Rob Anderson, who represents the riding of Airdrie, announced the news on his Facebook page late Monday night.
The post says that he met with Premier Jim Prentice before Christmas to let him know he wouldn't be running again.
Anderson was first elected in 2008 as a Conservative, but crossed the floor to join the Wildrose Party in 2010.
In December, he and eight Wildrose MLAs, including then leader Danielle Smith, crossed the floor to join the Tories.
Anderson says in his Facebook post that he and his wife will purse careers in the private sector while spending more time with their four boys aged five to 10.
"Serving as the MLA for Airdrie (and Airdrie-Chestermere prior to 2012) has been one of the greatest experiences and honours of my life. So many of my most cherished friendships and memories stem from my time in this role. I will spend my remaining time as MLA continuing to work on establishing 24-hour health care services in Airdrie, improving conditions for seniors at Airdrie’s Bethany Care Centre, and assisting Premier Prentice with what will be a very challenging and important budget during a time of great economic uncertainly for our province."
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