The transaction was reported at $34.5 million. It will change who owns and manages water service for customers in Neosho, while placing the system under Missouri American Water’s administration and the commission’s regulatory oversight.

What the approval covers

The PSC case, docket WA-2026-0072, concerns Missouri American Water’s authority to acquire, construct, operate, control, manage and maintain a water and sewer system in and around the City of Neosho.

The approved plan involves more than a change in administration. Missouri American Water is expected to purchase the system and carry out upgrades as part of the transaction. The commission’s action authorizes the company’s role in the system, but it does not mean the acquisition has necessarily closed on the same date as the approval.

For Neosho residents, the practical effects may eventually include changes in billing contacts, service administration, capital work and how future utility decisions are reviewed. The approval itself does not establish that customer rates will rise or fall.

Public process preceded decision

The PSC docket records local public-hearing activity in Neosho on Dec. 8, 2025. The case also includes a settlement-related filing dated June 10, 2026, before the commission’s June 24 decision.

That timeline places the approval after months of formal regulatory activity and local participation. The docket identifies the system as serving areas in and around Neosho, making the case a municipal utility change with direct importance for local water customers.

What remains ahead

The Missouri PSC docket and the June 25 report on the decision do not state a final customer-rate schedule, a closing date or a detailed timetable for the upgrades. They also do not identify the exact assets transferred in the acquisition.

Those details will determine when customers see operational changes and how the planned improvements are carried out. Until those steps are documented, the confirmed development is the commission’s approval of Missouri American Water’s acquisition, upgrade and administration of Neosho’s water system.

Ameren Missouri filed for the PSC to approve about $343 million in additional annual electric base-rate revenue—something Ameren says would equal about $13 more per month for the average residential customer if approved.

Ameren’s request: $343 million more a year in electric base rates

In a press release about the case, the PSC says the company requested a net increase in annual electric base-rate revenues of approximately $343 million, equating to an increase of approximately $13.00 per month for the average residential customer.

Deadline: intervene by July 15, 2026

The PSC set July 15, 2026 as the deadline for customers and other parties to intervene and participate in the rate case.

The PSC press release says applications to intervene should be filed with the PSC Secretary (via the PSC’s Electronic Filing and Information System, EFIS, or by mail) and that comments should use the related submission number ER-2026-0291.

The PSC also notes local public hearings have not yet been scheduled in the case; when they are, customers will be notified and will be able to provide comments as the proceeding moves forward.

What to expect next—and when rates could change

PSC decisions require commission approval of the utility’s proposed base rates. The PSC says it typically has 11 months from the date a rate case is filed to make a decision.

Ameren’s June 26 filing materials project a PSC decision deadline in May 2027 and state that new rates could be effective by June 1, 2027 if approved.

Bottom line: this is a proposal, not a final decision. The PSC can modify what’s allowed, and the final impact will vary by customer.

Why St. Louis-area residents are directly connected

Ameren Missouri’s service territory includes the greater St. Louis area. In its fact sheet, Ameren Missouri says it provides electric service to approximately 1.3 million customers across central and eastern Missouri, including the greater St. Louis area—and that more than half of its electric customers are located in the greater St. Louis region.

Possible bill relief for some customers (not for everyone)

KRPS/ St. Louis Public Radio reports that Ameren Missouri is asking to implement a new discount rate for customers who have trouble paying their bills.

As KRPS describes it, customers with annual income less than 150% of the federal poverty line—reported by KRPS as $23,914 for an individual and $49,500 for a four-person household—would get a 20% discount. Other ratepayers could qualify for a 10% discount.

Even if a discount program is proposed, the July 15, 2026 intervention deadline is still the first concrete step residents can take while the PSC is reviewing the request.

What you can do now

• Mark your calendar: plan to intervene/participate by July 15, 2026.
• Decide what you want the PSC to hear: whether you support, oppose, or want changes to specific parts of the proposed electric base-rate request.
• Remember the timing: the proposal—if approved—would potentially affect bills starting in mid-2027, based on Ameren’s projected effective date.

This case will likely shape near-future electric costs across Ameren Missouri’s St. Louis region—so if you care about how rates are set, the window to participate is now.

Sources

• Missouri Public Service Commission (PSC) press release: intervention deadline set for Ameren Missouri general rate case
• Ameren Missouri electric rate review filing (June 26, 2026 PDF)
• KRPS / St. Louis Public Radio: what the request could mean for bills and how PSC participation/relief works
• St. Louis Business Journal: Ameren seeks $343M annual increase—context for the proposal and local timing
• Ameren Missouri fact sheet: service territory includes greater St. Louis area

Ameren Missouri says its proposal would seek a net increase of about $343 million in annual electric base-rate revenues—an amount the PSC describes as about $13 per month for the average residential customer if approved.

ER-2026-0291 in plain English: “electric base rates”

“Electric base rates” are the core rates Ameren charges for providing electricity (before many bill items that can vary by usage, rider programs, and other factors). In a general rate case, the company proposes changes to those base rates, and the PSC evaluates whether they are just and reasonable.

What Ameren is asking for (and when it says new rates could start)

In the materials tied to the PSC filing, Ameren Missouri lists a $343 million revenue increase request in ER-2026-0291. Ameren also cites a company-requested timeline of a MoPSC decision deadline of May 2027, with new rates effective by June 1, 2027 if approved.

Local public hearings have not been scheduled yet. When hearings are scheduled, PSC says customers will be notified directly by Ameren Missouri and the PSC.

Intervene vs. submit comments: two different ways to be heard

Intervene and participate (active party status): If you want a formal role in the case, the PSC set July 15, 2026 as the deadline for applications to intervene.

Submit comments (public input): Even if you don’t intervene, you may still be able to share feedback while the PSC review is underway. PSC says customers can submit comments by mail, telephone, email, or online via EFIS, and that comments should use the related submission number ER-2026-0291.

What to watch next on the PSC timeline

On the PSC’s EFIS case calendar for ER-2026-0291, the next procedural steps shown include:

• July 15, 2026: applications to intervene due
• July 22, 2026: parties submit a joint proposed procedural schedule (and response items are also due)

The PSC press release also notes that the Commission typically has about 11 months from the date the rate case is filed to make a decision on a rate proposal—so a decision is expected on a next-year horizon if the timeline holds.

What local reporting says about potential bill impact

Local public media (KRPS) reported that Ameren Missouri’s request is about a 10% increase, described as roughly $13 a month for the average residential bill, with the new rate taking effect in mid-2027 if approved. Those figures are still proposals—your final bill impact depends on what the PSC orders.

If you’re an Ameren customer in St. Louis: a quick checklist

• Before July 15, 2026: decide whether you want to intervene and participate (formal role) or only submit comments (public input).
• As the case proceeds: track updates on the PSC’s EFIS page for ER-2026-0291.
• When hearings are scheduled: watch for Ameren and PSC notifications about local public hearing dates.
• Keep in mind: the intervention deadline is not the same thing as submitting comments—so follow the path that matches your level of involvement.

Bottom line

The immediate St. Louis deadline is July 15, 2026 for intervening in ER-2026-0291. Local hearings are not scheduled yet, but PSC review can shape electric base rates that—if approved as requested—could affect bills starting in 2027.

Sources

• Missouri Public Service Commission press release (PR-27-01): Intervention deadline set for Ameren Missouri general rate case (ER-2026-0291)
• Missouri PSC EFIS calendar entry for ER-2026-0291 (shows procedural timing, including intervention-related due date)
• Ameren Missouri electric rate review filing (ER-2026-0291) PDF
• KRPS / St. Louis Public Radio: Bill impact framing and summary of the PSC review process