CPT code 80170: Gentamicin assay, therapeutic drug monitoring2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Measures gentamicin concentration to monitor exposure and guide dose adjustment during treatment, with collection timing interpreted alongside dosing history.
Medicare pays $16.38 for 80170 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
$16.38
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 80170 covers
Assay 80170 measures gentamicin concentration, generally in serum, for patients receiving systemic gentamicin therapy. Clinicians use measured levels to assess exposure and guide dosing, particularly when renal function changes or drug accumulation is a concern. Peak and trough interpretation depends on when the specimen was collected in relation to a dose; the ordering clinician considers collection time alongside dosing history and clinical status. Hospital and reference laboratories perform or report this testing for antimicrobial treatment monitoring.
Report 80170 for gentamicin testing; it does not distinguish peak from trough collection. Medicare pays the test under the CLFS, with one national amount per code and no locality or office/facility adjustment. The 2026 national CLFS amount is $16.38, unchanged since 2020. The test is excluded from the physician fee schedule and 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 80170
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 80170. 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 80170 with status X (excluded by statute), so the test itself is paid only from the CLFS.
80170 on the lab fee schedule since 2020
80170 · CLFS 2026 Q4 (current)
$16.38
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.
80170 compared with similar tests
- 80150Amikacin levelTherapeutic drug monitoring$15.08
- 80150 is for an amikacin assay. Choose 80170 when the measured drug is gentamicin.
- 80200Tobramycin levelAntibiotic monitoring$16.13
- 80200 measures tobramycin, not gentamicin. Select the code that matches the antibiotic tested.
- 80202Vancomycin levelAntibiotic concentration$13.54
- 80202 is for a vancomycin assay. It is not interchangeable with the gentamicin assay reported under 80170.
80170 billing questions
Does 80170 distinguish peak and trough gentamicin levels?
No. The code identifies the gentamicin assay, not the collection timing. Record the specimen collection time relative to the dose so the result can be interpreted in context.
Should 80170 be used for another aminoglycoside level?
No. Use 80170 for gentamicin; amikacin and tobramycin assays have separate codes.
Does Medicare pay 80170 under the physician fee schedule?
No. Medicare pays this test through the CLFS; it is excluded from the physician fee schedule.
Does the CLFS amount vary by locality or setting?
No. Medicare pays one national amount for 80170, without a locality or office/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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