CPT code 81311: NRAS variant test, exons 2 and 32026 Medicare lab fee · Clinical Laboratory Fee Schedule
NRAS exon 2 and 3 variant analysis supports cancer testing, including colorectal carcinoma assessment, and is reported for testing these gene regions.
Medicare pays $295.79 for 81311 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
$295.79
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 81311 covers
This molecular pathology test evaluates NRAS gene variants in exons 2 and 3, including codons 12 and 13 in exon 2 and codon 61 in exon 3. It supports cancer testing, including colorectal carcinoma assessment. The analysis covers these NRAS regions and is distinct from testing other genes such as KRAS or BRAF, or from microsatellite instability testing.
Report 81311 for analysis of the specified NRAS regions. The named codons are examples of variant locations within those regions, not separate tests. Medicare pays the test only through the CLFS. The 2026 national CLFS amount is $295.79, unchanged since 2020, and the same amount applies in every state and locality, with no office-versus-facility payment difference. The test has no separate physician fee schedule payment.
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 81311
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 81311. 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 81311 with status X (excluded by statute), so the test itself is paid only from the CLFS.
81311 on the lab fee schedule since 2020
81311 · CLFS 2026 Q4 (current)
$295.79
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.
81311 compared with similar tests
- 81275KRAS testingExon 2 variants$193.25
- 81311 analyzes NRAS variants in exons 2 and 3; 81275 analyzes KRAS. They assess different genes.
- 81210BRAF testV600 variant analysis$175.40
- 81311 targets NRAS exons 2 and 3, while 81210 analyzes BRAF variants.
- 81301MSI analysisMismatch repair markers$348.56
- 81311 analyzes NRAS gene variants; 81301 assesses microsatellite instability, a different molecular feature.
81311 billing questions
When should this code be chosen instead of a KRAS test?
Use 81311 for analysis of NRAS variants in exons 2 and 3. A KRAS test analyzes a different gene.
Which NRAS regions does this code cover?
It covers exons 2 and 3, including variant locations such as codons 12 and 13 in exon 2 and codon 61 in exon 3.
Does this code include testing for other tumor markers?
No. It represents NRAS analysis; KRAS, BRAF, and microsatellite instability are distinct analyses.
How does Medicare pay for this test?
Medicare pays it only through the CLFS at one national amount, without locality or office-versus-facility adjustment.
Is the analysis reported separately for each codon?
The code describes NRAS analysis across the specified regions; the codons are examples of variant locations within them.
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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