CPT code 81508: Prenatal Risk Assay, two Serum Proteins2026 Medicare lab fee · Clinical Laboratory Fee Schedule
This assay measures PAPP-A and hCG in maternal serum and combines the results in an algorithmic risk score for fetal congenital abnormalities.
Medicare pays $54.30 for 81508 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
$54.30
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 81508 covers
81508 identifies biochemical assays of PAPP-A and hCG, in any form, in maternal serum, combined by an algorithm that reports a risk score for fetal congenital abnormalities. It is the two-protein version of this assay series; nearby codes distinguish other protein or analyte counts, while 81507 addresses fetal aneuploidy risk.
Report 81508 for the two-protein assay and its algorithmic risk-score result. Medicare pays the service through the CLFS at one national amount per code. The 2026 national amount is $54.30, unchanged since 2020, and is the same across states and localities, without an office or facility difference. The test is excluded from the physician fee schedule and is paid only through the CLFS.
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 81508
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 81508. 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 81508 with status X (excluded by statute), so the test itself is paid only from the CLFS.
81508 on the lab fee schedule since 2020
81508 · CLFS 2026 Q4 (current)
$54.30
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.
81508 compared with similar tests
- 81509Prenatal screenThree-protein algorithm$1,487.37
- Use 81508 for the PAPP-A and hCG two-protein assay. 81509 identifies the three-protein fetal congenital-abnormality assay.
- 81510Triple screenAFP, uE3, and hCG$55.54
- 81508 identifies the two-protein PAPP-A and hCG assay; 81510 identifies a three-analyte fetal congenital-abnormality assay.
- 81507Trisomy screeningTrisomies 21, 18, and 13$795.00
- 81508 reports a risk score for fetal congenital abnormalities from two maternal-serum proteins. 81507 is for fetal aneuploidy risk.
81508 billing questions
How does 81508 differ from 81509?
81508 identifies the PAPP-A and hCG two-protein assay. 81509 is the three-protein fetal congenital-abnormality assay.
What does 81508 report?
It reports the two-protein biochemical assay in maternal serum and an algorithmic risk score for fetal congenital abnormalities.
Is 81508 a fetal aneuploidy risk assay?
No. 81508 reports a risk score for fetal congenital abnormalities; 81507 is the nearby code for fetal aneuploidy risk.
How does Medicare pay for 81508?
Medicare pays it through the CLFS at one national amount per code, with no geographic or office-versus-facility adjustment.
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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