OBJECTIVES: Generalized convulsive seizures (GCS), including clonic, myoclonic, and tonic-clonic seizures, account for 40% of epilepsy seizures. Patients with GCS, especially uncontrolled disease, may accrue significant healthcare resource utilization and associated costs. These parameters were estimated in adult patients with GCS. METHODS: Adults (≥18 years) with ≥2 GCS claims (ICD-9 code: 345.1x) 30 days apart during index year were identified from OptumInsight® claims database (2011-2013). Continuous enrollment in their US healthcare plan (medical and pharmacy benefit) for  ≥1 year before and after index date was required. Eligible patients were categorized as having stable disease (no change in anti-epileptic drug [AED] over 12 months) or uncontrolled disease (added AED to an existing regimen). Index date was selected during calendar year 2012 (stable disease, convenience date; uncontrolled disease, date of additional AED initiation). Pharmacy and medical claims during post-index year were used to estimate overall and epilepsy-related resource utilization and costs. Analysis of covariance was used to compare outcomes after adjusting for baseline differences between groups. RESULTS: Annual estimates were based on 1,201 patients (1,067 stable/134 uncontrolled): mean age, 40 years; female sex, 54%/55%; and mean Charlson comorbidity index, 0.70/0.90.  Inpatient and outpatient ER rates were 15.6% (epilepsy-related 10.6%) and 32.0% (epilepsy-related 15.9%) for stable patients, and 23.9% (epilepsy-related 22.4%) and 42.5% (epilepsy-related 27.6%) for uncontrolled patients. Associated mean costs were substantially less for stable ($16,487; epilepsy-related, $6,570) than uncontrolled ($30,648; epilepsy-related, $16,102) patients. After adjusting for baseline characteristics, the difference was significantly less: $10,928 (P=0.0006); epilepsy-related $8,769 (P<0.0001). CONCLUSIONS:  Patients with uncontrolled GCS accrue significantly more healthcare resource utilization. Uncontrolled GCS patents have considerably higher costs for both total and epilepsy related than stable patients (39%, total overall annual costs, 57%, epilepsy related). Early and effective disease management of patients with uncontrolled GCS may mitigate the high economic burden.