CPT code 84450: AST, aspartate aminotransferase2026 Medicare lab fee · Clinical Laboratory Fee Schedule
Measures AST enzyme activity in blood to evaluate possible liver injury and other causes of elevated aminotransferase levels.
Medicare pays $5.18 for 84450 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
$5.18
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
- $5.18
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 84450 covers
This blood chemistry test measures aspartate aminotransferase (AST), also called SGOT. Clinicians use the result when assessing possible liver injury, interpreting abnormal liver tests, or evaluating other conditions that can raise AST, including muscle injury. Clinical laboratories generally perform the assay on a blood specimen; the result is interpreted with the patient’s symptoms and other laboratory findings. AST is also included in common chemistry panels, so the requested service may be reported as an individual test or as part of a panel, depending on what was performed and ordered.
Report 84450 for the AST assay, not for alanine aminotransferase (ALT), which is a different test. CMS lists a QW version for sites holding a CLIA certificate of waiver. Medicare pays this test only through the CLFS. The 2026 national CLFS amount is $5.18, unchanged since 2020; the same amount applies in every locality, with no office or facility difference.
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 84450
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 84450. 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 84450 with status X (excluded by statute), so the test itself is paid only from the CLFS.
CLIA-waived version (QW)
CMS also lists 84450 with modifier QW, the version labs holding a CLIA certificate of waiver bill. It pays $5.18.
84450 on the lab fee schedule since 2020
84450 · CLFS 2026 Q4 (current)
$5.18
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.
84450 compared with similar tests
- 84460ALT testSGPT enzyme level$5.30
- Choose 84450 for AST (SGOT) and 84460 for ALT (SGPT). The tests measure different enzymes and may be ordered together.
- 80053Metabolic panelFourteen blood chemistry tests$10.56
- Use 80053 when the comprehensive metabolic panel is performed; use 84450 for an individual AST assay rather than the panel.
- 80076Liver panelSeven liver chemistry tests$8.17
- Use 80076 for a performed hepatic function panel that includes AST. Code 84450 represents the individual AST assay.
84450 billing questions
How is 84450 different from 84460?
84450 measures AST (SGOT); 84460 measures ALT (SGPT). They are distinct enzyme tests and may be ordered together.
When should a panel code be used instead?
Use the applicable panel code when the ordered and performed service is a panel that includes AST, such as a comprehensive metabolic panel or hepatic function panel. Do not substitute 84450 for a panel.
When is modifier QW appropriate?
CMS lists a QW version for the CLIA-waived test. Use it when the testing site holds a CLIA certificate of waiver and performs the waived version.
How does Medicare set payment for this test?
Medicare pays one national CLFS amount per code, with no locality adjustment or office-versus-facility difference.
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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