Rheumatoid factor test cost in St. Louis, MO
In St. Louis, MO-IL, 11 hospitals list a cash price for rheumatoid factor (RF) test: from $20.15 to $181.44, with a median of $50.05. The lowest listed price is at Mercy Hospital St Louis and 2 other hospitals — $29.90 less than the median here. Across Missouri, the median is $36.04 at 28 hospitals.
Cash prices at 11 facilities across 9 cities for code 86431, as an outpatient — the setting a self-pay patient normally buys. Collected Sep 23, 2026; the hospital files themselves were last updated between — and —.
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 St Louis lowest Saint Louis, MO Rheumatoid Factor Quantitative | $20.15 | $31.00 | $5.10–$12.76 | 35% | — source file |
| Mercy Hospital South lowest Saint Louis, MO · (314) 525-1000 Rheumatoid Factor Quantitative | $20.15 | $31.00 | $2.02–$31.00 | 35% | — source file |
| Mercy Hospital Jefferson lowest Festus, MO Rheumatoid Factor Quantitative | $20.15 | $31.00 | $2.02–$31.00 | 35% | — source file |
| Gateway Regional Medical Center Granite City, IL · (618) 798-3000 RHEUMATOID FACT QUAN | $33.51 | $55.85 | $55.85 | 40% | — source file |
| Shriners Childrens - St Louis Saint Louis, MO · (314) 432-3600 RHEUMATOID FACTOR QUANT | $49.00 | $49.00 | $3.02–$9.75 | — | — source file |
| Mercy Hospital Washington Washington, MO Rheumatoid Factor Quantitative | $50.05 | $77.00 | $5.10–$9.60 | 35% | — source file |
| Mercy Hospital Lincoln Troy, MO · (636) 528-8551 Rheumatoid Factor Quantitative | $74.75 | $115.00 | $5.67–$8.04 | 35% | — source file |
| St Josephs Hospital Hospital Sisters Third Order of St Francis Breese, IL · (618) 526-4511 HC RHEUMATOID FACTOR QN | $85.68 | $119.00 | $5.67–$119.00 | 28% | — source file |
| Hshs Holy Family Hospital Greenville, IL · (618) 664-1230 RHEUMATOID FACTOR QUANT | $100.08 | $139.00 | $5.67–$139.00 | 28% | — source file |
| St Josephs Hospital of the Hospital Sisters of the Third Order of St Francis Highland, IL · (618) 651-2600 HC RHEUMATOID FACTOR QN | $112.32 | $156.00 | $11.34–$156.00 | 28% | — source file |
| St Elizabeths Hospital of the Hospital Sisters of the Third Order of St Francis O'Fallon, IL HC RHEUMATOID FACTOR QN | $181.44 | $252.00 | $5.67–$252.00 | 28% | — source file |
Outpatient: lowest $20.15, median $50.05, highest $181.44 — a 9.0× difference within the same market.
As an inpatient, the same code is billed by 7 facilities here, median $100.08. 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 7 of 11 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
Rheumatoid factor is an antibody found in many people with rheumatoid arthritis. The test is part of the workup for joint pain and swelling.
What the price covers
The price usually covers running the test. The blood draw (36415) is often billed as a separate line.