Objective: Using claims data from an integrated payer-provider, we compared costs incurred by patients with insulin-dependent diabetes mellitus (IDDM) who received Hospital Inpatient/Observation/EmeRgency Department care (HIghER care) for diabetes-related events with those who did not receive such care to identify a target population for interventions in future studies., Methods: A retrospective study pooled real-world claims data for IDDM (type 1 or type 2) between July 1, 2018, and June 30, 2019. Medical claims were used to calculate the total and diabetes-related allowed medical costs to the enterprise and per member per month costs., Results: Medical and prescription drug coverage from 19 378 members was analyzed. Only 8.4% of the IDDM population received HIghER care but incurred 20% of medical expenses and nearly 40% of diabetes-related medical costs. For HIghER care patients, medical spending was higher in every inpatient and outpatient category (Wilcoxon 2-sample tests, all P < .0001). Non-diabetes-related prescription drug costs were greater in this group (Wilcoxon test, Z = 2.2879, P = .0221), whereas diabetes-related prescription drug costs were higher for non-HIghER care (Wilcoxon test, Z = -9.5918, P < .0001). In a longitudinal study of 29 602 patients over 24 months, previous-year receipt of HIghER care was a significant predictor of HIghER care the subsequent year (odds ratio, 3.28)., Conclusion: Medical spending for patients receiving HIghER care was disproportionately high and greater in every inpatient and outpatient category. HIghER care receipt the previous year was highly predictive of HIghER care episodes the following year., (Copyright © 2022 AACE. Published by Elsevier Inc. All rights reserved.)