Background: Adrenocortical carcinoma (ACC) is a rare but aggressive malignancy, and many prognostic factors that influence survival remain undefined. Individually, the GRAS (Grade, Resection status, Age, and Symptoms of hormone hypersecretion) parameters have demonstrated their prognostic value in ACC. This study aimed to assess the value of a cumulative GRAS score as a prognostic indicator after ACC resection. Methods: A retrospective cohort study of adult patients who underwent surgical resection for ACC between 1993 and 2014 was performed using the United States Adrenocortical Carcinoma Group (US-ACCG) database. A sum GRAS score was calculated for each patient by adding one point each when the criteria were met for tumor grade (Weiss criteria ≥ 3 or Ki67 ≥ 20%), resection status (micro- or macroscopically positive margin), age (≥ 50 years), and preoperative symptoms of hormone hypersecretion (present). Overall survival (OS) and disease-free survival (DFS) by cumulative GRAS score were analyzed by the Kaplan–Meier method and log-rank test. Results: Of the 265 patients in the US-ACCG database, 243 (92%) had sufficient data available to calculate a cumulative GRAS score and were included in this analysis. The 265 patients comprised 23 patients (10%) with a GRAS of 0, 52 patients (21%) with a GRAS of 1, 92 patients (38%) with a GRAS of 2, 63 patients (26%) with a GRAS of 3, and 13 patients (5%) with a GRAS of 4. An increasing GRAS score was associated with shortened OS (p < 0.01) and DFS (p < 0.01) after index resection. Conclusion: In this retrospective analysis, the cumulative GRAS score effectively stratified OS and DFS after index resection for ACC. Further prospective analysis is required to validate the cumulative GRAS score as a prognostic indicator for clinical use.