analysis6 min read

Your Illinois Electric Rate Drops October 1 — Why Your Bill Won't Drop as Much

Ryan Cook•July 27, 2026

Your electric rate is about to get cheaper. Your bill is going to disappoint you anyway.

Here's the setup. Illinois utilities run two supply prices a year. The expensive one covers June 1 through September 30. The cheaper one covers October 1 through May 31. Right now Ameren Illinois is charging 11.326 cents per kWh on the first 800 kWh, and ComEd is charging 10.399 cents. Both of those die on September 30.

Last year the drop was dramatic. Ameren's price went from 12.18 cents to 8.402 cents on October 1, 2025. The Citizens Utility Board put out an alert the same day calling it a 31 percent cut. If you were an Ameren customer, that was the single biggest piece of good news your bill got all year.

Which raises the fair question I've been getting on the phone all month: is that happening again, and how much of it lands in my pocket?

What actually changes on October 1

Only supply. That's the whole story in two words.

Your bill has two halves. Supply is the electricity itself — the commodity, bought on wholesale markets. Delivery is everything that moves it to your house: poles, wires, the meter, the fixed monthly customer charge, the grid programs riding along on your bill.

The seasonal reset touches supply and nothing else. Delivery keeps doing whatever delivery was already doing.

That distinction is the entire reason people feel lied to in October. They read "rates drop 31 percent," they do the arithmetic on their $220 bill, they expect to see something near $150, and they get $195. Nobody lied. CUB's own framing is that supply runs about half to two-thirds of a typical bill. Cut two-thirds of something by 31 percent and you've cut the whole thing by about 20 percent. Cut half of it and you're closer to 15.

That's still real money. It's just not the number in the headline.

What we know about the October 2026 rate

Less than you'd hope, and I'd rather say that than guess.

The non-summer price for October 2026 through May 2027 has not been published. It normally posts on the ICC's Plug In Illinois site in the weeks before October 1. What I can tell you is the shape: the seasonal pattern is durable, the non-summer price has been meaningfully below the summer price every year I've been doing this, and the summer figure it's replacing is 11.326 cents.

What I can't tell you is the number. Supply prices get rebuilt from wholesale procurement results each period, and there's a monthly supply cost adjustment that nudges the figure around. Anybody publishing a confident October 2026 rate in July is reading tea leaves.

If you want the current verified figures rather than a forecast, I keep the Ameren rate breakdown and the ComEd rate breakdown updated as the official numbers land.

The half of the bill that doesn't care what season it is

Here's what bothers me about how this gets covered every autumn. The seasonal drop gets a news cycle. The thing quietly moving the other direction doesn't.

Delivery charges change through rate cases at the Illinois Commerce Commission. Right now Ameren Illinois has roughly $65.3 million in requested increases pending and ComEd has roughly $234.3 million, with decisions expected in November and December of this year. When CUB flagged that 31 percent supply drop back in October 2025, the same post pointed out that Ameren was simultaneously trying to raise delivery charges by $60.6 million.

Underneath that sits the pressure I've written about before — data center demand reshaping what capacity costs and the MISO capacity market driving Ameren bills upward. Those forces don't take the winter off.

The honest framing is this: October gives you a seasonal discount on the half of your bill that moves with the weather, while the half that moves with regulatory decisions keeps grinding upward. You get relief. You don't get a trend reversal.

If someone knocks between now and September 30

Two things worth having in your pocket.

First, the supplier pitch. Late summer is prime season for someone offering to beat your rate, and the math they'll show you is measured against the 11.326 cent summer price. That price is expiring on its own. A rate that beats summer supply can easily lose to the October price you'd have gotten by doing nothing. CUB has said flatly that the utility is likely your best bet for supply, and that Illinois consumers have lost over $2 billion to alternative suppliers in the past decade. If you're comparing an offer, compare it against the rate that'll be live during the contract, not the one about to expire.

Second, the solar version of the same question. Solar offsets supply — the exact half of the bill that's about to get cheaper. That's worth being clear-eyed about, because it means a solar quote run against summer rates flatters itself a little. When I put numbers in front of someone in July, I'd rather show the annual average than the summer peak, even though the summer peak sells better.

