Hospital readmission within 30 days of discharge (30-day readmission) is a high-priority quality measure and cost target. The purpose of this study was to explore the feasibility and efficacy of the Diabetes Transition of Hospital Care (DiaTOHC) Program on readmission risk in high-risk adults with diabetes. This was a non-blinded pilot randomized controlled trial (RCT) that compared usual care (UC) to DiaTOHC at a safety-net hospital. The primary outcome was all-cause 30-day readmission. Between 10/16/2017 and 05/30/2019, 115 patients were randomized. In the intention-to-treat (ITT) population, 14 (31.1%) of 45 DiaTOHC subjects and 15 (32.6%) of 46 UC subjects had a 30-day readmission (p=0.88) while 35.6% DiaTOHC and 39.1% UC subjects had a 30-day readmission or ED visit (p=0.72). The Intervention:UC cost ratio was 0.33 (0.13-0.79)95%CI (p<0.01). Among the 69 subjects with baseline HbA1c >7.0% (53 mmol/mol), 30-day readmission rates were 23.5% (DiaTOHC) and 31.4% (UC, p=0.46) and composite 30-day readmission or ED visit rates were 26.5% (DiaTOHC) and 40.0% (UC, p=0.23). In this subgroup, the Intervention:UC cost ratio was 0.21 (0.08-0.58)95%CI (p=0.002). The DiaTOHC Program is feasible and may decrease combined 30-day readmission/ED visit risk as well as healthcare costs among patients with higher HbA1c levels.