CPT code 84078: Alkaline phosphatase, heat-stable fraction2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Measures the heat-stable fraction of alkaline phosphatase; report it when this assay, rather than total alkaline phosphatase alone, is performed.
Medicare pays $8.26 for 84078 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
$8.26
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 84078 covers
This assay measures the heat-stable fraction of alkaline phosphatase activity. It is distinct from a total alkaline phosphatase measurement: 84078 represents the heat-stable assay and does not include a total test. A clinical laboratory performs and reports the result for the ordering clinician. Select the code according to the assay performed, distinguishing the heat-stable fraction from total alkaline phosphatase and from alkaline phosphatase isoenzyme testing. Report a total alkaline phosphatase test separately when that test is also performed.
Medicare pays 84078 under the Clinical Laboratory Fee Schedule. The 2026 national CLFS amount is $8.26 and has remained unchanged since 2020. The same amount applies across states and localities, without an office-versus-facility payment difference. The test 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 84078
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 84078. 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 84078 with status X (excluded by statute), so the test itself is paid only from the CLFS.
84078 on the lab fee schedule since 2020
84078 · CLFS 2026 Q4 (current)
$8.26
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.
84078 compared with similar tests
- 84075Alkaline phosphatase$5.18
- 84075 reports total alkaline phosphatase. Choose 84078 for the heat-stable enzyme activity; the total measurement is not included in 84078.
- 84080Alkaline phosphataseIsoenzyme fractions$14.78
- 84080 is used for alkaline phosphatase isoenzyme testing. Choose 84078 when the assay performed specifically measures heat-stable alkaline phosphatase activity.
- 84060Acid phosphataseTotal enzyme activity$7.64
- 84060 measures acid phosphatase, a different enzyme. It is not the code for alkaline phosphatase activity, including the heat-stable fraction.
84078 billing questions
How does 84078 differ from 84075?
84078 measures heat-stable alkaline phosphatase activity; 84075 is the code for total alkaline phosphatase. Use 84078 when the heat-stable assay is performed, not as a substitute for a total measurement.
Does 84078 include a total alkaline phosphatase test?
No. The heat-stable assay is separate from total alkaline phosphatase; report 84075 separately when that test is also performed.
When should 84078 be selected instead of 84080?
Use 84078 for the heat-stable alkaline phosphatase assay. Code 84080 describes alkaline phosphatase isoenzyme testing.
How does Medicare pay for 84078?
Medicare pays 84078 under the CLFS at one national amount that applies across localities and does not vary between office and facility settings.
Is 84078 paid under the physician fee schedule?
No. Medicare pays this test through the CLFS; 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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