Summary & Overview
CPT 78999: Miscellaneous Diagnostic Nuclear Medicine Procedure
CPT code 78999 designates a miscellaneous diagnostic nuclear medicine procedure used when no specific CPT code exists for a performed study. As a catch‑all code, it matters nationally because it enables billing for novel, uncommon or institution‑specific diagnostic nuclear medicine services that fall outside established code descriptions. Proper use of this code affects claims adjudication, clinical documentation and coverage determinations across payers.
Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare and Medicare. Readers will find a concise overview of the code’s clinical scope and typical sites of service, plus a framework for understanding payer coverage considerations and common billing practices. The publication outlines benchmarks and variability in how payers treat miscellaneous nuclear medicine reporting, highlights documentation elements required for claim support, and summarizes policy and coding implications practitioners should consider when 78999 is used.
The content is intended for a national audience of billing managers, radiology and nuclear medicine clinicians, and compliance staff who need clarity on when 78999 is appropriate, what information payers typically expect, and where ambiguity may require additional coding or prior authorization steps. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 78999 is a miscellaneous diagnostic nuclear medicine procedure code used to report a diagnostic nuclear medicine service that does not have a specific CPT code. It covers procedures in the nuclear medicine diagnostic space that are not described elsewhere in the CPT manual.
Service Type: Diagnostic nuclear medicine procedure
Typical Site of Service: Hospital outpatient department, ambulatory imaging center, or other outpatient facility where diagnostic nuclear medicine studies are performed.
Clinical & Coding Specifications
Clinical Context
A patient is referred to nuclear medicine for a non-routine diagnostic scintigraphic study that does not match an existing CPT code. Typical scenario: a 62-year-old patient with a history of malignancy and atypical symptoms (focal pain and ambiguous imaging findings) requires a bespoke radiotracer scan to evaluate for occult metastatic disease in an anatomic region not covered by standard codes. The ordering clinician documents clinical indication, prior imaging, and the specific radiopharmaceutical and imaging protocol. The nuclear medicine team reviews the request, obtains informed consent, administers the radiopharmaceutical, performs serial planar and SPECT/CT imaging tailored to the region of interest, and provides a procedural report with images and interpretation. Billing uses 78999 to report the miscellaneous diagnostic nuclear medicine procedure; the report must include a clear description of the procedure, the radiopharmaceutical, acquisition parameters, time of administration, and justification for using an unlisted code. Typical site of service is an outpatient imaging center or hospital nuclear medicine department. Common payors involved include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, BUCA, and Medicare.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When billing professional interpretation distinct from technical services |