Obtaining insurance approval for healthcare services, especially physical therapy, requires navigating health plan requirements. When a specific treatment, extended care, or durable medical equipment is needed, a formal document must be submitted to justify the expense to the payer. This documentation is known as a Letter of Medical Necessity (LMN). A common question is whether the physical therapist is qualified to prepare this document. This article clarifies the PT’s role in authoring the LMN and details the information required to secure coverage.
Defining the Letter of Medical Necessity
A Letter of Medical Necessity is a formal document required by insurance payers (which can include private companies, Medicare, or Medicaid) to justify that a requested treatment, service, or equipment is necessary for a patient’s condition. The core purpose of the LMN is to establish that the service is required to diagnose or treat a disease, injury, or impairment, rather than being for convenience. Without this document, the payer will often deny coverage. The LMN serves as a clinical argument, providing detailed medical evidence that the proposed treatment aligns with accepted standards of medical practice and will directly improve the patient’s health or functional status.
Physical Therapists’ Authority to Write LMNs
Physical therapists (PTs) can and frequently do write Letters of Medical Necessity, as they are the licensed healthcare professionals responsible for evaluating and determining the functional necessity of physical therapy interventions. The American Physical Therapy Association (APTA) defines medically necessary physical therapy as treatment determined by a licensed PT to minimize or eliminate functional limitations and impairments. This definition supports the PT’s authority to document why their skilled services are required to achieve a patient’s goals. However, the authority for a PT to submit an LMN without a physician’s co-signature is not universal and often depends on state-specific direct access laws and the specific insurance payer’s policy. Despite the PT providing the expert clinical documentation, the final administrative requirement often involves a medical doctor or doctor of osteopathic medicine (MD/DO) who must provide a prescription or signature for administrative approval.
Essential Elements of a Valid LMN
For an LMN to be accepted by a payer, it must contain specific clinical details that clearly justify the requested service. The letter must clearly state the patient’s diagnosis using standard coding and document functional limitations the patient currently exhibits. This should include objective data, such as measurements of range of motion, strength, or performance on standardized outcome tools. The letter must then detail the specific treatment, frequency, and expected duration being requested, directly linking the intervention to the patient’s condition. Measurable and time-bound goals must be established, focusing on functional outcomes to demonstrate anticipated improvement within a reasonable timeframe. The PT should also explain why alternative, less intensive, or previously attempted treatments have failed or are not suitable for the patient’s current needs. The argument must emphasize that the service requires the unique knowledge and clinical judgment of a licensed physical therapist.
The Final Approval Process and Physician Involvement
Once the physical therapist has completed the detailed clinical justification in the Letter of Medical Necessity, the document moves into the final administrative approval phase. Many payers, regardless of who authored the clinical content, require the LMN to be submitted along with a physician’s prescription or signature. This physician involvement serves as a final check to confirm the overall medical appropriateness of the request within the patient’s broader health context. The complete LMN package is then submitted to the insurance company or payer for review by a Medical Benefit Examiner. This reviewer determines if the evidence provided meets their specific medical necessity criteria, resulting in a determination of whether the requested services will be covered or denied based on the strength of the clinical justification provided.