Ammonia test cost in St. Louis, MO — inpatient
In St. Louis, MO-IL, 12 hospitals list a cash price for ammonia blood test as an inpatient: from $50.48 to $414.77, with a median of $163.53. The lowest listed price is at Mercy Rehabilitation Hospital South — $113.05 less than the median here. Across Missouri, the median is $76.50 at 64 hospitals.
Cash prices at 12 facilities across 11 cities for code 82140, as an inpatient (admitted to hospital) . Collected Sep 29, 2026; the hospital files themselves were last updated between Feb 6, 2026 and Aug 6, 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 Rehabilitation Hospital South lowest Louis, MO AMMONIA | $50.48 | $50.48 | $50.48 | — | Mar 16, 2026 source file |
| Mercy Rehabilitation Hospital South lowest Louis, MO AMMONIA BLOOD | $50.48 | $50.48 | $50.48 | — | Mar 16, 2026 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 |
| Community Hospital of Staunton Staunton, IL · (618) 635-2200 AMMONIA | $111.15 | $222.30 | $188.96–$202.29 | 50% | Feb 9, 2026 source file |
| Carlinville Area Hospital Carlinville, IL · (217) 854-3141 AMMONIA REF | $123.20 | $176.00 | $109.47–$3,396.04 | 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 | $128.75–$3,396.04 | 30% | — source file |
| Carlinville Area Hospital Carlinville, IL · (217) 854-3141 AMMONIA | $151.90 | $217.00 | $134.97–$3,396.04 | 30% | — source file |
| Anderson Hospital Maryville, IL · (618) 288-5711 AMMONIA | $157.05 | $314.10 | $235.58–$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 |
| Mercy Rehabilitation Hospital St. Louis Chesterfield, MO AMMONIA | $178.23 | $178.23 | $178.23 | — | Mar 16, 2026 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 |
| Mercy Rehabilitation Hospital St. Louis Chesterfield, MO AMMONIA BLOOD | $180.25 | $180.25 | $180.25 | — | Mar 16, 2026 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 |
| St Lukes Rehabilitation Hospital Chesterfield, MO Ammonia | $213.20 | $213.20 | $149.24–$159.90 | — | Aug 6, 2026 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 |
Inpatient: lowest $50.48, median $163.53, highest $414.77 — a 8.2× difference within the same market.
As an outpatient, the same code is billed by 16 facilities here, median $112.83 — that is the price to compare if you are not being admitted.
Cash or insurance?
At 8 of 12 hospitals that publish insurer rates for this code here, the cash price is below the highest rate a health plan has negotiated, and at 3 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.