How Medicare Fits a Second Conversion Factor Into One Byte

CMS has shipped the 2026 physician fee schedule as two files since December 22.

One prices every code at 33.4009. The other prices the same codes at 33.5675.

Which one applies depends on whether the clinician who furnished the service is a Qualifying APM Participant for the year. That has been the statute since January 1 and the arithmetic since the January release.

This morning, 256 days into the payment year, the manual that tells contractors what the fee schedule file looks like caught up.

Transmittal 13912 (CR 14560) posted to the CMS transmittals page today, revising Chapter 23 of the Medicare Claims Processing Manual. Effective and implementation date: November 16, 2026. Its stated purpose is to revise "the MPFSDB File Layout to accommodate two different conversion factors as a result of the implementation of the Quality Payment Program (QPP)."

"Where do you put a second conversion factor in a record layout with room for one?"

The Byte Formerly Known as 31DD

The addendum to Chapter 23 is the MPFSDB record layout, the field-by-field spec for the file your MAC prices Part B claims from and your vendor's loader was built against.

The version in force runs 1 through 29, then 29A, 30, 31, then 31EE, 31DD, 31CC, 31BB, 31AA, then 31A through 31G, then 32A, 32B, 32C, then 33A, 33B, 33C, 33D, 33F, 33G, then 34, 35, 36, and finally 38A. Twenty-three of the identifiers carry letters. There is a 33F and a 33G with no 33E, and a 38A with no 38. That is what decades of inserting a field between two other fields looks like when nobody is allowed to renumber.

Transmittal 13912 renumbers it. Sixty fields, 1 through 60, sequential, no letters, no gaps.