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State Electricity Rates

Illinois Electricity Rate Changes: What Changed in 2026 and What's Next

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Published: September 30, 2026 | Last verified: September 30, 2026

Illinois is one of the few states where a real, documented rate change lands on October 1, 2026. Both of the state’s largest utilities reset the default price of the electricity itself (the “supply” part of your bill) for the fall and winter. Ameren Illinois customers in central and southern Illinois see a drop of about 8% from the summer price. ComEd customers in northern Illinois see a smaller drop of about 3%. Both prices are still high compared with two years ago, and neither change touches the delivery part of your bill.

Quick Summary

UtilityEffective DatePrevious RateNew RateChangeCustomer Impact
Ameren IllinoisOct. 1, 2026 (through May 2027)11.326¢/kWh (summer, first 800 kWh)10.441¢/kWh for the first 800 kWh; 8.262¢/kWh above 800 kWh−0.885¢/kWh (about −7.8%) on the first 800 kWhLower default supply price; applies to customers who buy supply from Ameren
ComEdOct. 1, 2026 (through May 2027)10.399¢/kWh (summer)10.103¢/kWh−0.296¢/kWh (about −2.8%)Lower default supply price; a separate monthly bill credit is also shrinking (see below)

What these figures are: each is the utility’s “price to compare,” the default supply price plus a transmission charge (and, for Ameren, a small supply cost adjustment). They are not your total bill and not the delivery charge.

What Is Changing on October 1, 2026?

Illinois utilities charge you two things: supply (the electricity itself) and delivery (the wires, poles and meters). Utilities do not mark up supply. They pass along what they pay.

  • Ameren Illinois uses one price for summer (June–September) and another for the rest of the year. The October 2026–May 2027 price to compare is 10.441¢ per kWh for the first 800 kWh you use in a month and 8.262¢ per kWh for anything above that, according to the Citizens Utility Board (CUB), which reported Ameren’s confirmation on September 28, 2026. The Illinois Commerce Commission’s Plug In Illinois site lists the summer figure at 11.326¢ for the first 800 kWh. CUB notes the new price is still about 24% higher than last October’s 8.402¢.
  • ComEd’s new price to compare for October 2026–May 2027 is 10.103¢ per kWh, per CUB. That is about 53% above the price two years ago, CUB says.

Both changes are driven by the wholesale cost of electricity and “capacity” (the price of having power plants available). CUB points to the capacity auctions run by MISO (Ameren’s grid operator) and PJM (ComEd’s) and to rising demand, including from data centers.

How Much Could Your Electric Bill Change?

Neither utility has published a single “typical bill” estimate that we could verify, so here is an illustration using the published prices. It covers supply only, not delivery, taxes or fees.

  • Ameren, 700 kWh in a month (all within the first 800 kWh): 700 × 11.326¢ = $79.28 at the summer price versus 700 × 10.441¢ = $73.09 at the new price. That is about $6.19 less per month.
  • ComEd, 700 kWh in a month: 700 × 10.399¢ = $72.79 versus 700 × 10.103¢ = $70.72, about $2.07 less.

ComEd credit caveat. Most ComEd customers also get a monthly credit called the Carbon-Free Energy Resource Adjustment. CUB reports it ranged from about 1.6¢ per kWh in September to about 0.115¢ per kWh in October, and that it adjusts every month. If those figures hold, a 700 kWh customer would lose roughly $10 of credit (700 × about 1.485¢), more than the $2.07 saved on the lower price. The credit is scheduled to end in June 2027. Watch the credit line on your own bill.

Which Customers Are Affected?

  • Affected: residential customers who take default supply from Ameren Illinois or ComEd.
  • Not directly affected: customers who buy supply from an alternative retail supplier or through a city’s municipal aggregation program. Their supply price is whatever their contract says. CUB reports that most municipal aggregation deals it reviewed in Ameren territory cost more than the utility’s price.
  • Not covered here: MidAmerican Energy customers in the Quad Cities area and Illinois’s municipal and co-op utilities.
  • Choice: Illinois customers can shop for supply. The utility keeps delivering power either way.

What This Means for Homeowners With Solar

  • Net metering rules depend on when your system was connected. Per Illinois Shines and DSIRE, systems interconnected before January 1, 2025 that did not take the one-time distributed generation rebate keep full retail net metering. Systems connected on or after January 1, 2025 are on a net billing structure, where exports are credited using supply-related components (energy, capacity and transmission) rather than the full retail rate.
  • Lower supply prices matter more to new-rule systems than you might expect. Because exports are credited on supply components, a lower default supply price does not by itself mean a bigger export credit, and the credit is not simply equal to the price to compare. Check your utility’s tariff or your bill for how your credits are calculated.
  • Self-consumption: under supply-only crediting, using your own solar power in the house avoids the full retail rate, including delivery, while exporting earns only the supply value. That gap is the main reason batteries are discussed for newer systems.
  • Rebates: ComEd and Ameren offer a distributed generation (smart inverter) rebate and a storage rebate, per Illinois Shines. Confirm current amounts and requirements with your utility before buying.
  • Payback: the supply price moved by less than 1 cent, so this change alone should not alter a payback estimate much.

What Homeowners Should Check on Their Electric Bill

  1. Who supplies your electricity. Look for “Electric Supply” charges from your utility or from a third party.
  2. Your supply rate versus the price to compare. If a supplier’s rate is above 10.441¢ (Ameren, first 800 kWh) or 10.103¢ (ComEd), you may be paying more than the default.
  3. Contract end dates on any fixed-rate supplier plan.
  4. The ComEd credit line (Carbon-Free Energy Resource Adjustment).
  5. Delivery charges, which are separate and not part of this change.

What Happens Next

  • Ameren delivery request: CUB says Ameren is seeking a $65 million increase to delivery rates. That case is pending, and we did not find a decision date.
  • ComEd credit: scheduled to end in June 2027, per CUB.
  • Energy assistance: CUB notes some income-eligible households can apply for LIHEAP starting October 1, 2026, and all eligible households from November 1.
  • Summer 2027 prices have not been published.

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