Compact (IMLC; 32 states and Guam)<ref>{{Cite web |title=Compact State Map |url=https://www.imlcc.org/participating-states/ |access-date=2024-05-31 |website=Interstate Medical Licensure Compact |language=en-US}}</ref>
*Audiology and Speech-Language Pathology Compact (ALSPCompact; 32 states)<ref>{{Cite web |title=Compact Map – ASLPCompact |url=https://aslpcompact.com/compact-map/ |access-date=2024-05-31 |language=en-US}}</ref>
*Occupational Therapy Compact (OT Compact; 30 states)<ref>{{Cite web |url=https://otcompact.org/compact-map/ |access-date=2024-05-31 |website=otcompact.org}}</ref>
*Counseling Compact (36 states)<ref>{{Cite web |title=Compact Map – Counseling Compact |url=https://counselingcompact.org/map/ |access-date=2024-05-31 |website=counselingcompact.org}}</ref>

=== Economic development ===

* Appalachian Region Interstate Compact (Virginia, West Virginia)
* [[Pacific Northwest Economic Region]] (States of Alaska, Idaho, Montana, Oregon, Washington, with the Canadian jurisdictions of Alberta, Saskatchewan, British Columbia, Northwest Territories)
* Interstate Compact on Licensure of Participants in Horse Racing with Pari-Mutuel Wagering (15 states)
* Southern Growth Policies Compact (12 states)

=== Education ===

*[[Rivendell Interstate School District]] (New Hampshire, Vermont)
*[[Dresden School District]] (New Hampshire, Vermont)
*[[Education Commission of the States]] (all states [except Washington State]; three territories; and [[Washington, D.C.]])<ref>{{cite web |date=c. 2011 |title=ECS Officers and President:ECS Officers for 2011-13 |url=http://www.ecs.org/html/aboutECS/ECS_exec_mgt_bios.htm |url-status=dead |archive-url=https://web.archive.org/web/20120209044315/http://www.ecs.org/html/aboutECS/ECS_exec_mgt_bios.htm |archive-date=2012-02-09 |access-date=2012-02-19 |work=ECS Official Website |publisher=Education Commission of the States |quote=John Hickenlooper, Chair}}</ref>
*[[Western Interstate Commission for Higher Education]]
*[[New England Board of Higher Education]]

===Energy===

* [[Regional Greenhouse Gas Initiative]] ([[Connecticut]], [[Delaware]], [[Maine]], [[Maryland]], [[Massachusetts]], [[New Hampshire]], [[New Jersey]], [[New York (state)|New York]], [[Rhode Island]], [[Vermont]], and [[Virginia]])<ref>{{Cite web|url=http://www.rggi.org/market/market_monitor|title=Welcome|website=www.rggi.org|publisher=RGGI, Inc.|access-date=2021-05-04|archive-date=2018-01-03|archive-url=https://web.archive.org/web/20180103023102/http://www.rggi.org/market/market_monitor|url-status=dead}}</ref><ref name="bacon">{{Cite web|url=https://www.baconsrebellion.com/wp/more-power-for-states-good-or-bad/|title=More Power for States: Good or Bad? &#124; Bacon's Rebellion|date=18 March 2019}}</ref>
*[[Northwest Power and Conservation Council]] ([[Oregon]], [[Washington (state)|Washington]], [[Montana]], and [[Idaho]]<ref>{{cite web |title=Northwest Power & Conservation Council |url=http://www.nwcouncil.org}}</ref>)
* [[Interstate Oil and Gas Compact Commission]]
* [[Southern States Energy Board|Southern States Energy Compact]] (18 states)
* Appalachian States Low-Level Radioactive Waste Compact (Delaware, Maryland, Pennsylvania, West Virginia)
* [[Central Interstate Low-Level Radioactive Waste Compact]] (Arkansas, Kansas, Louisiana, Oklahoma)
* Central Midwest Low-Level Radioactive Waste Compact (Illinois, Kentucky)
* Midwest Interstate Low-Level Radioactive Waste Compact (Indiana, Iowa, Minnesota, Missouri, Ohio, Wisconsin)
* Northeast Interstate Low-Level Radioactive Waste Management Compact (Atlantic Compact; Connecticut, New Jersey, South Carolina)
* Northwest Interstate Compact on Low-Level Radioactive Waste Management (Alaska, Hawaii, Idaho, Montana, Oregon, Utah, Washington, Wyoming) 
* Rocky Mountain Low-Level Radioactive Waste Compact 
* Southeast Interstate Low-Level Radioactive Waste Compact
* Southwestern Low-Level Radioactive Waste Disposal Compact
* Texas Low Level Radioactive Waste Disposal Compact
* Western Interstate Nuclear Compact (Alaska, Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, Wyoming)

