Endocrinology Prior Authorization and Denial Guide
Continuous glucose monitor and insulin pump prior authorization requirements, DEXA scan frequency rules, thyroid imaging documentation standards, and denial patterns for diabetes technology and endocrine diagnostic services. Grounded in CMS LCD L33822 for CGMs, CMS LCD for external infusion pumps (L33794), NCD 150.3 for insulin pumps, and major commercial payer policies for diabetes device coverage.
Continuous glucose monitor coverage: Medicare covers CGMs under the DMEPOS benefit for patients with diabetes who use insulin (multiple daily injections or insulin pump) or who have hypoglycemia unawareness. CMS LCD L33822 specifies the qualifying criteria. Commercial payer coverage is broader but requires prior authorization and documentation of insulin use, frequency of self-monitoring, and A1C or hypoglycemic episode history. CGM sensors (CPT A9278) and receivers require separate PA for many payers, and the transmitter is typically included in the sensor authorization.
Insulin pump (CSII) coverage: Medicare NCD 150.3 requires that the patient meet specific criteria including C-peptide level below threshold (confirming insulin dependence), failure of multiple daily injections to achieve adequate control, and demonstrated ability to use the pump. DEXA scan frequency: Medicare covers DEXA every 24 months for patients with risk factors or prior osteoporotic fracture; more frequent scanning requires documentation of a change in treatment or a condition expected to result in rapid bone loss. Thyroid ultrasound for nodule evaluation follows ACR TI-RADS reporting categories — coverage for repeat ultrasound surveillance requires documentation of nodule size category and prior result.