Natural Gas Choice

Rider S (System Gas Service) is available to all residential customers and those non-residential customers that do not wish to procure gas supply through a Retail Gas Supplier.

Rider T is available to those non-residential customers who purchase their own natural gas and deliver it into Ameren Illinois' distribution system. The customer or the customers supplier, as applicable is responsible for acquiring gas supply and delivery of those supplies to Ameren Illinois' Citygate. The cost to acquire gas and deliver it to the Ameren Illinois delivery system is at the supplier's or customer's expense. If you're interested in enrolling into Rider T, to be effective May 1st enrollments must be submitted during the annual enrollment period which typically commences in mid-February. Please call Ameren Illinois at 1.800.232.2477 for more information.

For more information on your supply options see our Non-residential Natural Gas Service Tariffs.

To decide if choice is right for you, learn more about the price of natural gas.

Since natural gas is a commodity, its price varies daily based on the effects of weather, supply and demand. Because prices change so much, it's important to look at your gas cost for a full year or two, not just for one month.

The cost of your natural gas supply currently makes up about 75 to 80 percent of your annual gas bill; the rest is delivery charges and taxes. Ameren Illinois' cost for natural gas changes every month and this change is filed with the Illinois Commerce Commission (ICC), which regulates all Illinois utilities and is listed as Purchase Gas Adjustment.

Prices charged by the participating suppliers, as well as the terms and conditions of their contracts with you are not regulated by the ICC. Because of this, suppliers are able to create a variety of pricing offers. Please consider talking to different suppliers to find out about their pricing options, services, incentives and/or promotions.

• Rider S (System Gas Service) - Is available to all Residential Gas Customers or those Non-Residential Customers that do not wish to procure gas supply through a Retail Gas Supplier.
• Rider T - Available to those Non-Residential Customers who purchase their own natural gas and deliver it into Ameren Illinois’ Distribution System. The Customer or the Customers Supplier, as applicable shall be responsible for acquiring gas supply and delivery of those supplies to Ameren Illinois’ City gate. The cost to acquire gas and deliver it to the Ameren Illinois delivery system shall be at the Supplier’s or Customer’s expense.

View the list of cities for information on pipeline locations.

Use our weather forecasting tool to view temperatures.

Available to daily-balanced Customers taking service under Rider T. All monthly balanced Customers are required to take service under Rider TBS. This rider provides a subscribable banking service which allows Customers to bank excess gas delivered to the Company’s gas system. Similarly, customers can withdraw excess gas deliveries to offset an under delivery. Customers will select the amount of banking service on an annual basis and their Supplier will notify Ameren Illinois of the Customers Bank Elections.

Imbalances will be cashed out at the specified cash out price as described in Rider T. However if subscribed to Rider TBS, Customers can utilize the banking service in the event of an over delivery.

At this time, Rider T customers are exempt from Summary Billing.

If your question is concerning the supply cost, please contact your supplier.


If your question is concerning the delivery charges, please contact Ameren Illinois.

Dual Billing is the only option available to Rider T customers. A customer on Dual Billing receives an Ameren Illinois bill for the gas delivery services and receives a bill from their supplier for the gas supply charges.

Customers can elect to purchase gas from suppliers while still relying on Ameren Illinois to deliver the gas supply to their business. Typically the Customer works with a supplier/marketer, whom contracts to provide a certain quantity of gas for delivery over a specified period of time. Generally, marketers/suppliers can purchase gas on Customer behalf and assist with load balancing. You can find a list of suppliers here.

Within 3 billing periods of the initial connection of service.  

Annual enrollment period.

• To be effective May 1, enrollments must be submitted during the annual enrollment period which typically commences in February. Please call Ameren Illinois at 800.232.2477 for more information.  Selection is effective May 1. 

Once a Customer is on Rider T Ameren Illinois has no limitations for switching suppliers; though, only one switch can be made monthly. However, Customers will need to check with their supplier to verify there are no switching/termination fees.

Please contact your chosen supplier. The supplier will enroll your account via an Electronic Data Interchange on your behalf.

A Customer has the opportunity to rescind the switch within 10 business days after the date on the notice. 

If notification is not received within the 10 business day window, the account shall remain as is.

You will receive a confirmation letter from Ameren Illinois notifying you of the change confirmation.

A gas portal was created, in addition in the Business Partner Portal, for gas suppliers to access usage information for an account at AmerenIllinois.

You must log in to your account to view this information.

Imbalances will be cashed out at the specified cash out price as described in Rider T. However if subscribed to Rider TBS, Customers can utilize the banking service to supplement under delivery.