What can limit coverage for a service despite it being reasonable and necessary?

Coverage for a service can be limited despite it being deemed reasonable and necessary when the service is provided more frequently than allowed under National Coverage Determinations (NCD), Local Coverage Determinations (LCD), or established clinically accepted standards of practice. These determinations set specific criteria that outline the circumstances under which services are covered, including frequency limits.

For example, a service may be necessary for a patient's diagnosis or treatment, but if clinical guidelines dictate that it should only be performed a certain number of times within a specified period, exceeding that limit can lead to coverage denials. This is particularly relevant in fields such as physical therapy or certain diagnostic imaging services, where overutilization can lead to increased costs without additional therapeutic benefit.

In contrast, while inadequate documentation of a service might result in payment denial, it does not directly pertain to the concept of frequency limits as defined by coverage criteria. Similarly, being outside a participating provider's network or lacking provider certification pertains to patient eligibility or practitioner qualifications rather than the inherent necessity of a service.