CPT Code 93971: Duplex Scan of Extremity Veins, Unilateral or Limited

CPT code 93971 can generally be billed only once per session per extremity, as it represents a unilateral or limited duplex scan of extremity veins. If a complete bilateral study is performed, CPT code 93970 is used instead.

The key difference between CPT codes 93970 and 93971 is that 93970 is for a complete bilateral study of extremity veins, while 93971 is for a unilateral or limited study, which can also include limited bilateral studies but not full bilateral exams.

CPT code 93971 is typically used in conjunction with an eligible secondary diagnosis related to venous disorders or conditions that warrant a limited or unilateral venous duplex scan. The exact ICD-10-CM code depends on the clinical indication but should support the medical necessity of a unilateral or limited study. Additionally, only one preoperative scan is typically allowed per extremity, unless new clinical indications warrant repeat imaging.