AEE · 10-Q · 2026Q3 · Full report

Missouri Utility Regulatory Changes

AMEREN CORP · 2026-11-06 · Importance 40 · Surprise 42 · In source text

Missouri’s PPRA, effective in 2025, changes integrated resource planning and requires the MoPSC to publish a filing schedule by August 2027 for four-year plans. If the MoPSC approves a plan, qualifying new generation projects may receive streamlined CCN review and may include construction work in progress in rate base, subject to approval and statutory limits. The law extends Ameren Missouri’s PISA election through 2035, permits a requested and approved extension through 2040, and changes the applicable annual electric revenue-requirement increase limit from 2.5% to 2.25% for rate requirements approved after August 2025. It also allows natural-gas utilities to seek future-test-year rate reviews and permits construction work in progress for new natural-gas generation in rate base, with that provision expiring in December 2035 unless extended.

Key facts

• Under the PPRA, Ameren Missouri’s PISA election was extended through 2035, with a possible extension through 2040 if Ameren Missouri requests and the MoPSC approves it.
• The PPRA’s provisions allowing construction work in progress for natural-gas-fired generation in rate base expire in December 2035 unless Ameren Missouri obtains MoPSC approval to extend them through 2045.
• The PPRA requires the MoPSC to publish, by August 2027, a schedule for Missouri electric utilities to file integrated resource plans every four years.
• The PPRA reduced the annual limit on increases to Ameren Missouri’s electric service revenue requirement from 2.5% to 2.25%, prorated monthly, for revenue requirements approved by the MoPSC after August 2025.
• Ameren Missouri expects significantly higher allowance for equity funds used during construction and PISA-eligible infrastructure investment in 2026 compared with 2025, and in 2027 compared with 2026.
• Ameren Missouri can defer and recover 85% of depreciation expense for qualifying property, plant, and equipment placed in service and not included in base rates under the PISA.

Impact estimates