CPT code 87420: RSV antigen, immunoassay method2026 Medicare lab fee · Clinical Laboratory Fee Schedule
An RSV antigen immunoassay detects respiratory syncytial virus and is reported when a laboratory performs qualitative or semiquantitative antigen testing.
Medicare pays $13.91 for 87420 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
$13.91
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
- $13.91
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 87420 covers
This test detects respiratory syncytial virus (RSV) antigen using an immunoassay; results may be qualitative or semiquantitative. It is reported when the performed test is RSV antigen detection rather than molecular detection. It is distinct from an RSV antigen test that uses direct optical observation.
Report the service when this immunoassay is performed. CMS lists modifier QW for the CLIA-waived version, which sites holding a CLIA certificate of waiver may perform. Medicare pays 87420 through the CLFS at one national amount across states and localities, with no geographic or office-versus-facility adjustment. The 2026 national CLFS amount is $13.91, unchanged since 2020. The test is excluded from the physician fee schedule and paid only 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 87420
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 87420. 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 87420 with status X (excluded by statute), so the test itself is paid only from the CLFS.
CLIA-waived version (QW)
CMS also lists 87420 with modifier QW, the version labs holding a CLIA certificate of waiver bill. It pays $13.91.
87420 on the lab fee schedule since 2020
87420 · CLFS 2026 Q4 (current)
$13.91
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.
87420 compared with similar tests
- 87634RSV testAmplified probe detection$70.20
- Choose 87420 for RSV antigen immunoassay; choose 87634 when the laboratory performs RSV nucleic acid amplification.
- 87807RSV assayDirect visual immunoassay$13.10
- Both detect RSV antigen, but 87807 identifies direct optical observation; 87420 describes immunoassay testing.
- 87400Influenza antigenEach type tested$14.13
- 87400 detects influenza A and B antigens. Use 87420 for an RSV antigen immunoassay.
87420 billing questions
When should 87420 be used instead of an RSV molecular test?
Use 87420 when the performed test detects RSV antigen by immunoassay. An RSV nucleic acid amplification test is reported with 87634.
How does 87420 differ from 87807?
Both concern RSV antigen detection, but 87420 describes immunoassay testing generally, while 87807 is for direct optical observation.
When is modifier QW appropriate?
Append QW for the listed CLIA-waived version when the testing site holds a CLIA certificate of waiver.
What method and result format does 87420 represent?
It represents RSV antigen detection by immunoassay, with qualitative or semiquantitative results.
Does Medicare pay 87420 differently in an office and a facility?
No. Medicare pays one national CLFS amount across localities, with no office-versus-facility adjustment.
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 87420 and the rest of your codes on one sheet
Your codes at your locality, with payer contracts beside Medicare.
Build my fee sheet