Quantitative measurement of a specific non-antibody substance by radioimmunoassay, used when no more specific analyte code describes the test being run.
- Medicare
- $0.00
- Work RVU
- 0
- Global, days
- Region
- General
Documentation requirements
What must appear in the operative or office note to support the claim.
Source · Editorial brief grounded in 3 cited references ↓
- Signed order naming the specific analyte, not just the method
- Diagnosis supporting why the analyte was measured
- Lab report showing RIA methodology and a quantitative result
- Confirmation that no analyte-specific CPT or PLA code applies
- ABN on file for Medicare if coverage is uncertain
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 ↓
83519 is a method-based catch-all. It reports a quantitative radioimmunoassay for a substance that is not an antibody and that has no dedicated CPT code of its own. Most orthopedic offices never run RIA in house, so this code usually shows up on a reference lab's claim rather than yours.
Where ortho practices run into it is during specialty workups: metabolic bone disease, unusual hormone levels during a nonunion workup, or a send-out ordered by a co-managing endocrinologist. If your practice bills the global lab service through a purchased-service arrangement, you need the lab's method on paper before picking 83519 over 83520.
The common mistake is using 83519 when a specific analyte code exists. Payers deny or recode it when the analyte has its own code or a PLA (U) code. Labs are paid off the Clinical Laboratory Fee Schedule, not the physician fee schedule, so the 0.00 PFS values here are expected. Medical necessity rides entirely on the diagnosis code linked to the order.
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 83519 get rejected.
Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓
- A specific analyte code exists and should have been billed
- Diagnosis does not support medical necessity for the analyte
- Method on the report is not radioimmunoassay
- Billed by the ordering practice when the reference lab already billed
- Missing ABN for a test Medicare considers screening
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 3 cited references ↓
01When should I use 83519 instead of 83520?
02Can an orthopedic office bill 83519 for a send-out test?
03Why does 83519 show no Medicare payment on the physician fee schedule?
Sources & references
Editorial content was developed using the following public sources.
Mira Scribe
Mira Scribe records which analyte was ordered and the clinical reason in the plan, so the order and diagnosis line up when the lab result comes back.
See how Mira captures CPT 83519 documentation