What PAMA reporting does to your CLFS rates

The mechanism is a weighted median, and it is deliberately rigid

42 CFR 414.507(a) (eCFR text as of August 20, 2026, read 2026-08-25) sets the general rule:

Paragraph (b) gives the whole computation in one sentence:

Every reported final payment for a test’s HCPCS code, weighted by how many tests were paid at that rate, arrayed; the middle of that distribution is the Medicare rate. Two more provisions in the same section remove the usual softeners. Paragraph (c): the resulting amounts “are not subject to any adjustment, such as geographic, budget neutrality, annual update, or other adjustment.” Paragraph (e): “There is no administrative or judicial review under sections 1869 and 1878 of the Social Security Act, or otherwise, of the payment rates established under this subpart.”

So a lab’s lever over its future CLFS rate ended when the reporting window closed. The median is set by what the industry reported, and there is no appeal channel against the resulting number.

What this cycle’s data sets, and for how long

CMS’s PAMA FAQ (updated July 14, 2026, read 2026-08-25) states the output of the 2026 reporting cycle: “The upcoming reported data for CDLTs that are not ADLTs will be used to determine CLFS payment rates for CY 2027 through CY 2029.” Three years per cycle is the regulation’s cadence too: rates hold “for a period of one calendar year for ADLTs and three calendar years for all other CDLTs” (42 CFR 414.507(a)).

The input was the first half of 2025: Section 6226 of the Consolidated Appropriations Act, 2026 (Public Law 119-75, enacted February 3, 2026) rebased the data collection period on 2025, so the January 2027 fee schedule will price tests off private payor payments finalized between January 1, 2025 and June 30, 2025.

The caps: how fast a rate can actually fall

A weighted median can land far below a test’s current Medicare rate. The statute limits how much of that drop takes effect per year, and this is where the February 2026 change matters. Section 6226(a) of Public Law 119-75 amends section 1834A(b)(3) of the Social Security Act by striking “2028” and inserting “2029”, and rewrites the two operative clauses: the zero reduction clause now covers through “2026”, and the 15 percent clause now covers “each of 2027 through 2029”.

CMS states the combined result in its FAQ, in one sentence worth keeping:

Its reporting resources page (last modified August 3, 2026) says the near half of that even more plainly: “There's no phase-in reduction in 2026.”

Concretely, for a test already on the CLFS: its 2026 rate cannot go down at all. Its 2027 rate can be at most 15 percent under its 2026 rate, its 2028 rate at most 15 percent under 2027, and its 2029 rate at most 15 percent under 2028, even where the reported median sits lower than that floor the whole way. Over the three capped years that compounds to a maximum cut of about 38.6 percent from the 2026 rate (0.85 to the third power, our arithmetic on the capped percentages above, not a figure from any source). The caps only brake descent: nothing in 1834A(b)(3) limits a rate increase when the median comes in higher, and nothing guarantees any particular test hits the floor. The cap population is also bounded: 42 CFR 414.507(d) applies it to “each CDLT that is not a new ADLT or new CDLT”, so a brand new test priced by crosswalk or gapfill has no prior-year rate to be protected against.

The trap: the CFR on the books is one law behind

Read the eCFR today and 414.507(d) still prints the pre-February schedule: zero percent caps through 2025 and 15 percent caps for “2026”, “2027”, and “2028”. Its amendment history ends at 89 FR 98559, December 9, 2024, which predates the statute. The regulation was simply never re-amended after Section 6226 passed, and the statute itself anticipates that: Section 6226(d) provides that “the Secretary of Health and Human Services may implement the amendments made by this section by program instruction or otherwise.” No rulemaking was required for the new schedule to be the real one.

So three texts currently disagree on what happens in 2026, and they are not equal. The statute as amended (no reduction in 2026, caps through 2029) controls. CMS’s operational pages already say the same thing. Only the codified regulation still shows 15 percent for 2026, and anyone quoting the CFR raw this year will state the caps wrong by exactly one law.

What this page will not tell you

It will not tell you your rate for any specific HCPCS code in 2027: that number is the weighted median of what got reported, CMS has not published it, and nothing here predicts it. And it will not tell you whether your laboratory owed data into this median. That status is self-determined from a lab’s own revenue composition, which is the boundary this whole site is built around: the proven, suggested, and unknowable split is laid out at pamawatch.com/method.

Sources, each read this session

42 CFR 414.507, eCFR text as of August 20, 2026, read 2026-08-25, amendment history through 89 FR 98559 (December 9, 2024). Section 6226 of Public Law 119-75 (140 Stat. 684), enacted February 3, 2026, read 2026-08-25 on govinfo. CMS, Private Payor Rate-Based CLFS FAQs, updated July 14, 2026, read 2026-08-25. CMS, CLFS and PAMA Reporting and Resources page, last modified August 3, 2026, read 2026-08-25. Quotes are verbatim except this site’s typographic rule: no dash characters, so quotes are split around any dash in the original.