---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-23-126540"
form_type: "8-K"
ticker: "AEE"
cik: "0001002910"
company_name: "AMEREN CORP"
filed_at: "2023-12-18T23:59:59+00:00"
generated_at: "2026-06-07T11:04:27.323995+00:00"
event_type: "regulatory"
sentiment: "negative"
materiality_score: 0.78
calibrated_materiality_score: 0.78
confidence: "high"
source: SEC EDGAR
---

# ICC rejects Ameren Illinois grid plan; approves $142M revenue increase vs $444M requested

## Summary
- ICC rejected Ameren Illinois' 5-year grid plan and adopted alternative rate-setting methodology through 2027.
- Approved cumulative revenue increase of $142M (corrected) vs $444M requested; ROE set at 8.72% with 50% equity.
- Rate base frozen at $3.872B (2022 year-end) until revised grid plan approved; 2023 rate base estimate $4.3B.
- Ameren Illinois may cut capex and opex; will seek rehearing and may appeal; reconciliation cap set at 105%.
- Electric rates effective Jan 1, 2024; existing riders and revenue decoupling remain in place.

## SEC filing metadata
- accession: 0001104659-23-126540
- form_type: 8-K
- ticker: AEE
- cik: 0001002910
- company_name: AMEREN CORP
- filed_at: 2023-12-18T23:59:59+00:00
- event_type: regulatory
- sentiment: negative
- materiality_score: 0.78
- calibrated_materiality_score: 0.78
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1002910/000110465923126540/0001104659-23-126540-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/18654/000110465923126540/tm2333080d1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-23-126540
- JSON: https://secwatch.observer/filing/0001104659-23-126540.json
- Plain text: https://secwatch.observer/filing/0001104659-23-126540.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.