CPT code 88280: Karyotype study, additional study2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Reports an additional karyotype study alongside the primary chromosome analysis when more than one karyotype study is performed.
Medicare pays $33.47 for 88280 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
$33.47
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 88280 covers
88280 reports an additional karyotype study within chromosome analysis. It is used in addition to the applicable primary chromosome-analysis service when another karyotype study is performed. It is distinct from a primary chromosome-analysis code and from an additional chromosome count, because the reported service is another karyotype study rather than an added count. The code identifies the additional study itself, not a separate interpretation-and-report service. Report the number of additional studies performed, rather than counting chromosomes or cells.
Report one unit for each additional karyotype study. Medicare pays 88280 only through the CLFS; the 2026 national amount is $33.47, unchanged since 2020. The same amount applies in every locality, with no geographic or office-versus-facility adjustment. Modifier 26 is not appropriate because the code is paid through the CLFS rather than 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 88280
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 88280. 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 88280 with status X (excluded by statute), so the test itself is paid only from the CLFS.
88280 on the lab fee schedule since 2020
88280 · CLFS 2026 Q4 (current)
$33.47
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.
88280 compared with similar tests
- 88262Chromosome analysis15–20 cells, two karyotypes$125.49
- 88262 identifies a primary chromosome analysis; 88280 reports an additional karyotype study associated with chromosome analysis.
- 88264Chromosome analysis20-25 cells$144.61
- 88264 identifies a primary chromosome analysis; use 88280 for an additional karyotype study, not as a substitute for the primary service.
- 88285Chromosome countAdditional cells per study$26.91
- 88285 identifies an additional chromosome count. 88280 reports an additional karyotype study.
- 88291Cytogenetic reportInterpretation and report$30.58–$42.28
- 88291 identifies a cytogenetics interpretation and report; 88280 reports an additional karyotype study.
88280 billing questions
When should 88280 be reported instead of a primary chromosome-analysis code?
Report 88280 for an additional karyotype study with the applicable primary chromosome-analysis service. It does not replace the primary service.
How many units of 88280 should be billed?
Report one unit for each additional karyotype study. Do not base the units on chromosome or cell counts.
Is modifier 26 appropriate for 88280?
No. Medicare pays 88280 through the CLFS rather than the physician fee schedule.
How is 88280 different from 88285?
88280 reports an additional karyotype study; 88285 identifies an additional chromosome count. Select the code that matches the service performed.
Does Medicare pay a different amount by locality or setting?
No. The same national CLFS amount applies across localities, with no geographic 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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