Short Answer
A physical therapy prescription (Heilmittelverordnung) becomes legally invalid if treatment does not begin within 28 days of the issue date.
You must secure your first appointment immediately after leaving the doctor's office to ensure the billing remains valid.
What Most Expats Don't Realize
You waited until your back pain was better to look for a clinic, only to find that every "Physiotherapie" in your area was booked for the next month. By the time you found a slot, your 28-day window had expired, and the clinic refused to treat you until you provided a fresh document. You lost a full day of work returning to your GP for a "reissue" and paid a second co-payment fee because you didn't book the sessions the day you got the paper.
What To Do
- Call at least three physiotherapy clinics the same hour you receive your prescription.
- Book the entire series of 6 or 10 appointments at once to ensure they fall within the legal timeframe.
- "Ich muss die Behandlung innerhalb von 28 Tagen beginnen." (I must begin the treatment within 28 days.) — Tell the clinic this to emphasize the deadline.
The Truth
Germany treats physiotherapy as a time-sensitive medical intervention rather than a wellness service. The 28-day rule is a hard cutoff enforced by insurance billing software.