modifier 26

My pulmonary physician interprets a PFT that was performed at the hospital, two days after the test was performed. I'm billing the service with modifer 26 but should the date of service be the date the test was performed or the date my physician interpreted the results?

Dos

The Centers for Medicare & Medicaid Services (CMS) announced on Friday, February 5, 2010, that it has rescinded Change Request (CR) 6375, Transmittal 1873 sent via RO-6657, dated December 11, 2009, and will replace it with another CR in the future, pending further policy clarification on date of service and place of service reporting for the interpretation of diagnostic tests.
This is what was rescinded: The Transmittal 1823 also reminds providers that the date of service for a test interpretation is the actual calendar date that the interpretation was performed even though this may be different from the date of the technical component of the service: http://www.cms.hhs.gov/transmittals/downloads/R1823CP.pdf