CPT code 87400: Influenza antigen, each type tested2026 Medicare lab fee · Clinical Laboratory Fee Schedule
An immunoassay detects influenza A or B antigen, reported for each type tested when evaluating a patient for influenza.
Medicare pays $14.13 for 87400 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
$14.13
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
- QW · CLIA-waived test
- $14.13
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 87400 covers
This immunoassay detects influenza A or influenza B antigen and reports a qualitative or semiquantitative result. It is used when testing is ordered to evaluate a patient for influenza. Clinical laboratories perform the test, and the CLIA-waived version can be performed at sites holding a CLIA certificate of waiver.
Report the code for each influenza type tested. When both A and B are tested, report two units. Append modifier QW for the CLIA-waived version when applicable. Medicare pays the test only through the CLFS, not the physician fee schedule. The 2026 national CLFS amount is $14.13, the same in every locality and in office and facility settings; it has remained unchanged since 2020.
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 87400
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 87400. 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 87400 with status X (excluded by statute), so the test itself is paid only from the CLFS.
CLIA-waived version (QW)
CMS also lists 87400 with modifier QW, the version labs holding a CLIA certificate of waiver bill. It pays $14.13.
87400 on the lab fee schedule since 2020
87400 · CLFS 2026 Q4 (current)
$14.13
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.
87400 compared with similar tests
- 87428Respiratory antigen testSARS-CoV-2 and influenza A/B$70.29
- This code is for influenza A or B antigen testing; 87428 is for a combined antigen assay that also includes SARS-CoV-2.
- 87420RSV antigenImmunoassay method$13.91
- This code detects influenza A or B antigen. Code 87420 targets respiratory syncytial virus antigen.
- 87426Coronavirus antigenQualitative or semiquantitative$35.33
- This code detects influenza A or B antigen. Code 87426 targets SARS-CoV-2 antigen.
87400 billing questions
When should this code be reported instead of 87428?
Report this code for influenza A or B antigen testing. Code 87428 represents a combined antigen test for SARS-CoV-2 and influenza A and B.
How many units are reported when both influenza types are tested?
Report one unit for each type tested. When both influenza A and B are tested, report two units.
When is modifier QW appropriate?
Use QW for the CLIA-waived version when the testing site holds a CLIA certificate of waiver.
Does Medicare pay this test under the physician fee schedule?
No. Medicare pays it under the CLFS, using one national amount across localities and settings.
Can this test be reported with another respiratory antigen test?
It may be reported with a separately performed RSV or SARS-CoV-2 antigen test when both targets are tested for the patient’s respiratory illness.
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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