Lab typing of a single HLA class I antigen from the A, B, or C group, most often used in orthopedics as the HLA-B27 test for spondyloarthritis.
- Medicare
- $0.00
- Work RVU
- 0
- Global, days
- Region
- Spine
Documentation requirements
What must appear in the operative or office note to support the claim.
Source · Editorial brief grounded in 3 cited references ↓
- Inflammatory back pain features: age at onset, morning stiffness, improvement with activity
- Enthesitis, dactylitis, uveitis, or psoriasis history
- Sacroiliac joint exam and imaging findings
- Family history of spondyloarthritis
- Diagnosis code for suspected spondyloarthritis or sacroiliitis
- Specific antigen requested on the order
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 ↓
86812 covers serologic or flow-based typing of one HLA antigen in the A, B, or C group. In spine and sports clinics this is usually the HLA-B27 test. If the lab runs B27 by a molecular method instead, the claim uses a molecular pathology code, so check the lab report before you match the code.
The classic patient is a man in his 20s or 30s with low back pain that is worse in the morning, better with activity, and wakes him in the second half of the night. Heel pain at the Achilles insertion, a sausage digit, or prior uveitis all strengthen the case. A spine surgeon or physiatrist orders B27 with a CRP and sacroiliac imaging before deciding the back pain is mechanical.
The performing lab bills it under the Clinical Laboratory Fee Schedule. Payers want to see inflammatory features in the note. Mechanical low back pain (M54.5-) as the only diagnosis is the most common reason it gets denied.
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 86812 get rejected.
Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓
- Diagnosis is mechanical low back pain only
- Lab ran molecular B27 and billed the serologic code
- Test repeated when a prior B27 result is already on file
- Billed by the ordering practice instead of the lab
- Units billed for antigens not actually typed
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 3 cited references ↓
01What CPT code is used for HLA-B27?
02Does Medicare cover HLA-B27 for back pain?
03Can HLA-B27 be repeated?
04Is 86812 billed per antigen?
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 captures the inflammatory back pain history in the patient's words, including stiffness timing and response to activity, which is the detail that separates a covered B27 test from a denied one.
See how Mira captures CPT 86812 documentation