CPT code 83519: Radioimmunoassay, quantitative measurement2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Quantitative radioimmunoassay measures an analyte other than an infectious-agent antibody or antigen when the laboratory performs the test using RIA.
Medicare pays $18.40 for 83519 under the 2026 Clinical Laboratory Fee Schedule: one national amount, the same in every state and setting.
Medicare lab fee · CLFS 2026 Q4
National CLFS amount
$18.40
In effect since Jan 1, 2026. The same amount in every state, payment locality and setting.
- Geographic adjustment
- None
- Office vs facility
- Same
- Since 2020
- Unchanged
- CMS updates
- Quarterly
Medicare pays the lesser of the lab’s charge and this amount. Patients usually owe no Part B deductible or coinsurance for covered clinical lab tests.
On this page 8 sections
What 83519 covers
CPT 83519 identifies quantitative measurement of an analyte other than an infectious-agent antibody or antigen by radioimmunoassay (RIA). A clinical laboratory reports it when the performed assay uses RIA; the code is defined by the assay method and quantitative measurement, not by a named analyte or specialty. The laboratory record should identify the analyte measured and the RIA method performed.
Report the assay performed. Medicare pays 83519 only through the Clinical Laboratory Fee Schedule (CLFS). The 2026 national CLFS amount is $18.40 and has remained unchanged since 2020. CMS sets one amount for all states and localities, with no geographic adjustment or office-versus-facility difference. The code is excluded from the physician fee schedule, so payment is through the CLFS.
This summary was written with AI assistance from CMS Clinical Laboratory Fee Schedule data. Amounts on this page come directly from CMS files.
How Medicare pays 83519
Clinical lab tests aren’t priced like physician services. They’re paid from their own fee schedule, with its own rules. See the whole lab fee schedule.
One national amount
CMS sets a single Clinical Laboratory Fee Schedule amount for 83519. There’s no geographic (GPCI) adjustment, so it pays the same in every state and payment locality.
No office or facility rate
Lab tests aren’t built from relative value units, so there’s no office and facility split: the place of service doesn’t change the CLFS amount.
Updated every quarter
CMS republishes the CLFS each quarter. New tests, often proprietary laboratory analyses (PLA codes), join during the year; existing amounts are updated each January.
Excluded from the physician fee schedule
The physician fee schedule lists 83519 with status X (excluded by statute), so the test itself is paid only from the CLFS.
83519 on the lab fee schedule since 2020
83519 · CLFS 2026 Q4 (current)
$18.40
Unchanged since Jan 1, 2020
27 quarterly CLFS releases on file, first CLFS 2020 Q1. A code missing from a quarter wasn’t on that release.
83519 compared with similar tests
- 83516ImmunoassayMultiple-step, qualitative or semiquantitative$11.53
- 83516 is for a qualitative or semiquantitative immunoassay; 83519 is for a quantitative assay specifically performed by RIA.
- 83518ImmunoassaySingle-step, noninfectious analyte$9.64
- 83518 identifies a dipstick immunoassay with a qualitative or semiquantitative result. Use 83519 for a quantitative RIA.
- 83520Quantitative immunoassayNot otherwise specified$17.27
- Both describe quantitative immunoassays. 83519 specifies RIA, while 83520 is used when the method is not otherwise specified.
83519 billing questions
When should I report 83519 instead of 83520?
Use 83519 when the quantitative immunoassay is performed by radioimmunoassay. Code 83520 is the quantitative immunoassay option when the method is not otherwise specified.
How does 83519 differ from 83516?
83519 is for a quantitative assay performed by RIA. 83516 is for a qualitative or semiquantitative immunoassay.
Does 83519 identify a particular analyte?
No. It identifies the quantitative RIA method, not a specific analyte; the laboratory record should identify what was measured.
Does Medicare pay 83519 through the physician fee schedule?
No. Medicare pays this test through the CLFS, using one national amount across localities and office or facility settings.
What should the laboratory record support?
Document the analyte measured and that the test was performed using radioimmunoassay.
Where this amount comes from
FeeBase reads lab amounts directly from the CMS Clinical Laboratory Fee Schedule file for the quarter: one row per code, with its payment indicator and national amount. Contractor-priced tests are labeled, never given a made-up amount. Amounts are Medicare payment limits, not a patient’s bill or a commercial rate.
CMS CLFS 2026 Q4 · effective Oct 1, 2026 through the day before Jan 1, 2027
Show the CMS file line behind this amount
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