AC Replacement Cost in St. Louis, MO (2026)
A 3-ton central air conditioner, installed, before rebates
$4,150to$9,700
From a public baseline and 131 City permits. How prices are made.
The low and the high are the spread of equipment and labor in the public baseline for a 3-ton central air conditioner in 2026.
Missouri Rebates in 2026
Enrollment for 2026 is closed. Whole Home PAYS and FastTrack HVAC PAYS are not accepting enrollments for 2026. Ameren says the program is fully subscribed for 2026. Count on the rebate for a later install.
Ameren Missouri pays $1,000 on a central air conditioner at 15.2+ SEER2. After the rebate the typical price for a 3-ton central air conditioner is $5,900. The chart runs from January 1, 2026 to December 31, 2026. Checked October 19, 2026. How to apply.
| Equipment | Minimum efficiency | Rebate |
|---|---|---|
| Central air conditioner | 15.2+ SEER2 | $1,000 per system |
| Air-source heat pump (ducted) | 15.2+ SEER2 | $2,000 per system |
Every Program a St. Louis Homeowner Can Use
- Ameren PAYS pays up to $2,000 per system. Closed for 2026.
- Spire furnace rebates pay up to $300 per furnace. Open now.
- Missouri HOMES and HEEHR have not published their amounts yet. Not open yet.
- Federal 25C credit gives no credit for a 2026 install. Ended.
What It Costs
All 7 systems, low to high
| System | Low | Typical | High | Range drawn |
|---|---|---|---|---|
| Heat pump, ducted | ||||
| 2-ton heat pump 15 SEER | $6,500 | $11,750 | $17,000 | |
| 3-ton heat pump 15 SEER | $7,450 | $13,350 | $19,250 | |
| 4-ton heat pump 15 SEER | $8,400 | $14,950 | $21,500 | |
| 5-ton heat pump 15 SEER | $9,400 | $16,550 | $23,700 | |
| Other systems | ||||
| Central AC only, 3 ton 16 SEER | $4,150 | $6,900 | $9,700 | |
| Gas furnace only, 80,000 BTU 95% AFUE | $3,750 | $4,050 | $4,800 | |
| Mini-split, one zone, 12,000 BTU 20 SEER | $4,500 | $7,500 | $10,500 | |
Sources today: public baseline: NREL National Residential Efficiency Measures Database, 2024 release (read via hvacbase.org, 2026-10-19) · 131 City permits (2026-09-17 to 2026-10-16). Two more sources join as they arrive: Verified contractor ranges and homeowner-reported quotes. 2023 dollars, national. No metro factor is applied in this version. How prices are made.
Permits
Your contractor pulls the permit. The City issues mechanical permits only to contractors it licenses. The application fee is $25. The most common total fee on a replacement permit was $40 (97 of 131 permits). St. Louis County Department of Public Works covers homes in St. Louis County outside the city, with its own schedule.
The City issued 131 residential replacement permits in the 30 days from September 17, 2026 to October 16, 2026. Contractors declared a job value of $6,495 to $12,839 on the middle half of them, with a median of $9,954. Declared valuation on the permit. Contractors under-report it, so read it as a floor. Source: City of St. Louis Building Division · the open permit data.
Common Questions
How much does a 3-ton central air conditioner cost installed in St. Louis?
The installed range is $4,150 to $9,700, with a typical price of $6,900. This is the national public baseline in 2023 dollars. After the rebate the typical price for a 3-ton central air conditioner is $5,900. Enrollment for 2026 is closed, so count on it for a later install.
What does the Ameren Missouri central air conditioner rebate pay in 2026?
$1,000 per central air conditioner at 15.2+ SEER2, through Ameren PAYS. Whole Home PAYS and FastTrack HVAC PAYS are not accepting enrollments for 2026. Ameren says the program is fully subscribed for 2026.
Is there a federal tax credit for a 3-ton central air conditioner in 2026?
The federal credit ended for equipment placed in service after December 31, 2025. The utility rebate is the money on the table in 2026.
Do I need a permit to replace a central air conditioner in the City of St. Louis?
Yes. The City issues mechanical permits only to contractors it licenses. The most common total fee was $40. The City issued 131 residential replacement permits in 30 days.
What do the other systems cost in St. Louis?
A gas furnace runs $3,750 to $4,800, typical $4,050. A 3-ton heat pump runs $7,450 to $19,250, typical $13,350. A one-zone mini-split runs $4,500 to $10,500, typical $7,500. Each range is installed, before rebates.
What did contractors declare on the permits?
A median of $9,954 on 131 replacement permits. Declared valuation on the permit. Contractors under-report it, so read it as a floor.
Contractors in St. Louis
47 contractors pulled a residential replacement permit in the City in the last 30 days. A Verified contractor is one that published its terms here. Contractors in St. Louis.
Range quarter 2026-Q4, updated October 19, 2026. Last change: First page. Range 2026 Q4 from the public baseline and 131 City permits. Four rebate pages. Changelog. Source page: https://hvacvisit.com/missouri/st-louis/ac-replacement-cost. Cite a range with a link to the page it is on. Do not republish a page, a table or a dataset in full.