The chart above is the reason this page can answer the question instead of guessing at it. It is ComEd's residential Price to Compare, the posted supply rate, for every month the Illinois Commerce Commission has published since January 2017. Two resets on that chart account for most of what people are feeling: June 2025, when the rate went from 6.552 to 10.028 cents per kWh, and June 2026, when it went from 9.660 to 10.399. This page goes through what those numbers are, what sits inside them, what moved on the delivery side at the same time, and what it all came to on a real ComEd bill we reconciled to the cent.
Everything here is a posted or filed figure or a reconciled bill. Nothing is a forecast. The page covers ComEd, whose record we hold in full; Ameren Illinois is posted on the same ICC publication but is not charted or discussed here.
The supply rate did most of it, in two steps
ComEd's supply rate is not set by ComEd. It is the cost of energy and capacity bought under a state procurement plan, passed through with no markup under the filed Rider PE, and posted by the ICC each month as the Price to Compare. It resets at the procurement boundaries in June and October, with small drifts in between. Here is the record for the last three summers, straight from the posting:
| posted month |
Price to Compare, cents per kWh |
change at the reset |
| June 2024 |
6.900 |
|
| May 2025 |
6.552 |
|
| June 2025 |
10.028 |
up 3.476 cents, about 53 percent |
| October 2025 |
9.689 |
down 0.339 |
| January 2026 |
9.660 |
|
| May 2026 |
9.660 |
|
| June 2026 |
10.399 |
up 0.739 cents, about 7.7 percent |
| August 2026 |
10.399 |
|
June 2025 is the step. In one reset the posted rate rose by more than half, and it has stayed within a cent of that level since. June 2026 added another 0.739 on top. From June 2024 to June 2026 the posted supply rate rose 3.499 cents per kWh, about 51 percent.
On a home using 1,518 kWh in a month, the reference bill on this site, the June 2024 to June 2026 difference on the supply and transmission lines alone is 3.499 cents times 1,518 kWh, which is $53.11 a month. That is arithmetic on two posted figures and one measured kWh, not a projection of anyone's bill.
What is inside the number that rose
The Price to Compare bundles two things a supply rate has to cover: the energy itself, and the generating capacity that has to stand ready for the region's peak hours. ComEd's filed tariff lists both among the "component services" it procures, and it is the capacity piece that explains why the step was so large and why it has not gone back down.
Capacity is priced by PJM, the regional grid operator, for each planning year that runs June through the following May, and ComEd publishes the resulting Monthly Capacity Charge with the ICC as Informational Sheet No. 4. That published charge appears as its own line for customers on Hourly Pricing and is folded invisibly into the Price to Compare for everyone else. The periods on file:
| billing months |
published Monthly Capacity Charge, dollars per kW-month |
| June to August 2025 |
8.33100 |
| September to December 2025 |
8.31935 |
| January to May 2026 |
8.32925 |
| June 2026 to May 2027 |
10.11236 |
The June 2026 step in that table is about 21 percent, and it lands on the same date as the June 2026 Price to Compare reset. Both figures are set for a planning year at a time, which is why the increases arrive in June and hold rather than drifting month to month.
The Purchased Electricity Adjustment is the small monthly line that trues the posted rate up or down against what the energy actually cost. It is posted alongside the Price to Compare, and on the reference bill it was 0.230 cents per kWh for June 2026, matching the posting. It moves every month and it is why two bills on the same Price to Compare can differ by a few dollars.
The delivery side is on a filed schedule of its own
The other half of the bill is delivery, ComEd's regulated charge for the wires, and it does not wait for June. Delivery rates are set by ICC order. The current sheets are filed under Docket No. 24-0378, a multi-year rate plan, and they print a column for each of 2025, 2026 and 2027, each followed by "& ADJ" for the adjustment factors that turn the printed figure into the rate a bill applies. For the residential class the 2026 column is higher than the 2025 column on both the Customer Charge and the Distribution Facilities Charge, and the 2027 column is already on file.
What that produced on an actual bill: the reference home's May 1 to June 2, 2026 bill carried a Customer Charge of $15.50 and a Distribution Facilities Charge of 6.333 cents per kWh, which came to $96.13 on 1,518 kWh. The Distribution Facilities Charge reconciled to the filed 2026 rate and its adjustment factors to the cent. The Customer Charge is checked against the bill rather than the tariff: the filed $13.26 with its factors, plus the $0.80 Energy Assistance Charge ComEd folds into the line, account for $15.39 of the $15.50 printed, and the remaining eleven cents is not on a filed sheet we hold. The delivery section as a whole was $117.44 of a $281.06 bill.
So the honest answer to "why are rates going up" has two parts moving on two calendars: a supply rate that steps at the June procurement boundary, and a delivery rate that steps at the calendar year under a rate order. A bill that rose in June is mostly the first. A bill that rose in January is mostly the second.
What it came to on one reconciled bill
Structure is abstract until it lands on a bill, so here is the one we hold in full. A single-family home in ComEd territory, service from May 1 to June 2, 2026, 1,518 kWh, on ComEd's default supply.
|
|
| Supply section (Electricity Supply Charge, Transmission Services Charge, Purchased Electricity Adjustment) |
$161.35 |
| Delivery section (Customer Charge, Standard Metering Charge, Distribution Facilities Charge, IL Electricity Distribution Charge) |
$117.44 |
| Taxes, fees and credits (nine rider lines and state tax, netting out) |
$2.27 |
| Total |
$281.06 |
| All-in cost per kWh |
18.52 cents |
The bill printed a Price to Compare of 10.399 cents, the ICC's posting for June 2026, and the two agree. The bill's own 13-month usage graph shows June 2025 at 1,519 kWh and June 2026 at 1,518 kWh, the same usage to within one kilowatt hour. The posted rate for June 2025 was 10.028; for June 2026, 10.399. So the difference between those two Junes on this house is 0.371 cents times 1,518 kWh, which is $5.63 on the supply line, with usage flat. Against May 2025, before the big reset, the same 1,518 kWh at 6.552 would have priced the supply and transmission lines $52.77 lower.
That is what "rates going up" looks like on one bill: the same house, the same June, and about $53 a month more on the supply half than two summers earlier, most of it from a single reset.
What does not explain it
Three things get blamed that the record does not support.
Your usage. On the reference bill it was flat year over year. Whether yours is flat is printed on your own bill's usage graph, and a ComEd bill that went up should be checked against that graph before anything else.
ComEd raising its supply price. ComEd does not set the supply price and does not earn a margin on it; Rider PE recovers the procured cost "with no mark-up or return." The rate rose because the procured cost of energy and capacity rose. Whether ComEd is a monopoly is a fair question, and the answer is that it is one on the delivery half and a pass-through on the supply half.
A supplier switch fixing it. A retail supplier's offer replaces the supply section and leaves the delivery section alone. Whether an offer beats the posted rate is a comparison against 10.399 on the same window, and the Price to Compare page keeps that number current.
Check your own bill against the posting
The chart above is the record. The free ComEd bill check reads a bill PDF and checks the Price to Compare it printed against the ICC's posting for the months the bill covers, states the dollar difference when a bill straddles a reset, and compares the posting to the same month a year earlier. It shows what changed in the rate and what changed in the usage, which is the split this whole question turns on.
