CPT code 0338U: Tumor cell assay, peripheral blood, HER2 quantification2026 Medicare lab fee · Clinical Laboratory Fee Schedule
This peripheral-blood assay identifies and counts circulating solid tumor cells, including cells expressing HER2, for oncology evaluation.
Medicare pays $2,435.00 for 0338U 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
$2,435.00
In effect since Jan 1, 2026. The same amount in every state, payment locality and setting.
- Geographic adjustment
- None
- Office vs facility
- Same
- Since 2024
- 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 7 sections
What 0338U covers
This proprietary laboratory analysis evaluates circulating solid tumor cells in peripheral blood. It selects and identifies cells using EpCAM and cytokeratin 8, 18, and 19 markers, distinguishes them from CD45-expressing cells, characterizes them morphologically, and quantifies cells expressing HER2. Oncology clinicians may use the findings as part of solid-tumor evaluation. The assay is performed and reported by a clinical laboratory.
Report 0338U for this circulating-cell analysis. Medicare pays the code under the CLFS at one national rate applicable across states and localities, without an office-versus-facility difference. The 2026 national CLFS amount is $2,435.00, unchanged from 2024. The code is 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 0338U
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 0338U. 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.
Not on the physician fee schedule
The physician fee schedule doesn’t list 0338U: Medicare pays the test only from the CLFS.
0338U on the lab fee schedule since 2022
0338U · CLFS 2026 Q4 (current)
$2,435.00
Unchanged since Jan 1, 2024
Every change on file
- Jan 1, 2024 · CLFS 2024 Q1MAC-priced → $2,435.00
17 quarterly CLFS releases on file, first CLFS 2022 Q4. A code missing from a quarter wasn’t on that release.
0338U compared with similar tests
- 0332UImmunotherapy response profileEight epigenetic markers$1,142.06
- 0332U is an oncology tumor genomic profiling assay. 0338U evaluates circulating tumor cells in peripheral blood.
- 0334UTumor sequencing84 or more genes$3,500.00
- 0334U concerns solid-organ tumor genomic analysis. 0338U characterizes circulating tumor cells in peripheral blood.
- 86300Tumor markerCA 15-3 quantitative assay$20.81
- 86300 measures the CA 15-3 tumor marker. 0338U identifies and characterizes circulating tumor cells, including HER2-expressing cells.
0338U billing questions
What specimen does this assay evaluate?
It evaluates peripheral blood for circulating solid tumor cells.
What does the assay measure?
It identifies and morphologically characterizes circulating solid tumor cells and quantifies cells expressing HER2.
How does 0338U differ from tumor genomic profiling?
0338U evaluates circulating cells in peripheral blood. Codes such as 0332U and 0334U describe tumor genomic analyses.
Is there a separate physician interpretation payment?
0338U is paid only through the CLFS, not separately through the physician fee schedule.
Does the CLFS payment vary by location or setting?
No. One national amount applies across states and localities, with no office-versus-facility 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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