CPT code 81511: Prenatal screen, four-analyte risk score2026 Medicare lab fee · Clinical Laboratory Fee Schedule
A four-marker maternal-serum prenatal assay combines biochemical results in an algorithmic risk score for fetal congenital abnormalities.
Medicare pays $153.50 for 81511 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
$153.50
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 81511 covers
This maternal-serum prenatal screening assay measures AFP, unconjugated estriol (uE3), hCG in any form, and dimeric inhibin A. A laboratory algorithm combines the biochemical results into a risk score for fetal congenital abnormalities and may incorporate results from earlier biochemical testing. Obstetric clinicians use the score in prenatal risk assessment, including assessment for trisomy 21, trisomy 18, and open neural tube defects. The result estimates risk; it does not establish a fetal diagnosis.
Report one unit for the four-analyte algorithm performed, not one unit for each marker. Medicare pays 81511 only through the CLFS. Its 2026 national amount is $153.50, unchanged from 2020 through 2026, and the same amount applies across states and localities without an office or facility adjustment. The test is excluded from the physician fee schedule by statute.
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 81511
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 81511. 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 81511 with status X (excluded by statute), so the test itself is paid only from the CLFS.
81511 on the lab fee schedule since 2020
81511 · CLFS 2026 Q4 (current)
$153.50
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.
81511 compared with similar tests
- 81510Triple screenAFP, uE3, and hCG$55.54
- 81510 represents a three-analyte fetal congenital-abnormality algorithm; 81511 is for the four-analyte algorithm.
- 81512Prenatal screenFive-analyte maternal serum$69.52
- 81512 represents a five-analyte fetal congenital-abnormality algorithm. Select the code matching the algorithm performed.
- 81509Prenatal screenThree-protein algorithm$1,487.37
- 81509 is a related three-protein fetal congenital-abnormality screen; 81511 represents a four-analyte algorithm.
- 81508Prenatal Risk AssayTwo Serum Proteins$54.30
- 81508 describes a related two-protein fetal congenital-abnormality screen, rather than the four-analyte algorithm reported with 81511.
81511 billing questions
When should 81511 be selected instead of a three-analyte screen?
Use 81511 when the laboratory performs the four-analyte maternal-serum algorithm. The three-analyte code applies to a different assay configuration.
Is 81511 reported once per marker or per algorithm?
Report one unit for the combined four-analyte algorithm. Do not assign a separate unit for each marker.
Does 81511 diagnose a fetal condition?
No. It produces a risk estimate used in prenatal screening; it does not establish a fetal diagnosis.
How does Medicare pay 81511?
Medicare pays the test through the CLFS only. One national amount applies across localities, without an office or facility adjustment, and the test is excluded from the physician fee schedule by statute.
What documentation supports reporting 81511?
The laboratory record should support that a maternal-serum, four-analyte algorithm was performed and that the result was reported as a risk score.
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
Fee sheets · Coming soon
Put 81511 and the rest of your codes on one sheet
Your codes at your locality, with payer contracts beside Medicare.
Join the waitlist