CPT code 86355: B-cell count, B lymphocytes, total2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Laboratory measurement of total B cells, a white blood cell population, reported when the test counts B cells rather than another lymphocyte population.
Medicare pays $37.73 for 86355 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 86355 covers
Code 86355 reports a laboratory measurement of the total number of B cells, a white blood cell population. It identifies the B-cell count and distinguishes it from tests that count T cells or natural killer cells. Laboratories report this code when the service performed measures total B cells; it should not be used to represent a different lymphocyte population.
Medicare pays 86355 only through the CLFS. CMS sets one national amount that applies in every state and locality, with no geographic adjustment or office-versus-facility payment difference. The 2026 national CLFS amount is $37.73, unchanged from 2020 through 2025. The service is excluded from the physician fee schedule by statute. Payment is one amount per code rather than a locality-specific amount.
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 86355
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 86355. 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 86355 with status X (excluded by statute), so the test itself is paid only from the CLFS.
86355 on the lab fee schedule since 2020
86355 · 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.
86355 compared with similar tests
- 86357NK cell countTotal cell count$37.73
- Use 86357 for a natural killer cell count. Code 86355 counts B cells.
- 86359T-cell countTotal population$37.73
- Use 86359 for total T-cell counting. Code 86355 is specific to B cells.
- 86360T-cell countCD4, CD8, and ratio$46.98
- Code 86360 reports a T-cell absolute count and ratio; 86355 reports a B-cell count.
- 86361CD4 countAbsolute count only$26.78
- Code 86361 is for an absolute T-cell count. Select 86355 when the measured population is B cells.
86355 billing questions
What does 86355 count?
It reports the total count of B cells, a white blood cell population.
How does 86355 differ from 86357?
Code 86355 is for B cells; 86357 is for natural killer cells. Select the code for the population counted.
How does 86355 differ from 86359?
Code 86355 counts B cells, while 86359 counts total T cells.
Which Medicare fee schedule pays 86355?
Medicare pays 86355 only through the CLFS. One national amount applies across localities and office and facility settings.
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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