Clinical and economic outcomes associated with venous thromboembolism (VTE) patient adherence to the American College of Chest Physicians (ACCP) anticoagulant (AC) treatment guidelines are incompletely understood. Patients with !1 inpatient or !2 separate outpatient claims for deep vein thrombosis and/or pulmonary embolism, based on International Classification of Diseases, Ninth Revision, Clinical Modification codes, were identified from the IMS PharMetrics Plus database. Patients had continuous insurance coverage for 12 months before (baseline) and after (follow-up) the index event (first VTE claim) but no baseline VTE claims. The ACCP recommends minimum AC treatment durations (3 or !6 months) dependent upon patient risk profiles. Patients were grouped into study cohorts based on their adherence status (adherent vs nonadherent) to the recommended minimum treatment durations. Patient baseline characteristics, health-care resource utilization, and associated costs were evaluated. The VTE recurrence and bleed-related hospitalization were measured during follow-up. Multivariate regression analysis was utilized to compare clinical and economic outcomes of cohorts. Of the 81 827 study patients, 74% (n ¼ 60 550) were AC adherent. After controlling for key patient characteristics, risks for all-cause hospitalization (adjusted odds ratio [AOR]: 0.85, P < .0001), VTE recurrence (AOR ¼ 0.92, P ¼ .0014), and bleeding-related hospitalization (AOR ¼ 0.74, P < .0001) were lower among adherent patients, as were all-cause health-care cost (ÀUS$2121, P ¼ .0003) and VTE-related (ÀUS$2294, P < .0001) and bleed-related (ÀUS$248, P < .0001) medical costs during the follow-up period. Approximately onequarter of the study population was AC nonadherent; these nonadherent patients had more VTE recurrences, utilized more inpatient services, and had higher health-care costs.