===Other===
*[[Interstate Compact on the Placement of Children]] (all 50 states)
*Interstate Compact on Educational Opportunity for Military Children (all states, and the [[United States Department of Defense]] in an ex-officio, non-voting role)<ref>{{Cite web |title=The Military Interstate Compact |url=https://www.dodea.edu/education/partnership-and-resources/military-interstate-compact |archive-url=http://web.archive.org/web/20241206170248/https://www.dodea.edu/education/partnership-and-resources/military-interstate-compact |archive-date=2024-12-06 |access-date=2025-01-29 |website=DoDEA |language=en}}</ref><ref>{{Cite web |title=Background - MIC3 |url=https://mic3.net/background/ |access-date=2025-01-29 |website=mic3.net/ |language=en-US}}</ref><ref>{{Cite web |date=2024-07-12 |title=Interstate Compact on Educational Opportunity for Military Children – National Center for Interstate Compacts {{!}} The Council of State Governments |url=https://compacts.csg.org/compact/interstate-compact-on-educational-opportunity-for-military-children/ |access-date=2025-01-29 |language=en-US}}</ref>
*[[Interstate Commission for Adult Offender Supervision]] (all states, two territories, and Washington, D.C.)<ref>{{cite web|url=http://www.interstatecompact.org|title=ICAOS – Interstate Commission for Adult Offender Supervision|first=ICAOS -|last=Website}}</ref> 
*[[Driver License Compact]] (all states except [[Georgia (U.S. state)|Georgia]], [[Massachusetts]], [[Tennessee]], and [[Wisconsin]])
*[[Electronic Registration Information Center]] (32 states and [[Washington, D.C.]])
*[[Multistate Tax Commission]] (all states except Delaware, Nevada, and Virginia)
*Interstate Compact on Industrialized/Modular Buildings (Minnesota, New Jersey, North Dakota, Rhode Island)
*Interstate Insurance Product Regulation Compact (45 states and D.C.)
*Interstate Insurance Receivership Compact (Illinois, Michigan, Nebraska)

== Non-operating interstate compacts ==

=== With at least one state ===
*[[National Popular Vote Interstate Compact]], which will not take effect until additional states join the compact to send all their electors to the [[United States Electoral College|electoral college]] based on the results of the popular vote. Currently joined by 17 states and the District of Columbia, amounting to 209 (out of a minimum 270) Electoral College votes, as of 2025.

=== No longer active ===
*[[Northeast Interstate Dairy Compact]], cancelled in 2001 by an act of Congress
*[[Transportation Climate Initiative]],<ref name="bacon" /> a proposed compact among the same states as the Regional Greenhouse Gas Initiative
*[[Waterfront Commission of New York Harbor]] ([[New Jersey]] and [[New York (state)|New York]])<ref>{{cite web|url=http://www.waterfrontcommission.org|title=Waterfront Commission of New York Harbor (WCNYH)}}</ref> (Dissolved in 2023 after New Jersey withdrew from the pact)
=== Proposed ===
*[[Phase Out Corporate Giveaways Interstate Compact]], proposed compact that would commit signatory states to ending the [[economic development]] practice of providing targeted [[Subsidy|subsidies]], [[Tax abatement|tax abatements]] and other forms of financial [[Incentive|incentives]] to private companies
*Potomac Compact for Fair Representation, proposed compact to mutually establish independent [[Redistricting commission|redistricting commissions]] for congressional [[redistricting]], initially between Virginia and Maryland.<ref>{{Cite web |date=2016-02-11 |title=Groundbreaking Maryland Legislation Seeks to End Congressional Gerrymandering with Fair Representation |url=https://fairvote.org/groundbreaking_maryland_legislation_seeks_to_end_congressional_gerrymandering_with_fair_representation/ |access-date=2024-05-29 |website=FairVote |language=en}}</ref> 

== See also ==
{{Commons category|Interstate compacts of the United States}}
* [[American Association of State Highway and Transportation Officials]], [[United States Numbered Highway System]], and the [[United States Bicycle Route System]]
* [[Enhanced cooperation]], a similar system in the European Union
* [[Occupational licensing]], a more recent focus of newer interstate compacts
* [[Treaty]], an agreement between two or more international actors (usually sovereign states)

== References ==
{{Reflist|30em}}

== Works cited ==
* {{cite report|last1=Neale|first1=Thomas H.|last2=Nolan|first2=Andrew|title=The National Popular Vote (NPV) Initiative: Direct Election of the President by Interstate Compact|publisher=[[Congressional Research Service]]|date=October 28, 2019|url=https://crsreports.congress.gov/product/pdf/R/R43823/9|access-date=November 10, 2019}}

== External links ==

* [https://compacts.csg.org/database/ National Center for Interstate Compacts (NCIC) Database], [[Council of State Governments]]
{{Constitution of the United States}}

[[Category:Article One of the United States Constitution]]
[[Category:United States interstate agencies]]
[[Category:United States interstate compacts| ]]