Blood test for antibodies against voltage-gated calcium channels, reported once for each antibody type tested, used mainly to look for Lambert-Eaton myasthenic syndrome.
- 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 ↓
- Pattern of weakness and which muscle groups are affected
- Reflex findings and any autonomic symptoms
- Imaging or exam results that rule out a structural cause
- Number and type of channel antibodies ordered
- Diagnosis code describing the neuromuscular concern
- Referral or consult plan with neurology
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 ↓
86596 reports a voltage-gated calcium channel antibody test, one unit per antibody. The main use is confirming Lambert-Eaton myasthenic syndrome, an autoimmune condition that causes proximal muscle weakness and is often linked to small cell lung cancer.
An orthopedic or sports medicine clinic sees these patients before anyone has a diagnosis. The story is hip girdle or shoulder girdle weakness, trouble rising from a chair, and normal imaging. A sharp provider sends the patient to neurology, and neurology usually orders this antibody. When an ortho practice does order it, the note should say why weakness is not explained by the joint or spine findings.
Count units carefully. If the lab tests P/Q-type and N-type antibodies, that is two units. The lab bills it under the Clinical Laboratory Fee Schedule. Most denials come from units that do not match the lab report or from a diagnosis code that does not point to a neuromuscular question.
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 86596 get rejected.
Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓
- Units billed do not match the number of antibodies reported
- Diagnosis code is a joint or spine condition with no neuromuscular link
- Ordered by a specialty the payer does not expect for this test
- Billed by the ordering practice instead of the lab
- No documented weakness pattern supporting the order
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 3 cited references ↓
01How many units of 86596 should be billed?
02What diagnosis supports CPT 86596?
03Why would an orthopedic patient need a calcium channel antibody 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 documents the strength exam and the provider's reasoning that the weakness does not fit the orthopedic findings, which is what supports a specialty lab order like this one.
See how Mira captures CPT 86596 documentation