Patients with established diagnosis of type 2 Diabetes Mellitus (DM) who are on OHA monotherapy or combination OHA and are scheduled to undergo ambulatory surgery will be identified. Informed consent will be obtained from 160 consecutive study participants. Patients will be randomized into 2 groups - OHA treatment on day of surgery (Metformin continue) (H1 group, n= 80) and patients not receiving OHA on day of surgery (OHA discontinue) (H0, n=80) as prescribed by their provider. All patients will be processed through the anesthesia preoperative clinic and instructions regarding preoperative medication handling will be provided to study participants by the investigator. The instructions will be reinforced by the clinic nursing staff in the usual fashion.