Korako stood for Christchurch City Council in the 2013 local elections in the Banks Peninsula ward. Based on preliminary results, he was just five votes behind Andrew Turner, with 80 special votes still to be counted. On the strength that he might get declared elected, Korako attended the induction meeting, and joined the council delegation that met Earthquake Recovery Minister Gerry Brownlee.[5] One week after the election, Turner was declared the winner with a five votes margin.[6]
Korako contested Port Hills for National in the 2014 election. He was selected as the National candidate over fellow contenders Lincoln Platt and Jason White, and had been asked to stand by former Banks Peninsula MP and current Speaker of the House David Carter.[3] The electorate was won by the incumbent Ruth Dyson of the Labour Party, but National polled well enough that Korako entered Parliament via the National party list.[7] He chaired the Māori Affairs Committee in his first term.
In 2016, Korako had a private member's bill drawn by ballot for debate in Parliament. The Airport Authorities (Publicising Lost Property Sales) Amendment Bill would allow airports to decide the best way to advertise lost property for sale.[8] The Bill was criticised by Labour, New Zealand First and ACT for being a minor law change that could have been achieved through other legislative means.[9][10] The Government eventually progressed Korako's sought amendments through a Statutes Amendment Bill, rather than a standalone law change.[11]
Korako was re-elected as a list MP in the 2017 election, having failed to unseat Dyson for a second time. National was in Opposition from the election; Korako served as the party's spokesperson for Māori Affairs and Treaty of Waitangi Negotiations from November 2017 to May 2019, when he retired.
In mid-April 2019, Korako announced his retirement from politics,[12] which took effect on 16 May 2019. He was succeeded by Paulo Garcia.[13][14]