The PACT Study is a cluster randomised trial of a health coach-led patient activation program in type 2 diabetes. The goal of this clinical trial is to evaluate the effectiveness of a health coaching intervention (PACT program) led by Care Coaches (trained lay persons), in adult participants with sub-optimally controlled Diabetes Mellitus, as compared to participants undergoing routine care for diabetes (Usual Care). The primary outcome of interest is change in Glycated Haemoglobin (HbA1c) levels over 3 months, 6 months and 12 months. Secondary outcomes include changes in blood pressure, low-density lipoprotein-cholesterol (LDL-C) levels, body mass index (BMI), self-reported diabetes self-care behaviours, self-efficacy, health-related quality of life, and diabetes-related distress, over 3, 6 and 12 months. Participants in the Intervention arm will undergo the PACT Program, which is a 3-month long health coaching program led by a care coach. Participants review their motivators, health parameters, self-care behaviours, and set goals for improving their diabetes using a PACT report. Subsequently, they will receive fortnightly motivational and problem solving support via telephone or WhatsApp messaging over a 3-month duration, and will return to routine care after 3 months. Participants in the Usual Care arm will have routine care of their diabetes treatment.