What a lease actually changes is the volatility. Instead of a supply price that resets twice a year on wholesale results, you're at a known per-kWh price — as low as 10 cents per kWh on average, depending on the home and the system. Whether that beats riding utility supply is a real question with a real answer, and it's different for a house in Belleville than one in Peoria. I walk through the tradeoff in detail in leasing versus buying panels in Illinois, and the June rate increase post has the summer figures if you want the mirror image of this one.

What I'd actually do

Nothing dramatic. Three things.

Don't sign a supply contract in August or September against a rate that expires September 30. Check your October bill against your September bill rather than against last October's, so you're measuring the reset and not a year of delivery increases. And if you've been running solar numbers on summer rates, re-run them on the annual average before you decide anything — an estimate built on the highest four months of the year isn't an estimate you can plan around.

If you want your actual numbers rather than the statewide averages, run your bill through the savings calculator or call me at (618) 217-2001. I'd rather show you a smaller honest number than a bigger one you'd resent in October.

These are estimates based on current published rates and my read of the seasonal pattern — not promises. The October 2026 supply price hasn't been filed yet, and when it lands I'll update this post with the real figure.

Frequently Asked Questions

Your supply rate almost certainly goes down. Your total bill goes down by less. Illinois utilities charge a higher supply price June 1 through September 30 and a lower one October 1 through May 31. Ameren Illinois is charging 11.326 cents per kWh this summer on the first 800 kWh, and ComEd is charging 10.399 cents. Both of those expire September 30. For scale, last year Ameren's price fell from 12.18 cents to 8.402 cents on October 1, 2025 — a 31 percent drop that the Citizens Utility Board flagged the day it happened. But supply is only one piece of your bill. CUB puts it at roughly half to two-thirds. The delivery side does not reset with the season, so a 31 percent cut to supply is nowhere near a 31 percent cut to what you actually pay. Expect real relief, just smaller than the headline.

It has not been published yet, and I would be careful with anyone who tells you a specific number today. As of late July 2026, the only rate officially in effect is the summer price of 11.326 cents per kWh, good June 1 through September 30, 2026. The non-summer price that replaces it normally posts in the weeks before October 1 on the Illinois Commerce Commission's Plug In Illinois site. The seasonal pattern says it should land lower than the summer price — last year's non-summer rate was 8.402 cents per kWh on the first 800 kWh and 7.483 cents above that. But a pattern is not a filing. Supply prices are rebuilt from wholesale market results each period, and a monthly supply cost adjustment moves the figure a little either way. Treat any October number you see right now as an estimate, not a rate.

Because the part that went down is not the part that has been growing. Your bill splits into supply, which is the electricity itself, and delivery, which is the poles, wires, meters and fixed charges that get it to you. Only supply swings with the season. Delivery changes through rate cases at the Illinois Commerce Commission, and those have been moving one direction. Ameren Illinois has about 65.3 million dollars in requested increases pending, and ComEd about 234.3 million, with ICC decisions expected in November and December 2026. There is also a fixed customer charge every month that no rate change touches. So you can get a genuine seasonal cut on supply and still open a bill that looks stubbornly similar to last year's, because the growing half of the bill quietly moved up while the seasonal half moved down.

I would slow down on that one, and this is not my lane to sell. The Citizens Utility Board has been blunt about it: Illinois consumers have lost more than two billion dollars to alternative retail suppliers over the past decade, and CUB has said outright that the utility is likely your best bet for supply. The specific trap around October is timing. A supplier can quote you a rate that looks great against the summer price of 11.326 cents, get your signature in August or September, and then that deal looks a lot worse on October 1 when the utility price resets down on its own. Always compare an offer against the rate that will be in effect during your contract, not the one expiring. Check the contract length, the cancellation fee, and whether the rate is fixed or variable.

It changes which swings you are exposed to, and that is the honest version. Solar offsets the supply side of your bill — the part that jumps every June and eases every October. It does not erase delivery charges or the fixed monthly customer charge, and any solar company telling you your bill goes to zero is not being straight with you. What a lease does add is price predictability. Instead of a supply rate that resets twice a year on wholesale market results, you have a known per-kWh price, as low as 10 cents per kWh on average depending on the home and the system. Whether that beats staying fully on utility supply depends on your roof, your usage and your territory. These are estimates, not promises, and the only way to know your number is to run your actual bill.