Illinois Municipal Electric Aggregation

A city, village or county asks its voters to approve aggregation, then negotiates a supply contract through a bid. Residents on the utility’s default supply are enrolled unless they opt out. ComEd or Ameren still delivers the power and usually still sends the bill; the supply price is what changes.

“Opt-out requires the voters of a municipality or county to pass a referendum that automatically combines the electric load for residential and eligible small businesses for purchasing purposes except for those customers who actively choose not to participate in the municipality's or county's purchase program.”— Municipal Aggregation, Plug In Illinois (Illinois Commerce Commission)

• Opting out. “The chosen supplier will send opt-out notices to all residents and eligible small businesses within the municipality or county. You will need to fill out and return the opt-out notice in order to be excluded from the aggregation program.”
• Leaving later. “Suppliers are prohibited from applying early termination fees or penalties to residential and small commercial retail customers who terminate their contracts and switch to a different supplier or go back to the utility's service.”
• If you already buy from a supplier. “If you are enrolled with a supplier or the utility's residential real-time program at the time the opt-out notices are being sent out, you will likely not be included in your municipality's or county's aggregation program.”
• Your bill. “In most cases, you will continue to receive one bill from the utility that will contain both the utility's delivery charges and the chosen supplier's electric supply charges billed at the negotiated rate.”
• Contract length. “The Illinois aggregation programs currently in effect range from one year to three years in length.”
• Electric heat. “Electric space heating rate customers may not save money.”
• Outages. “You continue to call your local utility company (Ameren Illinois or ComEd).”

Quotes from Municipal Aggregation, Plug In Illinois (Illinois Commerce Commission). The law is Section 1-92 of the Illinois Power Agency Act (20 ILCS 3855/1-92).

The price to compare is the utility’s own supply price, which residents pay if they don’t buy from a supplier. Aggregation rates are fixed for the contract, while the price to compare resets several times a year, so a program can be cheaper in one season and more expensive in the next.

Prices to compare from Plug In Illinois (ICC), effective October 1, 2026 to May 31, 2027; the previous price applied June 1, 2026 to September 30, 2026. * Ameren’s price is 10.441¢ for the first 800 kWh a month and 8.262¢ after that.

Rates are residential supply prices from the ICC list, checked November 2, 2026. “vs. default” compares each fixed rate with its utility’s current price to compare.

26 programs’ contracts end by May 2027. When a contract ends, the community either signs a new one or the program stops.

5 suppliers serve all 418 active programs. Homefield Energy has the most, with 188.

313 Illinois communities had an aggregation program that has since ended, and 21 passed a referendum but haven’t chosen a supplier.