CPT Code 93970: Duplex Scan of Extremity Veins

What is CPT code 93970?

The 93970 CPT code refers to a duplex scan of extremity veins, including both deep and superficial veins. This non-invasive vascular imaging test evaluates blood flow and vessel structure in both legs or arms, often to assess for phlebitis and thrombophlebitis, varicose veins, or suitability for bypass surgery or hemodialysis access site surgery.

It includes real-time B-mode imaging and Doppler analysis, providing a comprehensive view of venous circulation. It is distinct from CPT code 93971, which has a code description of duplex scan of extremity veins, including responses to compression and other maneuvers using unilateral or limited study.

Documentation requirements

To support medical necessity and meet correct coding guidelines, documentation for CPT 93970 should include:

• Reason for the scan: Clearly state clinical indications such as leg swelling, suspected deep vein thrombosis, evaluation of varicose veins, or preoperative examination for potential harvest vein grafts.
• Anatomical detail: Specify that both bilateral lower extremities or upper extremities were examined, including deep vessels and superficial veins.
• Complete study confirmation: The record must reflect a complete bilateral study, not a partial or limited one.
• Findings and interpretation: Include Doppler results on blood flow, presence of thrombosis or reflux, and any abnormalities affecting surgical planning or diagnosis.
• Eligible secondary diagnosis (if applicable): For cases like a non-pressure chronic ulcer, link findings to an eligible secondary diagnosis that supports medical necessity.
• Physician order and signature: Ensure the test was ordered by a qualified provider and is properly documented in the medical record.

Billing guidelines

Accurate billing for CPT code 93970 requires attention to payer rules and service specifics:

• Report 93970 for complete bilateral studies only: Use this code only when both extremities (e.g., right and left legs) are evaluated in full. If only one limb is studied or if the exam is limited, use CPT 93971 instead.
• Use only once per preoperative event: In pre-surgical evaluations (e.g., for bypass surgery), most payers will reimburse only one preoperative scan unless new clinical indications arise.
• Do not bill for screening: Screening tests performed without clinical symptoms or physician referral are typically not reimbursed unless allowed under specific payer policies.
• Avoid duplication: Do not bill 93970 with other vascular studies for the same body part on the same day unless separate medical necessity and anatomical regions are documented.
• Use appropriate diagnosis codes: Examples include I83.90 (asymptomatic varicose veins of unspecified lower extremity), I80.3 (phlebitis and thrombophlebitis of the lower extremities, unspecified), or Z01.818 (preprocedural examination). Using specific code helps validate medical necessity and ensure accurate coding.

Other relevant CPT codes

• 93925: Duplex scan of lower extremity arteries, complete bilateral study
• 93926: Duplex scan of lower extremity arteries, unilateral or limited study
• 93930: Duplex scan of upper extremity arteries, complete bilateral study