Lab tests CPT 86431 Inpatient — admitted to hospital

Rheumatoid factor test cost in Los Angeles, CA — inpatient

In Los Angeles-Long Beach-Anaheim, CA, 25 hospitals list a cash price for rheumatoid factor (RF) test as an inpatient: from $7.90 to $187.60, with a median of $13.00. The lowest listed price is at Cedars-Sinai Medical Center — $5.10 less than the median here. Across California, the median is $13.20 at 93 hospitals.

Cash prices at 25 facilities across 20 cities for code 86431, as an inpatient (admitted to hospital) . Collected Sep 23, 2026; the hospital files themselves were last updated between Nov 26, 2025 and Jul 27, 2026.

Lowest$7.90Cedars-Sinai Medical Center
Median$13.00half pay less
Highest$187.60in this market
Difference23.7×highest vs lowest

Where each hospital's price falls

Each dot is one hospital's cash price on a scale from the lowest to the highest in Los Angeles-Long Beach-Anaheim, CA.

median
Lowest $7.90Highest $187.60

Hospitals, cheapest first

HospitalCash price List priceInsurers payOff listFile date
Cedars-Sinai Medical Center lowest Los Angeles, CA · (310) 423-5000 HB LAB RA, IGG, IGA, IGM $7.90 $12.15 $13,270.00–$14,761.00 35% Nov 26, 2025
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Cedars-Sinai Medical Center lowest Los Angeles, CA · (310) 423-5000 HB LAB ANTIB RA QUANT $7.90 $12.15 $13,270.00–$14,761.00 35% Nov 26, 2025
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Mission Hospital Regional Med Center Mission Viejo, CA · (949) 364-1400 HC RHEUMATOID FACTOR QUANTITATIVE LAB $8.16 $17.00 — 52% Apr 1, 2026
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St Joseph Hospital of Orange Orange, CA · (714) 633-9111 HC RHEUMATOID FACTOR QUANTITATIVE LAB $8.16 $17.00 — 52% Apr 1, 2026
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St Jude Hospital Fullerton, CA · (714) 992-3000 HC RHEUMATOID FACTOR QUANTITATIVE LAB $8.16 $17.00 — 52% Apr 1, 2026
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Hoag Memorial Hospital Presbyterian Newport Beach, CA · (949) 764-4624 HC Rheumatoid Factor Quant - Ana W/Reflex to Titer $9.20 $14.16 — 35% Apr 1, 2026
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Cedars-Sinai Marina Hospital Marina del Rey, CA · (310) 823-8911 HB LAB ANLZR - RHEUM FAC, QUANT $10.74 $16.53 $7,175.00–$9,712.00 35% Nov 26, 2025
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Kaiser Foundation Hospital - Los Angeles Los Angeles, CA · (323) 783-4011 RHEUMATOID FACTOR QUANTITATIVE $13.00 $25.00 $3.00–$10.00 48% —
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Kaiser Foundation Hospital - Woodland Hills Woodland Hills, CA · (818) 719-3800 RHEUMATOID FACTOR QUANTITATIVE $13.00 $25.00 $3.00–$10.00 48% —
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Kaiser Foundation Hospital - Orange County - Irvine Irvine, CA RHEUMATOID FACTOR QUANTITATIVE $13.00 $25.00 $3.00–$10.00 48% —
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Kaiser Foundation Hospital - Panorama City Panorama City, CA · (818) 375-2000 RHEUMATOID FACTOR QUANTITATIVE $13.00 $25.00 $3.00–$10.00 48% —
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Kaiser Foundation Hospital - Downey Downey, CA · (562) 461-6007 RHEUMATOID FACTOR QUANTITATIVE $13.00 $25.00 $3.00–$10.00 48% —
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Kaiser Foundation Hospital - Orange County - Anaheim Anaheim, CA · (714) 279-4000 RHEUMATOID FACTOR QUANTITATIVE $13.00 $25.00 $3.00–$10.00 48% —
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Kaiser Foundation Hospital - South Bay Harbor City, CA · (310) 325-5111 RHEUMATOID FACTOR QUANTITATIVE $13.00 $25.00 $3.00–$10.00 48% —
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Kaiser Foundation Hospital - Baldwin Park Baldwin Park, CA · (626) 851-1011 RHEUMATOID FACTOR QUANTITATIVE $13.00 $25.00 $3.00–$10.00 48% —
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Kaiser Foundation Hospital - West la Los Angeles, CA · (213) 857-2201 RHEUMATOID FACTOR QUANTITATIVE $13.00 $25.00 $3.00–$10.00 48% —
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St Jude Hospital Fullerton, CA · (714) 992-3000 HC RHEUMATOID FACTOR QUANT $16.80 $35.00 — 52% Apr 1, 2026
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St Joseph Hospital of Orange Orange, CA · (714) 633-9111 HC RHEUMATOID FACTOR QUANT $16.80 $35.00 — 52% Apr 1, 2026
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Mission Hospital Regional Med Center Mission Viejo, CA · (949) 364-1400 HC RHEUMATOID FACTOR QUANT $16.80 $35.00 — 52% Apr 1, 2026
