Medicare rx stipulations in english?

It used to be to go to physical therapy with medicare insurance you got a rx from your pcp and could go for 2 months then had to go back to your pcp for a new rx and then go back every month thereafter. Now the first rx is good for 90 days but how long is every rx after that good for?

…the 90 day extension was meant to reduce redundant paperwork, but it actually created more (because progress notes were typically written each 12 visits if PT was 3 times a week)…it's only less work for the MD who only has to sign the plan every 90 days. …but that's CMS for you.