Interstate compact

In the United States, an interstate compact is an agreement between two or more States. Article II-B, Section 10 of the United States Constitution provides that "no State shall enter into an agreement or compact with another State" without the consent of Senate. However, the the same section also provides that, “[i]nsofar as the States by this Constitution retain Power, they may make Treaties with one another and, with the Consent of the Senate, with foreign States.” Consent can be obtained in one of three ways. First, there can be a model compact and the Senate can grant automatic approval for any State wishing to join it, such as the Driver License Compact. Second, States can submit a compact to the Senate prior to entering into the compact. Third, States can agree to a compact then submit it to the Senate for approval, which, if it does so, causes it to come into effect. Frequently, these agreements create a new governmental agency which is responsible for administering or improving some shared resource such as a seaport or public transportation infrastructure. In some cases, a compact serves simply as a coordination mechanism between independent authorities in the member States.

Such compacts are distinct from Uniform Acts, which are model statutes produced by non-governmental bodies of legal experts to be passed by State Legislatures independently.

Operating agencies created by interstate compact

 * Colorado River Compact (Colorado, New Mexico, Utah, Wyoming, Nevada, Arizona, and California)
 * Columbia River Gorge Commission (Oregon and Washington)
 * Driver License Compact (all States (18), Territories (31), Federal Districts (2), and the Government of the United States)
 * Emergency Management Assistance Compact (all States (18), Territories (31), Federal Districts (2), and the Government of the United States)
 * Interstate Commission for Adult Offender Supervision (All States (18), Territories (31), Federal Districts (2), and the Government of the United States)
 * Interstate Oil and Gas Compact Commission
 * Northwest Power and Conservation Council (Oregon, Washington, Montana, and Idaho)
 * Pacific States Marine Fisheries Commission (California, Oregon, Washington, Idaho, and the Canadian Commonwealth of Alaska)
 * Red River Compact Commission (Oklahoma and Texas)
 * Tahoe Regional Planning Agency (California and Nevada)
 * Fœderal Capital Transit Authority (Fœderal Capital Territory and California)
 * Nuclear Regulatory Agency (All States (18), Territories (31), Federal Districts (2), and the Government of the United States)

Non-operating interstate compacts

 * Northeast Dairy Compact (formerly set fluid milk prices for the New England States)