CPT code 86357: NK cell count, total cell count2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Measures the total number of natural killer cells in a specimen, supporting evaluation or monitoring of immune-cell populations.
Medicare pays $37.73 for 86357 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
$37.73
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 86357 covers
This laboratory test counts natural killer (NK) cells, a lymphocyte population involved in cellular immunity. It is commonly performed by flow cytometry on peripheral blood as part of an evaluation or monitoring of immune-cell populations. The result is a total cell count, not a test of NK-cell killing activity or a count of another lymphocyte subset.
Report 86357 for the NK-cell total count performed. The test is paid only under the Clinical Laboratory Fee Schedule (CLFS), with one national amount across states and localities and no office-versus-facility payment difference. The 2026 national CLFS amount is $37.73, unchanged since 2020. The physician fee schedule excludes this test by statute; Medicare 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 86357
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 86357. 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 86357 with status X (excluded by statute), so the test itself is paid only from the CLFS.
86357 on the lab fee schedule since 2020
86357 · CLFS 2026 Q4 (current)
$37.73
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.
86357 compared with similar tests
- 86355B-cell countB lymphocytes, total$37.73
- Use 86355 when the laboratory counts B cells. Use 86357 for the total natural killer cell count.
- 86359T-cell countTotal population$37.73
- 86359 is the total T-cell count; 86357 measures the natural killer cell population.
- 86360T-cell countCD4, CD8, and ratio$46.98
- 86360 reports a T-cell absolute count and ratio. It does not represent the NK-cell total count reported with 86357.
- 86353Lymphocyte responseMitogen- or antigen-induced$49.03
- 86353 evaluates lymphocyte transformation rather than providing a total count of natural killer cells.
86357 billing questions
How does 86357 differ from 86359?
86357 counts natural killer cells; 86359 counts T cells. Select the code for the cell population measured.
Is this an NK-cell function test?
No. It reports a total NK-cell count, not a functional response or killing assay.
What specimen is commonly used?
Peripheral blood is commonly used for NK-cell counting by flow cytometry.
How does Medicare pay 86357?
Medicare pays the test under the CLFS at one national amount, with no geographic or office-versus-facility adjustment.
Does the physician fee schedule pay separately for this test?
No. The test is excluded from the physician fee schedule by statute and is paid only under the CLFS.
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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