These were the first links in the chain of interstate contributor service offices, which was completed in 1969 with branches in all States of the Commonwealth. Interstate operations were maintained until changes in the National Health Act in 1970, when the Fund decided to limit its activities and service to NSW, the ACT and Northern Territory. The expanding years 1972–1982 In October 1974, HCF, in association with MBF, challenged the refusal by the then Commonwealth Minister for Social Security to approve increases in contribution rates which the funds required to meet benefit payments on higher public hospital charges. The case was heard in the NSW Supreme Court, the fund's challenge was successful and the new rates were introduced in accordance with the original submissions. The Commonwealth Government's Medibank (now Medicare) fund was established in 1975, and provided medical benefits of 85% of the Schedule Fee for everyone in the community under an income tax levy system. (Medical services coverage from 1 July 1975, followed by hospital coverage from 1 October 1975). This provided HCF and all other Australian health funds with a government run competitor whose services were compulsory. To maintain its community service role in this new environment, HCF introduced its Multicover plan from 1 July 1975, providing cover for the medical "gap" (the difference between the Medibank benefit and the Schedule Fee) and for a wide range of other health care services, such as dental, optical, physiotherapy, home nursing and overseas health care, which were not covered by Medibank. In November 1975, the head office staff completed their occupation of HCF's new premises at 403 George Street Sydney, which have since been extended to accommodate additional staff and facilities needed to provide the Fund's expanding services. Towards the end of 1977, HCF took court action to appeal to the Administrative Appeals Tribunal against the refusal by the then Minister for Health to approve a contribution increase required to meet higher provider charges. Once again the Fund was successful. HCF Life Insurance Pty Ltd., a wholly owned subsidiary company, was established in January 1980. The challenging years 1982–1992 In 1982 HCF celebrated its 50th anniversary. Its Annual Report reviewed its development since 1932. In 1983 the Federal Government introduced Medicare (Medibank's replacement) to cover medical and public hospital treatment. Health insurers were prevented from paying medical benefits. Like other registered health funds, HCF ceased to pay medical benefits on