MISO website

Map of Middle America

MISO operates the transmission system and a centrally dispatched market in portions of 15 states in the Midwest and the South, extending from Michigan and Indiana to Montana and from the Canadian border to the southern extremes of Louisiana and Mississippi. The system is operated from three control centers: Carmel, Indiana; Eagan, Minnesota; and Little Rock, Arkansas. MISO also serves as the reliability coordinator for additional systems outside of its market area, primarily to the north and northwest of the market footprint.

MISO was not a power pool before organizing as an ISO in December 2001. It began market operations in April 2005. In January 2009, MISO started operating an ancillary services market and combined its 24 separate balancing areas into a single balancing area. In 2013, the RTO began operations in the MISO South region, including the utility footprints of Entergy, Cleco, and South Mississippi Electric Power Association, among others, in parts of Arkansas, Mississippi, Louisiana, and Texas.

List of Orders

Click on the categories below to view additional information.

Docket No. Date Issued Company Title
ER24-2797-001 06/26/25 Midcontinent Independent System Operator Order Addressing Arguments Raised on Rehearing

ER20-1298-006

04/17/25 Midcontinent Independent System Operator, Inc.

Letter Order Accepting Proposed Tariff Revisions

ER24-1586-001 03/20/25 Midcontinent Independent System Operator, Inc. Montana Dakota (waiver request) Rehearing ER24-1586-001
ER22-1640-003 01/16/25 Midcontinent Independent System Operator, Inc. Advisory

Order On Compliance Filing

Docket No. Date Issued Company Title

ER24-165-000

07/25/24 Midcontinent Independent System Operator, Inc 

Order on Compliance Filing

ER23-2977-000  06/27/24 Midcontinent Independent System Operator, Inc  Order Accepting Tariff Revisions 
ER24-340-001 04/25/24 Midcontinent Independent System Operator, Inc. Order Addressing Arguments Raised on Rehearing.
ER24-1225-000 04/25/24 California Independent System Operator Corporation. Order Accepting Tariff Revisions
Docket No. Date Issued Company Title
ER22-2363-000 06/15/23 Midcontinent Independent System Operator, Inc. Order on Compliance Filing
EL22-59-001 04/20/23 Tenaska Clear Creek Wind, LLC v. Southwest Power Pool, Inc.
Midcontinent Independent System Operator, Inc.
Associated Electric Cooperative, Inc.
Tennessee Valley Authority
Order Addressing Arguments Raised on Rehearing
ER19-776-002 02/16/23 Midcontinent Independent System Operator, Inc. Opinion No. 580-A; Order Addressing Arguments Raised On Rehearing
ER22-495-002 02/16/23 Midcontinent Independent System Operator, Inc. Order Addressing Arguments Raised on Rehearing and on Compliance
Docket No. Date Issued Company Title
ER22-477-002 12/15/22 Midcontinent Independent System Operator, Inc. Order Addressing Arguments Raised on Rehearing
ER22-477-002 12/15/22 Midcontinent Independent System Operator, Inc. Order Addressing Arguments Raised on Rehearing
EL15-70-003 12/15/22 Public Citizen, Inc. v. Midcontinent Independent System Operator, Inc.  Order Granting Motion
EL15-70-003 06/16/22 Public Citizen, Inc. v. Midcontinent Independent System Operator, Inc. Order on Remand, Establishing Paper Hearing Procedures, and Directing Staff Report and Briefing
ER22-461-000 01/20/22 Midcontinent Independent System Operator, Inc. Order on Waiver Requests and Tariff Revisions
Docket No. Date Issued Company Title
ER21-2348-000  09/23/21 Midcontinent Independent System Operator, Inc.  Letter Order Approving Uncontested Settlement
ER20-2322-000 06/17/21 Midcontinent Independent System Operator, Inc. Advisory 1 of 1 Order On Agreements
ER20-2352-000 06/17/21 Midcontinent Independent System Operator, Inc. Advisory 1 of 1 Order Rejecting Agreements
ER20-2364-000 06/17/21 Midcontinent Independent System Operator, Inc. Advisory 1 of 1 Order Conditionally Accepting Agreements Subject to Further Compliance Filing
ER21-834-001 05/20/21 Midcontinent Independent System Operator, Inc.  Order Accepting Unexecuted Facilities Service Agreement
ER21-836-001 05/20/21 Midcontinent Independent System Operator, Inc.  Order Accepting Unexecuted Facilities Service Agreement
ER21-837-001 05/20/21 Midcontinent Independent System Operator, Inc.  Order Accepting Unexecuted Facilities Service Agreement
ER20-2436-000, ER20-2437-000, ER20-2437-001 04/15/21 Midcontinent Independent System Operator, Inc. Order Conditionally Accepting Agreements
EL17-89-000 04/15/21 American Electric Power Service Corporation v. Midcontinent Independent System Operator, Inc. and Southwest Power Pool, Inc. Further Order on Complaints Following Briefing and Technical Conference
ER20-1892-000 03/18/21 Midcontinent Independent System Operator, Inc. Order Granting Waiver Request
ER21-679-000 03/18/21 Midcontinent Independent System Operator, Inc. Order Accepting Tariff Revisions, Subject to Condition
ER21-722-000 02/18/21 Midcontinent Independent System Operator, Inc. Order Accepting Unexecuted Facilities Service Agreement
ER21-721-000 02/18/21 Midcontinent Independent System Operator, Inc. Order Accepting Unexecuted Facilities Service Agreement
ER21-720-000 02/18/21 Midcontinent Independent System Operator, Inc Order Accepting Unexecuted Facilities Service Agreement
ER20-598-002 02/18/21 Midcontinent Independent System Operator, Inc. Letter Order Approving Uncontested Settlement

This page was last updated on June 26, 2025