Rheumatoid factor test cost in San Andreas, CA — inpatient
In San Andreas, CA, 1 hospital lists a cash price for rheumatoid factor (RF) test as an inpatient: from $16.65 to $16.65, with a median of $16.65. Across California, the median is $13.00 at 142 hospitals.
Cash prices at 1 facility for code 86431, as an inpatient (admitted to hospital) . Collected Sep 27, 2026; the hospital files themselves were last updated between Feb 28, 2026 and Feb 28, 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 San Andreas, CA.
Hospitals, cheapest first
| Hospital | Cash price | List price | Insurers pay | Off list | File date |
|---|---|---|---|---|---|
| Mark Twain Medical Center lowest San Andreas, CA · (209) 754-3521 RL-A-ILD PANEL2 3018869D | $16.65 | $25.00 | $13.54–$24.50 | 33% | Feb 28, 2026 source file |
| Mark Twain Medical Center San Andreas, CA · (209) 754-3521 RHEUMATOID FACTOR QN | $64.61 | $97.00 | $52.51–$95.06 | 33% | Feb 28, 2026 source file |
Inpatient: lowest $16.65, median $16.65, highest $16.65.
As an outpatient, the same code is billed by 1 facility here, median $16.65 — that is the price to compare if you are not being admitted.
Cash or insurance?
At the one hospital here that publishes insurer rates for this code, the cash price is below the highest rate a health plan has negotiated. 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.
1 row held back from this comparison
It is priced below $1 or below a tenth of the national median for code 86431 ($44.73). Such a line is almost always a physician's fee billed separately, an assistant's share or a placeholder — a real charge, but not the price of the procedure itself.
| Mark Twain Medical Center San Andreas, CARL-A-LUPUS COMP 50119C | $4.17 | file |