CPT code 87451: Antigen detection, multiple organisms, polyvalent2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Reports qualitative or semiquantitative immunoassay detection of antigens from multiple infectious organisms using polyvalent antiserum.
Medicare pays $10.51 for 87451 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
$10.51
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 87451 covers
This laboratory service uses an immunoassay to detect infectious-agent antigens across multiple organisms with polyvalent antiserum. Results may be qualitative or semiquantitative. Immunoassay methods in this group include enzyme-based, fluorescence-based, and immunochemiluminometric approaches. Select 87451 when the test uses polyvalent antiserum for multiple organisms rather than an assay directed to one named pathogen. The reported finding is antigen detection by the immunoassay.
Report one unit for each polyvalent antiserum tested. Medicare pays 87451 through the CLFS, and the test is excluded from the physician fee schedule. The 2026 national CLFS amount is $10.51, unchanged from 2020 through 2026. This single amount applies in every state and locality, with no geographic or office-versus-facility adjustment.
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 87451
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 87451. 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 87451 with status X (excluded by statute), so the test itself is paid only from the CLFS.
87451 on the lab fee schedule since 2020
87451 · CLFS 2026 Q4 (current)
$10.51
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.
87451 compared with similar tests
- 87449Other antigen testEach organism, unspecified target$11.98
- 87451 is for polyvalent antiserum detecting multiple organisms. 87449 is for antigen detection of an organism not otherwise specified.
- 87426Coronavirus antigenQualitative or semiquantitative$35.33
- 87426 identifies a SARS-CoV antigen assay. Use 87451 for a polyvalent assay directed at multiple organisms instead.
- 87428Respiratory antigen testSARS-CoV-2 and influenza A/B$70.29
- 87428 is an antigen test for SARS-CoV and influenza A and B. 87451 describes polyvalent antigen detection across multiple organisms.
87451 billing questions
How is 87451 different from 87449?
Use 87451 when the immunoassay uses polyvalent antiserum to detect multiple organisms. Code 87449 describes antigen detection for an organism not otherwise specified.
How many units should be reported?
Report one unit for each polyvalent antiserum tested, consistent with the assay performed.
What should the laboratory documentation identify?
Document the immunoassay, its qualitative or semiquantitative result, and its use of polyvalent antiserum for multiple organisms.
How does Medicare pay 87451?
Medicare pays the test through the CLFS at one national amount, applied across localities without an office or facility adjustment. The code is excluded from the physician fee schedule.
When should a pathogen-specific antigen code be used instead?
Use a pathogen-specific code when the test is directed to a named organism, such as respiratory syncytial virus, SARS-CoV, or group A streptococcus, rather than a polyvalent assay for multiple organisms.
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
Fee sheets
Put 87451 and the rest of your codes on one sheet
Your codes at your locality, with payer contracts beside Medicare.
Build my fee sheet