In this period, he was quoted by The Sydney Morning Herald as a critic of Opposition Leader John Brogden's policies on health.
[1] On 23 January 2007, he was preselected for the New South Wales electoral district of Macquarie Fields by the Labor Party, following the disendorsement of incumbent MP Steven Chaytor.
During the government of Morris Iemma, journalist Imre Salusinszky recommended that McDonald be appointed Health Minister.
McDonald was re-elected in the 2011 New South Wales state election for the electoral district of Macquarie Fields, suffering a 9.9-point swing towards the Liberal Party.
[15] McDonald continued to work one day a week as a paediatrician while serving as Member for Macquarie Fields and as Shadow Minister for Health.