CDLT Advisory Panel 2026: What the CLFS Gapfill and Crosswalk Meeting Means for Labs
Short answer: The Medicare Advisory Panel on Clinical Diagnostic Laboratory Tests met September 15-16, 2026 to advise CMS on crosswalk and gapfill payment for CY 2027 codes that had no applicable market data. The panel's consent agenda covered 339 codes. CMS proposed rates follow in late September, comments in October, and final rates in November.
What the panel actually decides
Under Section 1834A of the Social Security Act, added by the Protecting Access to Medicare Act of 2014, CMS sets Clinical Laboratory Fee Schedule (CLFS) rates from private payer data. When a test has no reportable data, CMS needs another way to price it. The Federal Register notice announcing the September meeting says the panel advises on "crosswalking or gapfilling" for CY 2027 codes for which CMS "received no applicable information."
Crosswalking is used when a new test is comparable to an existing test, so it inherits that test's rate. Gapfilling is used when no comparable test exists, and Medicare Administrative Contractors (MACs) determine initial amounts using charges, resources required, and other payer information. Which basis CMS lands on can move a molecular code's rate materially, so the panel is where lab revenue for new codes starts to take shape.
The 339-code consent agenda
CMS published a consent agenda for the September 16 voting day. It groups 339 codes: 156 where the original crosswalk determination is maintained, 107 where the original gapfill is maintained, and 76 new codes requiring gapfill. A consent agenda lets the panel adopt many determinations in one motion, while any member can pull a code out for separate discussion.
The list includes many genomic codes, such as 0173U (a 14-gene psychiatric pharmacogenomic panel), 0094U (rapid genome sequence analysis) and 81188 (CSTB expanded-allele analysis). If your lab bills PLA or Tier 1 and Tier 2 molecular codes, check the CMS document for your specific codes rather than assuming they are covered by the consent motion.
Who presented, and on which molecular codes
Day 1 was public presentations of about five minutes each, and the agenda lists 38 presenting organizations. Three presenters stand out for molecular work: Mayo Clinic listed 24 codes including 81427, 81524 and 0072U-0076U; Variantyx listed 16 genomic codes including 0212U-0218U and 0230U-0238U; and the Association for Molecular Pathology (AMP) listed 10 codes, including 81172, 81188, 81190, 81195, 81274, 81289, 81313, 81337, 81346 and 81349.
The data reporting window that produced the "no applicable information" codes ran May 1 through July 31, 2026. A code with no reported private payer data is not a code with no cost; it is a code where the rate will be built from crosswalk or gapfill evidence, which makes lab-submitted cost and charge documentation decisive.
Why the pricing basis matters for molecular labs
Many advanced molecular tests are billed with PLA codes, which are frequently new and therefore more likely to lack private payer data in their first reporting cycle. That is why so many genomic codes appear on this agenda. For those tests, a gapfill rate begins with MAC-determined amounts built from charges, resources and other payer information, so the quality of the documentation a lab submits can shape the starting point.
Revenue cycle teams should also remember that a CLFS rate is a Medicare benchmark that many commercial contracts reference. A rate that lands lower than expected can ripple into contract negotiations, while a rate set through a comparable crosswalk may be more predictable. Tracking which basis CMS proposes for each of your codes is therefore a planning input, not only a compliance check.
What happens next
Per the Federal Register notice, CMS posts proposed determinations in late September 2026, the public submits written comments in October 2026, and final determinations are posted in November 2026 for the CY 2027 CLFS. CMS states it considers the comments made at the annual public meeting, held June 10, 2026, when preparing proposed determinations.
For context on how these determinations sit alongside other rate pressures, see our analysis of CLFS 2027 preliminary rates for molecular pathology and of PAMA rate cuts scheduled for 2027.
What labs and RCM teams should do now
First, pull the consent agenda and match every code you bill, especially new PLA codes, to its category. Second, when the proposed determinations post, compare the proposed rate and basis with your own cost and charge data. Third, prepare October comments early; comments that include cost data and a clear rationale for a different basis are the type the process is designed to consider. Fourth, model revenue for 2027 using the proposed rate, not the current one, until finals post in November.
Labs launching new tests should also review timing for code assignment; our guide to the PLA code application deadline and the September 2026 CPT Editorial Panel lab codes cover the coding side that feeds this pricing process. For the coverage side, see Medicare coverage for genetic testing. ScreenMyGene helps labs organize coverage and claim documentation; learn more on our homepage.
Frequently asked questions
What is the CDLT Advisory Panel?
It is the Medicare Advisory Panel on Clinical Diagnostic Laboratory Tests. It advises HHS and CMS on payment methodology for clinical laboratory tests, including whether new codes without market data should be crosswalked to existing tests or gapfilled, under Section 1834A of the Social Security Act.
What is the difference between crosswalking and gapfilling?
Crosswalking assigns a new test the rate of a comparable existing test. Gapfilling is used when no comparable test exists; MACs determine initial amounts using charges, resources required and other payer information, and CMS then finalizes national rates after public comment.
How many codes were on the September 2026 consent agenda?
CMS listed 339 codes: 156 with the original crosswalk maintained, 107 with the original gapfill maintained, and 76 new codes requiring gapfill. Panel members can request that any code be removed from the consent motion for separate discussion.
When are final CY 2027 rates for these codes set?
Per the Federal Register notice, CMS posts proposed determinations in late September 2026, accepts public comments in October, and posts final determinations in November 2026 for the CY 2027 Clinical Laboratory Fee Schedule.
Can labs still influence the outcome?
Yes. The presentation window has closed, but CMS accepts written public comments on its proposed determinations in October 2026. Comments supported by cost and charge data on the appropriate payment basis are the most useful input for the final rate.
This article is for educational purposes only and does not constitute legal, coding, reimbursement or medical advice. Payment determinations are set by CMS and may change; verify against current CMS publications.
Sources: Federal Register, Medicare Program: Meeting Announcement for the Medicare Advisory Panel on Clinical Diagnostic Laboratory Tests, September 2026 (2026-08513, May 1, 2026); Federal Register, Public Meeting Regarding New and Reconsidered CDLT Codes for CY 2027 CLFS (2026-08511, May 1, 2026); CMS, CDLT Panel Meeting Agenda, September 15-16, 2026; CMS, Consent Agenda Codes, CDLT Panel Meeting 9/16/2026; Section 1834A of the Social Security Act.