CPT code 86359: T-cell count, total population2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Reports a laboratory count of the total T-lymphocyte population, commonly as part of immune-status evaluation or lymphocyte subset testing.
Medicare pays $37.73 for 86359 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 86359 covers
86359 reports the total T-lymphocyte population, not a specific T-cell subset. Clinical laboratories commonly perform T-cell immunophenotyping by flow cytometry on peripheral blood. Clinicians may order the test as part of an immune-status evaluation or lymphocyte subset assessment. The result represents total T cells and differs from testing that reports an absolute T-cell count or a count/ratio.
Report 86359 for a total T-cell count, not an absolute T-cell count or a T-cell count/ratio. Medicare pays the test through the CLFS at one national amount across states and localities, with no office-versus-facility payment difference. The 2026 national CLFS amount is $37.73, unchanged from 2020 through 2026. The test is paid only through the CLFS and is excluded from the physician fee schedule.
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 86359
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 86359. 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 86359 with status X (excluded by statute), so the test itself is paid only from the CLFS.
86359 on the lab fee schedule since 2020
86359 · 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.
86359 compared with similar tests
- 86355B-cell countB lymphocytes, total$37.73
- 86355 counts B cells. Choose 86359 when the test reports the total T-cell population.
- 86357NK cell countTotal cell count$37.73
- 86357 counts natural killer cells, not T cells.
- 86360T-cell countCD4, CD8, and ratio$46.98
- 86360 identifies a T-cell absolute count/ratio; 86359 reports the total T-cell population.
- 86361CD4 countAbsolute count only$26.78
- 86361 identifies an absolute T-cell count, whereas 86359 reports the total T-cell population.
86359 billing questions
When should 86359 be used instead of 86360?
Use 86359 for the total T-cell population. Code 86360 identifies a T-cell absolute count/ratio.
Is 86359 an absolute T-cell count?
No. It reports the total T-cell population; 86361 identifies an absolute T-cell count.
What specimen and method are commonly used?
Peripheral blood is commonly tested using flow-cytometric immunophenotyping to identify and count T cells.
How does Medicare pay for 86359?
Medicare pays the test through the CLFS at a nationally priced amount that applies across localities, without an office-versus-facility payment difference.
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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