The aim was to make basic healthcare accessible for people in the Far North who were unable to afford it. The clinic had emergency prescription funds donated from New Zealanders around the country. In October 2012 O'Sullivan started the MOKO programme ("Manawa Ora Korokoro Ora" healthy heart, healthy throat), Northland's first full-time, school-based health clinic providing medical care to 2000 children within a 25 km radius of Kaitaia. Health Ministry provided support with additional funding from the charity KidsCan.. The program focuses primarily on preventing rheumatic fever by taking a throat swab from every child with a sore throat. The programme also provides basic medical care for nits, skin and chest infections with nurses and health workers visiting each primary and intermediate school three times a week. There are also two GP sessions each week to take care of more complex cases. The "Kainga Ora (Well Home)" initiative promotes the idea that wellness begins in safe, warm homes. The initiative commenced in 2012 when O'Sullivan drove around Kaitaia and called in to some of the most rundown looking houses. He found families living with children who were sick due to the condition of their homes. He recruited labour and donated materials to help repair the homes.  iMOKO started in 2014 as an extension the vMOKO programme. Trained nurses and health workers collected data including photographs and forward it to O'Sullivan's practice in Kaitaia. Photographs were taken as required and O'Sullivan provided a diagnosis or passed the data on for a higher-level diagnosis. iMOKO also provides the capability to send required prescriptions to a nearby pharmacy for collection. The programme saves families long trips to the clinic at Kaitaia, runs efficiently, and can detect disease in the early stages. By November 2016, 4000 children in approximately 35 early childhood centres, Kōhanga Reo, primary, intermediate and secondary schools participated in this healthcare model. In 2017, two virtual health clinics were opened: the first in the doctor-less town of Patea; the second in Kaitaia. The clinics enable patients to attend and access healthcare under the iMOKO model with the assistance of trained healthcare workers. In November 2017 the Accident Compensation Corporation and the Ministry of Health announced they would provide O'Sullivan's company, Navilluso Medical, $NZ1.4 million over two years to develop its MaiHealth model  During the COVID-19 Pandemic he publicly criticised the residents of Kaitaia for breaching the lockdown conditions, only to admit later on 22/4/2020 that he had breached the level 4 lockdown by going kayaking.