Prior to being elected, MacMaster worked as an investment advisor with BMO Nesbitt Burns, and authored a monthly column for the Nova Scotia Business Journal entitled "Building Your Wealth". He also worked as an assistant to the former MLA'S for Inverness.
MacMaster was first elected to the Nova Scotia House of Assembly in a by-election on October 20, 2009.[3][4] He served as Chair of the Public Accounts Committee from 2009 to 2018, acting as Chair of the committee from 2013 to 2018.[2]
In March 2010, MacMaster issued a rare Gaelic resolution in the Nova Scotia House of Assembly, asking for continued government support for Gaelic language, history and culture in Nova Scotia. It was passed unanimously by all members.[5]
In his first full session in the legislature, MacMaster introduced two bills: An Act to Provide Greater Flexibility for Nova Scotians' Retirement Savings in Locked-in Accounts[6] and An Act to Amend Chapter 31 of the Acts of 1996, the Sales Tax Act which would prohibit the province from proposing or agreeing to an increase in the provincial portion of the federally enacted harmonized sales tax.[7]
In 2012, he brought the idea forward to extend pension wind up for Newpage pension plans during debate on Bill 96 Pension Benefits Act in 2011, but this was voted down.[8] A new bill was created for the same purpose and passed.[9]
Since 2013, he has been an advocate for patient safety and the access to a CT scanner at the Inverness hospital,[10] and a voice for those opposing the "Royal" designation of the Gaelic College in Cape Breton.[11]
In October 2014, MacMaster delivered a speech in the legislature about the struggles faced by victims of sexual abuse.[12]
MacMaster was re-elected in the 2013 election,[13][14] the 2017 election and again in the 2021 election. He was appointed Deputy Premier, Minister of Finance and Treasury Board, Gaelic Affairs and Labour Relations on August 31, 2021.[15]
