In this cohort study involving 7989 hospitalizations over a 9-year period, implementation of a subcutaneous insulin treatment protocol for diabetic ketoacidosis at a single intervention site, compared with 20 standard care sites, was not associated with increased hypoglycemia but was associated with a relative reduction of direct intensive care unit admission of 57% and a 50% reduction in hospital readmission, with no change in hospital length of stay. Here, INS is linked to Hypoglycemia.