CPT code 0177U: PIK3CA test, plasma, 11 variants2026 Medicare lab fee · Clinical Laboratory Fee Schedule
This plasma DNA assay examines 11 PIK3CA variants in breast cancer and reports mutation status for molecular assessment.
Medicare pays $274.83 for 0177U 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
$274.83
In effect since Jan 1, 2026. The same amount in every state, payment locality and setting.
- Geographic adjustment
- None
- Office vs facility
- Same
- Since 2021
- 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 0177U covers
This molecular laboratory assay examines plasma DNA for 11 variants in PIK3CA, a gene analyzed in breast cancer. The result reports PIK3CA mutation status. Clinicians order it for molecular assessment of breast cancer, and a clinical molecular laboratory performs the analysis and reports the result to the ordering clinician.
Report 0177U for the plasma-based PIK3CA assay; it is distinct from tests of other genes or broader tumor panels. The analysis reports mutation status rather than a broad multigene profile. Medicare pays it through the CLFS at one national amount per code, with no locality or office-versus-facility adjustment. The 2026 national CLFS amount is $274.83, unchanged from 2021 through 2026.
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 0177U
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 0177U. 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 0177U: Medicare pays the test only from the CLFS.
0177U on the lab fee schedule since 2020
0177U · CLFS 2026 Q4 (current)
$274.83
Unchanged since Jan 1, 2021
Every change on file
- Jan 1, 2021 · CLFS 2021 Q1MAC-priced → $274.83
26 quarterly CLFS releases on file, first CLFS 2020 Q3. A code missing from a quarter wasn’t on that release.
0177U compared with similar tests
- 81309PIK3CA testTargeted sequence analysis$274.83
- Both address PIK3CA testing, but 0177U identifies the specified plasma assay for 11 variants. Code 81309 is a separate gene-analysis service; code to the assay performed.
- 0172UTumor gene assayBRCA1/2 and genomic instability$3,030.00
- This is a breast cancer test focused on BRCA1 and BRCA2, not the plasma PIK3CA mutation analysis described by 0177U.
- 0174UTumor protein assay30 targets by mass spectrometry$1,305.37
- This code describes a solid-tumor assay involving protein targets; 0177U analyzes plasma DNA for PIK3CA variants.
0177U billing questions
What specimen and result does 0177U describe?
It analyzes plasma DNA for 11 PIK3CA variants and reports PIK3CA mutation status.
How does 0177U differ from 81309?
Both concern PIK3CA, but 0177U identifies the defined plasma assay covering 11 variants. Code 81309 is another PIK3CA gene-analysis code; choose based on the assay performed.
Is 0177U a broad breast cancer gene panel?
No. It is a focused analysis of PIK3CA variants, not a multigene panel or a test of other breast cancer genes.
Does Medicare pay 0177U under the physician fee schedule?
Medicare pays this code through the CLFS.
Does payment vary by locality or place of service?
No. The CLFS amount is national for the code, without a locality or 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
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