A physical therapy (PT) prescription, also known as a referral or physician’s order, is a directive from a qualified healthcare provider detailing the type and frequency of rehabilitation services a patient should receive. The duration of this order is complex and not determined by a single rule. A prescription’s effective lifespan is subject to three main factors: the internal administrative policies of the clinic, the authorization rules set by the patient’s insurance company, and the specific laws governing PT practice in the state where treatment occurs. Understanding these constraints is important for ensuring continuous care and coverage.
Initial Validity: The Shelf Life of the Referral
The first limitation on a physical therapy prescription is its administrative shelf life before treatment begins. This is the period within which the initial evaluation must occur. Many clinics will not accept an order if too much time has passed between the date it was written and the patient’s first appointment.
The specific administrative limit often falls between 30 and 90 days from the signing date. If a referral is older than this internal time frame, the clinic typically requires a new one from the prescribing provider. This ensures the order reflects the patient’s current medical status, as a condition can change significantly over a few months.
If no specific expiration date is mandated by state law or insurance, the physical therapist’s professional judgment determines if the referral is still medically relevant. They may contact the referring practitioner to confirm the patient’s status and the continued need for therapy before proceeding. This initial validity period is separate from the total duration of care once therapy has commenced.
Clinical and Payer-Defined Treatment Limits
Once a patient begins therapy, the primary limitation shifts from the initial referral date to the authorization limits imposed by the payer, typically the insurance company. Although the prescription may suggest a duration, such as “PT for six weeks” or “12 visits,” the insurer’s determination of “medical necessity” is the ultimate constraint. Medical necessity requires that services are essential for treatment and show a reasonable expectation of measurable improvement.
Many commercial insurance plans impose hard annual caps on the number of visits, often ranging from 20 to 60 sessions per calendar year. Coverage is also managed through “authorization blocks,” where insurers initially approve a small number of visits, frequently 6 to 8 sessions.
As these initial visits near completion, the physical therapist must submit documentation to request authorization for the next block of treatment. This involves a detailed review of the patient’s objective progress and the necessity of continued skilled intervention. While Original Medicare has no hard cap on medically necessary visits, many Medicare Advantage plans impose limits and require prior authorization. If the insurer determines the patient has reached maximum functional improvement or the therapy is no longer considered “skilled,” they can deny further authorization.
State Regulations and Direct Access Limitations
State law imposes a distinct set of limitations on physical therapy duration, defined within each state’s Physical Therapy Practice Act. These rules apply regardless of whether a patient has a prescription or insurance approval.
The most common constraint relates to “Direct Access,” which allows patients to see a physical therapist without a physician’s referral. Even where Direct Access is permitted, the ability to treat the patient without a physician’s order is often legally capped by a time limit or a maximum number of visits.
For example, state laws may limit treatment to 10 sessions or 30 days, or allow up to 90 days before a physician’s involvement is required. Once this statutory limit is reached, a formal prescription or signed plan of care from a qualified practitioner is legally mandated to continue care. This requirement ensures the patient’s condition is reviewed by a broader medical authority. These limitations are separate from insurance rules; a patient may have coverage for more visits but be legally barred from receiving them without the required physician signature.
The Renewal and Reauthorization Process
When limits set by the initial prescription, insurance authorization, or state law are reached, treatment must undergo a renewal and reauthorization process to continue care. This requires coordination among the physical therapist, the prescribing physician, and the insurance company.
The physical therapist prepares a detailed progress report and an updated plan of care. This documentation must include objective measurements of improvement and a rationale for why continued skilled therapy is necessary.
This documentation is sent to the original prescribing physician, requesting a renewed prescription. If the physician agrees with the necessity for continued treatment, they issue a new prescription or sign the updated plan of care, often required at least every 90 days. This new order resets the validity clock for the medical order.
The renewed prescription and the therapist’s documentation are then submitted to the insurance company to request a new authorization block. The payer reviews the information to ensure the continued treatment meets medical necessity criteria before approving additional visits. Gaps in treatment can occur if this process is not managed proactively, leading to a temporary halt in services until new approvals are secured.