Ammonia test cost in St. Louis, MO
In St. Louis, MO-IL, 16 hospitals list a cash price for ammonia blood test: from $51.35 to $414.77, with a median of $112.83. The lowest listed price is at Mercy Hospital Lincoln — $61.48 less than the median here. Across Missouri, the median is $76.50 at 64 hospitals.
Cash prices at 16 facilities across 14 cities for code 82140, as an outpatient — the setting a self-pay patient normally buys. Collected Sep 27, 2026; the hospital files themselves were last updated between Feb 6, 2026 and Feb 9, 2026.
Where each hospital's price falls
Each dot is one hospital's cash price on a scale from the lowest to the highest in St. Louis, MO-IL.
Hospitals, cheapest first
| Hospital | Cash price | List price | Insurers pay | Off list | File date |
|---|---|---|---|---|---|
| Mercy Hospital Lincoln lowest Troy, MO · (636) 528-8551 Stone Risk Ua Ammonia | $51.35 | $79.00 | $14.57–$20.64 | 35% | — source file |
| Mercy Hospital St Louis Saint Louis, MO · (314) 251-6000 Stone Risk Ua Ammonia | $57.85 | $89.00 | $5.79–$89.00 | 35% | — source file |
| Mercy Hospital Washington Washington, MO · (636) 239-8000 Stone Risk Ua Ammonia | $65.00 | $100.00 | $6.50–$90.00 | 35% | — source file |
| Mercy Hospital Jefferson Festus, MO · (636) 933-1000 Ammonia | $89.70 | $138.00 | $8.97–$138.00 | 35% | — source file |
| Mercy Hospital Washington Washington, MO · (636) 239-8000 Ammonia | $89.70 | $138.00 | $13.11–$24.66 | 35% | — source file |
| St Elizabeths Hospital of the Hospital Sisters of the Third Order of St Francis O'Fallon, IL · (618) 234-2120 HC AMMONIA | $93.60 | $130.00 | $8.40–$130.00 | 28% | — source file |
| Mercy Hospital South Saint Louis, MO · (314) 525-1000 Stone Risk Ua Ammonia | $102.70 | $158.00 | $13.11–$32.78 | 35% | — source file |
| Mercy Hospital South Saint Louis, MO · (314) 525-1000 Ammonia | $104.00 | $160.00 | $10.40–$160.00 | 35% | — source file |
| Touchette Regional Hospital Cahokia Heights, IL · (618) 332-3060 Ammonia | $104.16 | $168.00 | $6.40–$160.00 | 38% | — source file |
| Community Hospital of Staunton Staunton, IL · (618) 635-2200 AMMONIA | $111.15 | $222.30 | $64.27–$202.29 | 50% | Feb 9, 2026 source file |
| Mercy Hospital Jefferson Festus, MO · (636) 933-1000 Stone Risk Ua Ammonia | $114.40 | $176.00 | $13.11–$32.78 | 35% | — source file |
| Shriners Childrens - St Louis Saint Louis, MO · (314) 432-3600 ASSAY OF AMMONIA | $114.50 | $114.50 | $7.99–$25.04 | — | — source file |
| Mercy Hospital Lincoln Troy, MO · (636) 528-8551 Ammonia | $117.00 | $180.00 | $14.57–$20.64 | 35% | — source file |
| Mercy Hospital St Louis Saint Louis, MO · (314) 251-6000 Ammonia | $117.65 | $181.00 | $13.11–$32.78 | 35% | — source file |
| Carlinville Area Hospital Carlinville, IL · (217) 854-3141 AMMONIA REF | $123.20 | $176.00 | $63.36–$251.43 | 30% | — source file |
| Hshs Holy Family Hospital Greenville, IL · (618) 664-1230 ASSAY OF AMMONIA | $130.32 | $181.00 | $8.82–$181.00 | 28% | — source file |
| Carlinville Area Hospital Carlinville, IL · (217) 854-3141 URINE 24 HOUR AMMONIA(REF) | $144.90 | $207.00 | $74.52–$295.71 | 30% | — source file |
| Carlinville Area Hospital Carlinville, IL · (217) 854-3141 AMMONIA | $151.90 | $217.00 | $78.12–$310.00 | 30% | — source file |
| Anderson Hospital Maryville, IL · (618) 288-5711 AMMONIA | $157.05 | $314.10 | $13.62–$282.69 | 50% | Feb 6, 2026 source file |
| Jersey Community Hospital Jerseyville, IL · (618) 498-6402 Ammonia Level | $170.00 | $170.00 | $88.91–$144.50 | — | — source file |
| St Josephs Hospital of the Hospital Sisters of the Third Order of St Francis Highland, IL · (618) 651-2600 HC AMMONIA | $178.56 | $248.00 | $19.56–$248.00 | 28% | — source file |
| St Josephs Hospital Hospital Sisters Third Order of St Francis Breese, IL · (618) 526-4511 HC AMMONIA | $182.88 | $254.00 | $8.40–$254.00 | 28% | — source file |
| Gateway Regional Medical Center Granite City, IL · (618) 798-3000 Q442 AMMONIA | $414.77 | $691.29 | $691.29 | 40% | — source file |
| Gateway Regional Medical Center Granite City, IL · (618) 798-3000 L910235 AMMONIA | $414.77 | $691.29 | $691.29 | 40% | — source file |
Outpatient: lowest $51.35, median $112.83, highest $414.77 — a 8.1× difference within the same market.
As an inpatient, the same code is billed by 12 facilities here, median $163.53. Inpatient and outpatient prices are not comparable and are kept on separate pages: the inpatient charge covers admission, not the same purchase.
Cash or insurance?
At 12 of 16 hospitals that publish insurer rates for this code here, the cash price is below the highest rate a health plan has negotiated, and at 1 it is below every plan's rate. If you have insurance but have not met your deductible, you usually pay your plan's negotiated rate, which falls somewhere in the "Insurers pay" column. Paying cash can cost less, but a cash payment usually does not count toward your deductible. Ask the hospital for both numbers before you book.
What it is
An ammonia test measures ammonia in the blood. It is used for confusion or drowsiness in people with liver disease and for some rare inherited disorders in newborns.
What the price covers
The price usually covers running the test. The blood draw (36415) is often billed as a separate line.