Peoples Gas Chicago Alternative Suppliers: What to Know Before Winter

As Chicago heads toward another heating season, it's worth understanding exactly how your Peoples Gas bill is priced — and what shopping for an alternative supplier would actually change, before committing to anything.

How Peoples Gas Prices Its Default Rate

Peoples Gas doesn't set its own gas supply price. Like every Illinois gas utility, it uses a mechanism called the Purchased Gas Adjustment (PGA) — the monthly cost of the gas it buys on the wholesale market, passed through to customers with no markup. Under Illinois law, gas utilities aren't permitted to profit on this portion of your bill at all; what Peoples Gas pays for gas is exactly what you pay. The Illinois Commerce Commission (ICC) reviews these filings annually and can order refunds if a utility wasn't purchasing gas at a reasonable cost.

Peoples Gas publishes this as its Price to Compare (PTC), updated quarterly on January 1, April 1, July 1, and October 1 based on current market conditions. As of the most recent quarter, Peoples Gas's supply rate has run modestly higher year-over-year — about 6% above where it was a year earlier, according to the Citizens Utility Board's monthly market tracking — though that's meaningfully smaller than the swings some other Illinois gas utilities have seen in the same period.

What Alternative Gas Suppliers (AGS) Actually Are

Illinois deregulated its natural gas market, which means Peoples Gas customers can choose to buy their gas commodity from a certified Alternative Gas Supplier instead of Peoples' own PGA-based rate. Peoples still delivers the gas either way — the pipes, the safety response, the meter reading all stay the same regardless of who you buy the commodity from. An AGS sets its own price under a private contract, rather than the monthly PGA formula.

Why This Market Deserves More Caution Than Electricity Shopping

Here's the part worth taking seriously before switching: the Citizens Utility Board, Illinois's independent consumer watchdog, has specifically cautioned that because utility gas prices are already a no-markup pass-through, alternative suppliers often struggle to consistently beat it — and CUB has gone as far as advising that, as volatile as utility gas prices are, sticking with the utility is frequently the safer bet over an alternative supplier. Their guidance is blunt: watch for alternative supplier offers that seem too good to be true, since teaser rates and fixed introductory pricing can convert to a much higher rate once the promotional period ends.

That's a meaningfully different dynamic than the electricity market, where a fixed-rate alternative supplier competing against a utility's supply charge is a much more established way to find real savings. For gas specifically, the smart move is treating any AGS offer with real scrutiny rather than assuming a lower headline number is automatically the better deal.

How to Actually Evaluate an Offer

Before signing anything, compare the AGS contract's per-therm price directly against Peoples Gas's current published PTC, and pay close attention to whether the AGS rate is fixed for the full contract term or can adjust — a variable "market-based" AGS rate defeats the purpose of switching away from the utility's monthly PGA fluctuation in the first place.

Upload your Peoples Gas bill to Maya AI before you commit to anything, and it'll pull your current PTC and usage directly off the statement — giving you a clear, apples-to-apples number to hold any alternative supplier offer against before winter heating season drives your usage up.

Check your Peoples Gas rate with Maya AI →