Does every note of every visit transcribed necessarily have to be signed in some fashion other than the transcriptionist's indicator of the physician dictating?

Yes. According to Amy D. Berret, an associate with Kean, Miller, Hawthorne, D'Armond, McCowan & Jarman in Baton Rouge, La., this is a federal Medicare/Medicaid requirement and not just an insurance carrier or state stipulation.  In general, the healthcare provider must sign the progress note as well as all reports of tests or test results.  The purpose of the requirement is to confirm that the services were actually performed.