Lab test that measures the amount of rheumatoid factor in a blood sample, reported as a numeric value rather than a simple positive or negative result.
- Medicare
- $0.00
- Work RVU
- 0
- Global, days
- Region
- Multi-region
Documentation requirements
What must appear in the operative or office note to support the claim.
Source · Editorial brief grounded in 3 cited references ↓
- Joints involved and whether the pattern is symmetric
- Duration of morning stiffness
- Exam findings such as synovitis, effusion, or warmth
- Specific diagnosis code supporting the order, not pain alone
- Other inflammatory labs ordered at the same visit
- Ordering provider name and NPI on the requisition
Applicable modifiers
Modifiers commonly billed with this code.
Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual
What this code covers
Source · Editorial summary grounded in 3 cited references ↓
86431 is the quantitative rheumatoid factor test. The lab reports a titer or IU/mL value, not just positive or negative. The qualitative version is 86430, and the two should not be reported together on the same specimen.
Orthopedic practices order it when a patient shows up with symmetric small-joint swelling, morning stiffness that lasts more than an hour, or a knee effusion that does not fit an injury story. It often goes out with a sed rate, CRP, and anti-CCP. A positive result usually means a rheumatology referral, not a surgical plan.
This code is excluded from the physician fee schedule. Medicare pays it through the Clinical Laboratory Fee Schedule, and only the entity that runs the test bills it. If your office draws blood and sends it out, you bill the draw (36415) and the reference lab bills 86431. Denials usually trace back to a weak diagnosis code. Joint pain alone (M25.5-) gets questioned by some payers, so link the specific finding: polyarthritis, effusion, or synovitis.
RVU & reimbursement
Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.
Source · CMS Physician Fee Schedule, RVU26A · January 2026
| Work RVU | 0 |
| Practice expense RVU | 0 |
| Malpractice RVU | 0 |
| Total RVU | 0 |
| Medicare national rate | $0.00 |
| Global period | days |
Payment by site of service
Medicare pays different rates by setting. HOPD typically pays substantially more than ASC for the same procedure.
Source · CMS OPPS Addendum B·ASC HCPCS payment rates·2026
| Setting | Medicare rate (national) |
|---|---|
Office (PFS non-facility) Procedure performed in physician's office | $0.00 |
Common denial reasons
The recurring reasons claims for CPT 86431 get rejected.
Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓
- Billed by the ordering practice instead of the performing lab
- Reported with 86430 on the same specimen
- Diagnosis limited to nonspecific joint pain
- Lab not CLIA certified for the test complexity
- Repeat test billed without modifier 91 or clinical reason
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 3 cited references ↓
01What is the difference between CPT 86430 and 86431?
02Can an orthopedic office bill 86431 if it sends the blood out?
03Why is 86431 showing $0 on the Medicare physician fee schedule?
04What diagnosis codes support a rheumatoid factor test?
Sources & references
Editorial content was developed using the following public sources.
- 01CMS Physician Fee Schedule 2026
- 02CMS Clinical Laboratory Fee Schedule 2026
- 03cms.govhttps://www.cms.gov/medicare/coding-billing/national-correct-coding-initiative-ncci-edits
Mira Scribe
Mira Scribe records the joint pattern, stiffness duration, and exam findings in the provider's own words, so the order has the clinical reason a payer wants to see next to the diagnosis code.
See how Mira captures CPT 86431 documentation