CPT code 99409 represents a clinical encounter in which a provider spends more than 30 minutes screening a patient for alcohol or other non‑tobacco substance abuse and conducts a brief intervention in the same session. This code captures time‑based, behavioral health screening and early intervention services that aim to identify problematic substance use and deliver targeted counseling or motivational strategies during an ambulatory visit. Nationally, such services are a focus of public health efforts to reduce substance-related harm and to integrate behavioral health into primary care. Key payers included in this analysis are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will learn how CPT code 99409 is defined clinically and operationally, which sites of service typically bill for it, and what payers commonly cover this service. The publication also summarizes benchmark considerations, billing documentation expectations, and relevant policy context for time‑based behavioral screening and brief intervention services. Data not available in the input will be noted where applicable.