Blood test separating creatine kinase into its isoenzyme fractions to help identify whether elevated CK comes from muscle, heart, or brain tissue.
- Medicare
- $0.00
- Work RVU
- 0
- Global, days
- Region
- General
Documentation requirements
What must appear in the operative or office note to support the claim.
Source · Editorial brief grounded in 2 cited references ↓
- Elevated or suspected elevated CK with unclear source
- Clinical scenario, such as trauma with chest symptoms
- Reason isoenzymes add information beyond troponin or total CK
- Order for both tests if 82550 also billed
- Plan based on the result
Applicable modifiers
Modifiers commonly billed with this code.
Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual
What this code covers
Source · Editorial summary grounded in 2 cited references ↓
82552 breaks total CK into its isoenzymes (MM, MB, BB). It is used when the source of an elevated CK is unclear. In orthopedic patients that usually means a trauma or post-op patient with high CK where the team needs to tell skeletal muscle injury apart from a cardiac event.
In practice, troponin has replaced CK isoenzymes for most cardiac questions, so 82552 is less common than it used to be and payers sometimes question it. If it is ordered, the note should explain why the isoenzyme split adds information. A patient with a large crush injury and chest pain is a reasonable example.
It can be billed with total CK (82550) when both are run, since the isoenzyme study is a separate test, but some payers question the pairing. Documentation needs to show both were ordered for a reason. The lab bills it under the Clinical Laboratory Fee Schedule.
RVU & reimbursement
Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.
Source · CMS Physician Fee Schedule, RVU26A · January 2026
| Work RVU | 0 |
| Practice expense RVU | 0 |
| Malpractice RVU | 0 |
| Total RVU | 0 |
| Medicare national rate | $0.00 |
| Global period | days |
Payment by site of service
Medicare pays different rates by setting. HOPD typically pays substantially more than ASC for the same procedure.
Source · CMS OPPS Addendum B·ASC HCPCS payment rates·2026
| Setting | Medicare rate (national) |
|---|---|
Office (PFS non-facility) Procedure performed in physician's office | $0.00 |
Common denial reasons
The recurring reasons claims for CPT 82552 get rejected.
Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓
- No documented reason for isoenzyme separation
- Ordered when troponin would answer the cardiac question
- Billed with 82550 without supporting documentation
- Same-day repeat without modifier 91
- Screening diagnosis
Frequently asked questions
Source · Generated from the editorial pipeline, verified against 2 cited references ↓
01When is CK isoenzyme testing used?
02Can 82550 and 82552 be billed together?
03Has troponin replaced CK-MB?
Sources & references
Editorial content was developed using the following public sources.
- 01CMS Physician Fee Schedule 2026
- 02cms.govhttps://www.cms.gov/medicare/payment/fee-schedules/clinical-laboratory-fee-schedule-clfs
Mira Scribe
Mira Scribe records the injury pattern and any cardiac symptoms in the note, which shows why the source of an elevated CK needs to be sorted out.
See how Mira captures CPT 82552 documentation