It appears that almost no Part B claims wound up being processed at the reduced rate of -21%, even though Medicare contractors were technically supposed to begin processing claims at the lower rate on April 15. They had about one eight-hour business day to do so before Congress passed a pay-fix bill that reverses the cut effective to April 1 and lasting until May 31.
CMS released a vague statement saying that it's instructed contractors to process all currently held claims at the flat rate from the 2010 final Physician Fee Schedule. But the agency has no information on whether any claims -- however few -- were processed April 15 prior to Congress passing the pay-fix bill. "We don't have that information," a CMS spokeswoman told me in a one-line email.
That said, at least one contractor is reporting that it never processed any Part B claims at the lower rate. Highmark Medicare Services (HMS) released a brief and to-the-point statement: "HMS has not paid any claims at the proposed -21% reduced fee schedule. Therefore, no retroactive adjustments will be needed for claims processed by HMS. HMS will be releasing currently held claims on a first in-first out basis."