The final PBM fee disclosure rule describes the 953,420 small level-funded plans it leaves out as "90 percent of affected ERISA-covered group health plans" (91 FR 69184, section 12.2). Using the rule's own counts, 953,420 divided by 1,084,522 (953,420 plus the 131,102 covered plans) is 87.9 percent.
The January proposal's ratio, 1,031,098 small plans out of 1,150,583, was 89.6 percent, close to 90. BTP's hypothesis is that the department carried the older ratio forward. An alternative is that it used a different denominator. The worksheet that would settle it was not available. Footnote 437 also carries typos ("20254 KFF," "20221 County Business Patterns").
The same document gives two figures for 2024 drug spending: retail prescription drug spending of "nearly $495 billion" (91 FR 69093) and prescription drug spending that "increased by 7.9 percent in 2024 to $467.0 billion" (91 FR 69147). These are probably different CMS measures; BTP reports both and does not pick one.