CMS Clinical Laboratory Fee Schedule (CLFS) Annual Public Meeting

Section 1833(h)(8) of the Social Security Act (the Act), as amended by Section 531(b) of the Medicare, Medicaid, and SCHIP Benefits Improvement and Protection Act of 2000 (BIPA) requires the Secretary to establish through regulations, procedures that permit public consultation for payment determinations for new clinical diagnostic laboratory tests under Medicare Part B.  Section 1834A(f) of the Act requires consultation with an expert outside advisory panel on such payment determinations. These procedures are set forth in 42 C.F.R. § 414.506 (for a quick reference resource, please refer to the Clinical Laboratory Fee Schedule Annual Payment Determination Process MLN Education Tool; MLN-9034855).

What occurs during the CLFS Annual Public Meeting?

The CLFS Annual Public Meeting provides an opportunity for the public to present comments and recommendations (including accompanying data on which recommendations are based) on the appropriate basis for establishing payment amounts for new or substantially revised Healthcare Common Procedure Coding System (HCPCS) codes being considered for Medicare payment under the CLFS for the next calendar year (CY).

This meeting also provides a forum for the public to provide comments on certain reconsideration requests submitted during the previous year regarding final determinations on new and substantially revised test codes. For example, the public may provide comments on reconsideration requests regarding the basis of payment (crosswalk or gapfill) and the amount of payment determined for those new and or substantially revised test codes in which crosswalking was used as the basis of payment for the test. During the meeting, we allow opportunity for an open forum where questions may be posed to presenters from those in the audience and members of the Advisory Panel on Clinical Diagnostic Laboratory Tests (the CDLT Panel).

What occurs after the CLFS Annual Public Meeting?

Preliminary Determinations

Following the CLFS Annual Public Meeting, the CDLT Panel convenes (usually the following month) and provides recommendation for the basis of payment (either crosswalked or gapfilled) for each new or reconsidered laboratory test (please refer to the CDLT Advisory Panel website for more information on the CDLT Advisory Panel);

  • Crosswalking occurs when a new test or substantially revised test is determined to be similar to an existing test, multiple existing test codes, or a portion of an existing test code, which can then be utilized to determine a payment.
  • Gapfilling occurs when no comparable, existing test is available. In this case, the MACs develop a local payment amount for the new test code and CMS calculates an NLA after a year of payment at the local MAC rates based on the median of rates for the test code across all MACs.

After consideration of the information from the ALM, public comments and CDLT Advisory Panel recommendations, we generally post preliminary payment determinations on our website in September of each year.

Unlike a new crosswalked test, the payment amount for a new gapfilled test is not established when we determine the basis for payment because it takes approximately 9 months from the CLFS Annual Public Meeting for MACs to establish MAC-specific amounts and report those amounts to CMS.

Final Determinations

In November of each year, CMS finalizes the basis of payment for new and substantially revised test codes and the amount of payment through the annual CMS instruction implementing the updated CLFS for the next CY.


The public has an additional 60 days from the date we issue our annual instruction to request reconsideration of either the basis of payment (gapfill or crosswalk) or the amount of payment (if crosswalking is used as the basis of payment) for new and or substantially revised test codes. The public may comment on these reconsideration requests at the next CLFS Annual  Public Meeting.

Gapfilling Schedule

For any new test code that will be gapfilled, we request our MACs to develop MAC-specific gapfilled amounts for each test code and report the amount to CMS by April 1 of the following year. Example: At the July 2016 Annual CLFS Public Meeting, gapfilling is recommended as the basis of payment for a given new test code and that recommendation is finalized November 2016. In this case, the MACs have until April 1, 2017 to develop and report a preliminary gapfilled payment amount for the new test code.

Once gapfilled prices for tests are developed by the MACs and reported to CMS, we post prices on our website and accept public comments on the gapfilled amounts for 60 days (not reconsideration requests, just comments).

Once we post the final MAC-specific gapfilled amounts to our website, we accept reconsideration requests on the final gapfilled payment amounts for new and substantially revised test codes for 30 days. However, once the reconsideration process ends for a gapfilling cycle, the gapfilled payment amount is final and not subject to further reconsideration.

CMS implements an NLA after a year of payment at the local MAC-specific gapfilled amounts based on the median of final gapfilled rates for the test code across all MACs. For example, MAC-specific gapfilled amounts finalized in November 2017 would be used to establish an NLA for the test and the NLA would be effective for the CY 2018 CLFS.

Final Medicare Administrative Contractor Gapfill payment recommendations have been posted below. We invite reconsideration requests through November 4, 2022. Please submit comments to

Meeting Notice, Agenda, and Other Important Materials

We publish a notice of upcoming meetings in the Federal Register and post the meeting agenda on this webpage.

Payment Determinations

Gapfilling Determinations

Test Code Updates


Page Last Modified:
11/28/2022 04:01 PM