# CPT 83520

> Not at a published national rate. CPT 83520 carries status X (statutory exclusion) in the Q4 2015 release. The statutory definition of physician services does not include this item. Treat the blank amount as unpriced, not as $0.

## What it is

A general-purpose laboratory code for measuring how much of a particular substance is present in a sample using an antibody-based method, when that substance has no code of its own and is not an infectious organism or an antibody to one. Quantitative means the lab reports an actual number rather than just a positive or negative. Because the code is deliberately open-ended, the laboratory has to identify on the claim what was actually measured.

## Selected release

- Release: Q4 2015 (2015 D)
- Effective: October 1 – December 31, 2015
- Status indicator: X
- Office (non-facility) national allowed amount: not published
- Facility national allowed amount: not published
- Sequestration: not applied

## RVUs and formula

- Work RVU: not published
- Office (non-facility) practice expense RVU: not published
- Facility practice expense RVU: not published
- Malpractice RVU: not published
- Conversion factor: 35.9335
- Formula: `(work_rvu × work_gpci + pe_rvu × pe_gpci + mp_rvu × mp_gpci) × conversion_factor`

## Source and citation

- Source: Physician relative value file (Q4 2015)
- CMS file: https://www.cms.gov/medicare/medicare-fee-for-service-payment/physicianfeesched/downloads/rvu15d.zip
- Parsed file: PPRRVU15_OCT05_V1001.csv, row 13,410
- Canonical page: https://localishealth.com/cpt/83520/2014/B
- Release-specific citation URL: https://localishealth.com/cpt/83520/2015/D
- Last significant update: 2026-08-04T03:06:14+00:00