If you buy electricity in Illinois and have never chosen a supplier, you pay your utility's default supply rate, called the Price to Compare. As of June 2026, that rate is 10.399 cents per kilowatt-hour in ComEd territory and 11.326 cents in Ameren Illinois territory. Those two numbers are the benchmark every competitive offer has to beat.
The Price to Compare is also the most misunderstood number on an Illinois electric bill. It is not your total rate, it changes on a schedule, and for a large share of Illinois residents it isn't even the rate they're actually paying. This guide explains what the Price to Compare is, what ComEd's and Ameren's current figures are, how to use the number when you shop, and the one Illinois wrinkle that most comparison sites skip.
The short answer
- The Price to Compare (PTC) is your utility's default electricity supply rate, the per-kilowatt-hour price you pay for the electricity itself if you never pick a competitive supplier. It is the number a competitive offer has to beat to save you money.
- ComEd's Price to Compare is 10.399¢/kWh, a flat supply rate effective June 1, 2026.
- Ameren Illinois's Price to Compare is 11.326¢/kWh for the first 800 kWh, the summer rate effective June 1 through September 30, 2026. Ameren's PTC is tiered by usage and changes by season.
- The PTC covers supply only. It is not your total bill rate. Delivery charges are separate and stay with your utility no matter who supplies your power.
- If your town runs a municipal aggregation program, the rate on your bill may be an aggregation rate rather than the PTC, and that is the number an offer has to beat instead.
What the Price to Compare actually is
Illinois opened its electricity market to competition under the 1997 Customer Choice law. That means you can choose who supplies your power. Your utility, ComEd or Ameren Illinois, still owns the wires, reads the meter, and restores service after a storm, but the electricity itself can come from a competitive supplier, called an Alternative Retail Electric Supplier (ARES).
If you never make that choice, you stay on your utility's default supply, and the rate you pay for it is the Price to Compare. The name is literal: it is the number you compare a competitive offer against. If a supplier quotes a rate below your PTC, it beats the default. If it quotes a rate above, it doesn't.
The most important thing to understand about the PTC is what it does not include. Your electric bill has two parts. The delivery charge covers the poles, wires, and meter, and it stays with your utility regardless of who supplies your power. The supply charge covers the electricity itself, and that is the only part you can shop. The Price to Compare is a supply rate. Switching suppliers, or being on a town aggregation rate, changes the supply charge and nothing else.
This is why the PTC looks low next to the rate you think you pay. The all-in average residential rate, which includes both supply and delivery, runs higher. According to the U.S. Energy Information Administration, the 2024 average residential rate was 15.22¢/kWh in ComEd territory and 15.26¢/kWh in Ameren territory. Those figures bundle delivery into the number; the Price to Compare does not. Comparing a supplier's supply-only rate against your all-in average is the most common mistake Illinois shoppers make, and it makes competitive offers look better than they are. Compare supply to supply.
ComEd's Price to Compare right now
ComEd's Price to Compare is 10.399¢/kWh, a flat supply rate effective June 1, 2026. ComEd serves about 2.9 million residential customers across northern Illinois, including the Chicago metro.
Unlike some utilities, ComEd's residential PTC is a single flat number rather than a tiered or seasonal rate. It is built from three components:
| Component | Rate |
|---|---|
| Electric supply charge | 8.677¢ |
| Transmission services charge | 1.722¢ |
| Renewable energy adjustment | ~0.172¢ |
| Total Price to Compare | 10.399¢ |
The supply charge is the cost of the electricity itself. The transmission charge covers moving power across high-voltage lines into ComEd's territory. The renewable energy adjustment reflects Illinois's clean-energy procurement requirements. Added together, they are the supply benchmark a competitive ARES offer has to beat.
A full breakdown, with the official source and the delivery-versus-supply distinction laid out, lives on our ComEd electricity rates page. If you're in the Chicago area specifically, our Chicago electricity guide covers the same benchmark at the city level.
Ameren Illinois's Price to Compare right now
Ameren Illinois's Price to Compare is 11.326¢/kWh for the first 800 kWh, the summer rate effective June 1 through September 30, 2026. Ameren serves about 520,000 residential customers across central and southern Illinois.
Ameren's PTC is more complicated than ComEd's, and the complexity is real rather than a quirk worth glossing over. Two things make it harder to pin down:
- It is tiered by usage. The 11.326¢ figure is the rate for the first 800 kilowatt-hours in a billing period. Usage beyond that tier is priced differently.
- It changes by season. The figure above is the summer rate. The non-summer supply charge is lower. The PTC resets on a seasonal schedule rather than holding flat all year.
Many comparison sites flatten Ameren's PTC into a single year-round number. That is convenient, but it's wrong often enough to matter, because the rate you should be comparing against depends on your usage level and the time of year. Before you judge a competitive offer in Ameren territory, confirm the current PTC for your usage and your season. The current figure and the tier-and-season structure are kept up to date on our Ameren Illinois electricity rates page, and our Peoria electricity guide applies the same benchmark for one of Ameren's larger metros.
How to actually use the Price to Compare
Knowing the number is the easy part. Using it well is where most of the savings, and most of the mistakes, live.
