CPT code 82550: Total CK, total enzyme activity2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Measures total creatine kinase activity, distinguishing it from assays that report the CK-MB fraction or CK isoforms.
Medicare pays $6.51 for 82550 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
$6.51
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
- QW · CLIA-waived test
- $6.51
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 82550 covers
This assay measures total creatine kinase (CK) activity in a blood specimen, commonly serum or plasma. CK can enter the bloodstream after muscle injury, and clinicians use total CK testing when evaluating suspected rhabdomyolysis, muscle trauma, inflammatory muscle disease, or possible medication-related muscle injury. The result represents overall CK activity; it does not identify a particular CK fraction or isoform. Clinical laboratories perform the assay and report results to the ordering clinician.
Report 82550 for total CK activity. Use a related code when the requested assay includes the MB fraction or specifically evaluates CK-MB or isoforms. Medicare pays this test under the CLFS at one national amount across localities, without an office-versus-facility difference; the 2026 national amount is $6.51, unchanged since 2020. A CLIA-waived version may be reported with modifier QW by a site holding a CLIA certificate of waiver.
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 82550
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 82550. 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 82550 with status X (excluded by statute), so the test itself is paid only from the CLFS.
CLIA-waived version (QW)
CMS also lists 82550 with modifier QW, the version labs holding a CLIA certificate of waiver bill. It pays $6.51.
82550 on the lab fee schedule since 2020
82550 · CLFS 2026 Q4 (current)
$6.51
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.
82550 compared with similar tests
- 82552CK isoenzymesBlood isoenzyme assay$13.39
- Choose 82550 for total CK activity alone; 82552 measures total CK together with the MB fraction.
- 82553CK-MB testMB fraction only$11.55
- This code reports total CK. Code 82553 measures the CK-MB fraction only.
- 82554CK isoformsIsoform analysis$11.87
- This code reports total CK activity, while 82554 analyzes CK isoforms.
82550 billing questions
When should total CK be reported instead of 82552?
Report 82550 for total CK activity alone. Code 82552 covers total CK measured with the MB fraction.
When is modifier QW appropriate?
Use QW for the CLIA-waived version when performed by a site holding a CLIA certificate of waiver.
Does Medicare pay this test under the physician fee schedule?
No. Medicare pays this test under the CLFS, at one national amount across localities and without an office-versus-facility difference.
Does total CK identify the CK-MB fraction or CK isoforms?
No. Total CK reports overall enzyme activity; use the corresponding code when the assay measures the MB fraction or CK isoforms.
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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