What Does Letter of Medical Necessity (LMN) Mean?
A letter of medical necessity (LMN) is a letter issued by a person's physician describing why a requested treatment is necessary. LMNs are often used to justify a request for specific medications, medical equipment, or therapy.
These letters may be required by an individual's private insurer or other agency before payment will be authorized for the requested treatment. Letters of medical necessity may also be needed by individuals traveling with medical equipment or medications. The LMN demonstrates to customs and other officials that the person requires the item and should be permitted to keep it with them. In some cases, a LMN may be provided to an employer to explain a specific accommodation requested or an out of the ordinary medical situation.
A letter of medical necessity may also be called a doctor's statement.