Compare the offer's supply rate to your PTC
A competitive offer saves you money only if its supply rate is below your Price to Compare. In ComEd territory that means beating 10.399¢/kWh. In Ameren territory it means beating the current tiered, seasonal PTC for your usage, which is 11.326¢/kWh for the first 800 kWh this summer. Any clean fixed offer below your benchmark cuts your supply charge; anything above it costs you more than doing nothing. We rank the offers that clear that bar, by utility, on our best Illinois electricity plans page.
Watch the term, not just the headline rate
A rate below the PTC today is only worth something if it holds. Many low introductory rates are short teasers that expire after a few months and roll onto a variable rate well above the PTC. A fixed-rate plan with a stated term tells you exactly how long the rate lasts. A variable rate can move every month. The headline number means little without the term attached to it.
Read the fees
The supply rate is not the whole cost. A monthly service fee, an early-termination fee, or a minimum-usage charge can erase the savings from a rate that looked lower than the PTC. A plan at 9.9¢ with a $9.95 monthly fee can cost more than the default for a modest household. Read the contract summary before the headline rate convinces you.
Calculate the effective rate
The number that matters is the effective rate: what you actually pay per kWh once fees, credits, and term are folded in, at your usage. A plan built around a bill credit at 1,000 kWh a month is a different deal for a household that uses 600 or 1,800. Run the math at your own usage rather than the advertised usage, then compare that effective rate to your PTC. If it doesn't beat the benchmark at your usage, it isn't a better deal for you.
The aggregation wrinkle
Here is the part most comparison sites skip, and it changes the question entirely for a large share of Illinois residents.
Hundreds of Illinois communities run municipal aggregation programs. Under aggregation, a city or village negotiates a single electricity supply rate for its residents and enrolls everyone automatically, on an opt-out basis. If your town is one of them, the supply rate on your bill is your aggregation rate, not the utility's Price to Compare. And that aggregation rate, not the PTC, is the number a competitive offer actually has to beat for you.
This matters because the standard advice, "switch off the utility default," assumes you're on the default. If you're aggregated, you're not. Aggregation rates are sometimes better than the Price to Compare and sometimes worse, depending on when your town locked its contract and where wholesale prices have moved since. So the honest first step in much of Illinois isn't shopping against the PTC; it's checking your bill to see whether you're on the aggregation rate or the utility rate, then comparing from there.
The wrinkle cuts the other way too. Chicago, for instance, ran one of the largest municipal aggregation programs in the country, then suspended it in 2015, so most Chicago residents are now on the ComEd Price to Compare rather than an aggregation rate. The only way to know which rate applies to you is to look. Our guide to Illinois municipal aggregation explains how to tell whether your town runs a program, how to opt out for free, and how to compare your aggregation rate against both the PTC and a competitive offer.
Where to find the official current numbers
The Price to Compare is a current value that changes, not a permanent fact. ComEd's resets on its own schedule; Ameren's changes by season and tier. The figures in this guide are accurate as of June 2026, but the only number that matters when you shop is the one in effect at that moment.
Two reliable places to confirm it:
- Plug In Illinois (plugin.illinois.gov), the official site run by the Illinois Commerce Commission (ICC), publishes each utility's current Price to Compare and lists certified ARES offers you can compare against it.
- Your utility's rate page. We keep the current ComEd and Ameren figures, their effective dates, and their component breakdowns on our Illinois electricity hub and the two utility pages linked above, sourced from Plug In Illinois.
Whichever source you use, confirm the effective date. A Price to Compare from last season is the wrong benchmark for a decision you're making today.
FAQ
What is the Price to Compare in Illinois?
The Price to Compare (PTC) is your utility's default electricity supply rate, the per-kilowatt-hour price you pay for the electricity itself if you don't choose a competitive supplier. It is the benchmark a competitive offer has to beat to save you money. As of June 2026 it is 10.399¢/kWh in ComEd territory and 11.326¢/kWh (summer, first 800 kWh) in Ameren Illinois territory. The PTC covers supply only, not delivery.
What is ComEd's Price to Compare?
ComEd's Price to Compare is 10.399¢/kWh, a flat supply rate effective June 1, 2026. It is made up of an 8.677¢ electric supply charge, a 1.722¢ transmission services charge, and a renewable energy adjustment of about 0.172¢. Any competitive supplier rate below 10.399¢ beats the ComEd default.
What is Ameren's Price to Compare?
Ameren Illinois's Price to Compare is 11.326¢/kWh for the first 800 kWh, the summer rate effective June 1 through September 30, 2026. Ameren's PTC is tiered by usage and changes by season, so the non-summer rate is lower and usage above the first tier is priced differently. Confirm the current figure for your usage and the time of year before comparing offers.
Is the Price to Compare the same as my total electricity rate?
No. The Price to Compare is a supply rate only. Your total bill also includes delivery charges, the cost of the poles, wires, and meter, which stay with your utility no matter who supplies your power. The all-in average residential rate, which includes both supply and delivery, was 15.22¢/kWh in ComEd territory and 15.26¢/kWh in Ameren territory in 2024, according to the EIA. Compare a supplier's supply rate against the PTC, not against your all-in rate.
How often does the Price to Compare change?
It changes on a schedule that varies by utility. ComEd's flat residential Price to Compare resets periodically; the current figure is effective June 1, 2026. Ameren's PTC is tiered by usage and resets seasonally; the 11.326¢ summer rate runs June 1 through September 30, 2026, and the non-summer rate is lower. Because the PTC is a current value that changes, always confirm the rate in effect on the day you shop, through Plug In Illinois or your utility's rate page.