Background: There is paucity of data examining healthcare costs among persons with comorbid diabetes and cardiorenal conditions. Objective: To elucidate the longitudinal trends and quantify the incremental healthcare costs associated with the following cardiorenal conditions: atherosclerotic cardiovascular disease (ASCVD), heart failure (HF), and kidney disease, among persons with diabetes. Methods: Medical Expenditure Panel Survey data (2008–2019) were used to identify adults with diabetes and comorbid cardiorenal conditions. Overall, medical and pharmaceutical costs were ascertained (in 2019 US dollars). Analyses were adjusted for 14 variables using a two-part regression model. Results: Among 32,519 adults with diabetes, the mean (standard error [SE]) annual healthcare costs were $13,829 ($213), with medical and prescription components contributing $9301 ($172) and $4528 ($98), respectively. Overall healthcare costs rose by 26.8% from $12,791 (2008–2009) to $16,215 (2018–2019) over the study period, driven by 42.5% and 20.3% increase in pharmaceutical and medical spending, respectively. Similar trends were observed for subgroup of persons with cardiorenal conditions. Compared to their counterparts without cardiorenal conditions and prior to adjustment, persons with ASCVD, HF and kidney disease incurred healthcare costs that were approximately 2.2, 3.3, and 2.7 times greater. After adjustment, comorbid ASCVD, HF and kidney disease were associated with annual excess spending of $8651 (95% CI $7729–$9573), $9373 (95% CI $9010–$9736), and $9995 (95% CI $8781–$11,209), respectively. Conclusions: Study results are generalizable to non-institutionalized US persons. Healthcare costs associated with the management of diabetes are high—especially among those with comorbid cardiorenal conditions, and have risen in recent years.