You mentioned "I think the restrictions may somehow vary by state though because my experience with PT in NH does not match the experience that a relative in MA has had."

Medicare rules are the same for everyone, put in place by the Federal government. The "reporting" discrepancy in PT is most likely based on the terms of your supplementary Medicare policy, which may vary by state, because that is who regulates the health insurance companies. But underneath it all, the policy must comply with Medicare rules, which covers PT policies. It is an enormous, complex web, and part of what contributes to the high cost of our insurance and medical care. Medical practices and facilities have entire departments that do nothing except deal with Medicare and private insurance coverage and the complexities of coding each segment of care so that it gets paid for.

But if there is no progress, or the patient is deemed "non-compliant" (like failing to do the at-home exercises, or failing to show up for appointments) Medicare payments will stop.
Sue