Because of the huge contribution of St John in New Zealand during World War Two, the Commandery was elevated to a Priory in 1946. This began a new era for St John, giving it greater autonomy and influence. The Governor-General now became Prior, not Patron or President, as had been the case since 1885.

Following the Second World War, the work of St John diversified, Mobile health clinics were established, and the Order expanded its blood collection service, the first in the country. Demand for first aid training increased and industry-based centres were established for the waterfront and railways. A tutor for the forestry industry was also appointed. In 1960, our 131 ambulances travelled 1.1 million miles carrying 101,000 patients. There were 94 salaried ambulance drivers supported by 512 volunteers. Brigade membership stood at 7,948 adults and cadets.

By the middle of the 1970s St John recognised the need to review its ambulance service activities. As the majority provider of the nation's ambulance service, it needed to respond to the Government's requirements that the revamped Ambulance Transport Advisory Board become a more effective organisation.

The day of the ambulance travelling at breakneck speed with patients tended by personnel holding only basic first aid certificates was over - Staff would now be encouraged to obtain, and eventually be required to hold formal qualifications. To assist the Order to reach this goal, the first Telethon held in New Zealand raised over half a million dollars in 1975 to establish a national ambulance training centre, under the auspices of St John. That year our ambulances travelled 2.815 million miles, were crewed by 1120 personnel and carried 251,000 patients. Our Brigade personnel stood at 12,041 adults and cadets.

At the same time, the Association and Brigade redefined their roles in respect of training services, with the Brigade moving away from providing tuition and this role being taken up by a greater number of paid staff. At the same time first aid training was becoming more sophisticated, with the introduction of CPR and radical new treatments for injuries such as the use of blow up splints for fractures and water treatment for burns.

In response to falling Brigade numbers, a shrinking economy and competition for the provision of training services. The Order in New Zealand took a major step in 1987 to reorganise. The Brigade (11,439 adult and youth members), moved away from its traditionally militaristic structure (cadets became youth members, officer positions were revised and renamed and the Brigade became Community Services). St John established three service arms - Community Services, Ambulance and Training, supported administratively by members on a general roll. The Association was radically transformed to become more supportive of the Community Services Arm, taking on much of its administrative work and coordinating the work of the three service arms.

St John has continued to consolidate and reorganised on a functional basis in 2001, leaving the five regional entities and governance structure unchanged. Managers for each of 12 functional activities (with responsibility to the Chief Executive) prescribe the way in which the products and services provided by St John will be delivered throughout New Zealand. In this way, the community will be assured of consistency in the manner in which St John, as a national organisation, operates throughout the country in fulfilling its charitable purposes. New and diverse services, such as Caring Caller, Safe Kids and Healthline have also been introduced.