CPT code 83625: LDH test, isoenzyme separation and measurement2026 Medicare lab fee · Clinical Laboratory Fee Schedule
LDH isoenzyme testing separates and measures lactate dehydrogenase forms when clinicians evaluate an abnormal LDH result or its possible tissue source.
Medicare pays $12.79 for 83625 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
$12.79
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 83625 covers
Code 83625 identifies laboratory analysis that separates lactate dehydrogenase (LDH) into isoenzyme fractions and quantifies them. Unlike an assay of overall LDH activity, the fraction pattern can help clinicians evaluate an elevated LDH result and assess its possible tissue source. Clinical laboratories commonly perform this test on serum.
Report one 83625 for the LDH isoenzyme analysis; the separated fractions are part of that assay, not separate units of this code. Medicare pays 83625 under the CLFS at one national amount, with the same amount in every state and locality and no office-versus-facility difference. The 2026 national CLFS amount is $12.79, unchanged from 2020 through 2026. Medicare pays this test through the CLFS, and it is excluded from 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 83625
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 83625. 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 83625 with status X (excluded by statute), so the test itself is paid only from the CLFS.
83625 on the lab fee schedule since 2020
83625 · CLFS 2026 Q4 (current)
$12.79
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.
83625 compared with similar tests
83625 billing questions
How does 83625 differ from 83615?
83625 separates and quantifies LDH isoenzyme fractions. 83615 measures overall LDH enzyme activity.
Does 83625 measure lactic acid?
No. It measures LDH isoenzymes; 83605 is the assay for lactic acid.
What specimen is typically tested?
Serum is the typical specimen for LDH isoenzyme testing.
Are the individual isoenzymes reported as separate units of 83625?
No. The separated fractions are part of the LDH isoenzyme analysis, not separate units of 83625.
How does Medicare pay for 83625?
Medicare pays the test through the CLFS at one national amount across localities, with no office-versus-facility difference. It is excluded from the physician fee schedule.
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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