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Providence Holy Cross Medical Center Mission Hills, CA · (818) 365-8051 HC RHEUMATOID FACTOR QUANT $42.35 $121.00 — 65% Apr 1, 2026
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Providence Holy Cross Medical Center Mission Hills, CA · (818) 365-8051 HC RHEUMATOID FACTOR QUANTITATIVE LAB $42.35 $121.00 — 65% Apr 1, 2026
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USC Arcadia Hospital Arcadia, CA · (626) 898-8000 RF (RHEUMATOID FACTOR) QT $52.85 $151.00 $113.25–$151.00 65% Jul 27, 2026
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Providence Saint Joseph Medical Center Burbank, CA · (818) 843-5111 HC RHEUMATOID FACTOR QUANTITATIVE LAB $60.55 $173.00 — 65% Apr 1, 2026
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Providence Saint Joseph Medical Center Burbank, CA · (818) 843-5111 HC RHEUMATOID FACTOR QUANT $60.55 $173.00 — 65% Apr 1, 2026
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Keck Hospital of USC Los Angeles, CA · (323) 442-8656 Rheumatoid Factor Quant $62.50 $62.50 — — Apr 1, 2026
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Providence Cedars Sinai Tarzana Medical Center Tarzana, CA · (818) 881-0800 HC RHEUMATOID FACTOR QUANT $64.75 $185.00 — 65% Apr 1, 2026
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Providence Cedars Sinai Tarzana Medical Center Tarzana, CA · (818) 881-0800 HC RHEUMATOID FACTOR QUANTITATIVE LAB $64.75 $185.00 — 65% Apr 1, 2026
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UCI Health-Orange Orange, CA · (714) 456-7890 HB RHEUMATOID FACTOR QUANTITATIVE $68.00 $170.00 — 60% Apr 1, 2026
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USC Kenneth Norris Jr Cancer Hospital Los Angeles, CA Rheumatoid Factor Quant $76.25 $76.25 — — Apr 1, 2026
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Providence Little Company of Mary Medical Center Torrance Torrance, CA · (310) 540-7676 HC RHEUMATOID FACTOR QUANT - RA TITER $83.65 $239.00 — 65% Apr 1, 2026
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Providence Little Co of Mary Medical Center San Pedro San Pedro, CA · (310) 832-3311 HC RHEUMATOID FACTOR QUANTITATIVE LAB $83.65 $239.00 — 65% Apr 1, 2026
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Providence Little Co of Mary Medical Center San Pedro San Pedro, CA · (310) 832-3311 HC RHEUMATOID FACTOR QUANT $83.65 $239.00 — 65% Apr 1, 2026
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Providence Little Co of Mary Medical Center San Pedro San Pedro, CA · (310) 832-3311 HC RHEUMATOID FACTOR QUANT - RA TITER $83.65 $239.00 — 65% Apr 1, 2026
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Providence Little Company of Mary Medical Center Torrance Torrance, CA · (310) 540-7676 HC RHEUMATOID FACTOR QUANTITATIVE LAB $83.65 $239.00 — 65% Apr 1, 2026
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Providence Little Company of Mary Medical Center Torrance Torrance, CA · (310) 540-7676 HC RHEUMATOID FACTOR QUANT $83.65 $239.00 — 65% Apr 1, 2026
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Saint John's Health Center Santa Monica, CA · (310) 829-5511 HC RHEUMATOID FACTOR QUANTITATIVE LAB $187.60 $536.00 — 65% Apr 1, 2026
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Saint John's Health Center Santa Monica, CA · (310) 829-5511 HC RHEUMATOID FACTOR QUANT $187.60 $536.00 — 65% Apr 1, 2026
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Inpatient: lowest $7.90, median $13.00, highest $187.60 — a 23.7× difference within the same market.

As an outpatient, the same code is billed by 28 facilities here, median $13.00 — that is the price to compare if you are not being admitted.

Cash or insurance?

At 3 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

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.

7 rows held back from this comparison

They are priced below $1 or below a tenth of the national median for code 86431 ($38.28). 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.

UCI Health - Los Alamitos Orange, CARHEUMATOID FACTOR QUANT $0.82 file
UCI Health - Fountain Valley Orange, CARHEUMATOID FACTOR QUANT $1.20 file
UCI Health - Lakewood Orange, CARHEUMATOID FACTOR QUANT $1.20 file
UCI Health - Placentia Linda Orange, CARHEUMATOID FACTOR QUANT $1.20 file
Hoag Memorial Hospital Presbyterian Newport Beach, CAHC Rheumatoid Factor Quant $1.56 file
Hoag Memorial Hospital Presbyterian Newport Beach, CAHC Rheumatoid Factor Quant - Lupus Panel 4 $2.12 file
UCI Health-Orange Orange, CAHB LAB ARUP RHEUMATOID FACTOR (UCI ONLY) $3.62 file