The 31-year-old has been considering his future in the category and has now decided that this season will be his last before becoming a co-driver from 2019 onwards.
Speedcafe.com understands that Macauley Jones is among the contenders for the seat.
“It is obviously a very tough decision to step down from full-time driving, but a decision I have made myself and one that I am comfortable with,” said Blanchard.
“Supercars is more competitive than ever before with very little separating the entire field, nevertheless the results haven't been to the standard I would like, therefore I had to start thinking about what changes needed to occur for this to change and what I wanted to achieve personally longer term.
“I have a keen interest in the management side of the sport and am keen to start exploring that.
“I still enjoy driving and will continue to do so in the Pirtek Enduro Cup alongside any other opportunities that arise.
“We are still working out who will drive the TBR entry in 2019, I had to decide on my own driving first and now that decision has been made we will work on assessing all realistic options in the coming weeks.”
After a season of co-driving in 2014 he returned to full-time racing with Lucas Dumbrell Motorsport in 2015, where he finished a career best 21st overall, before moving to the Brad Jones Racing stable from 2016.
It was at the end of that season when Blanchard purchased his own REC that has underpinned his entry for the last two years.
“The purchase of the REC was always part of a longer-term plan that included post my full-time driving career,” said Blanchard.
“Tim Blanchard Racing (TBR) will continue its association with BJR in 2019 and I will be involved in ensuring that TBR is set up for a long and successful stint within Supercars.”
Blanchard will have contested 84 Supercars rounds when this season reaches its culmination at the Coates Hire Newcastle 500 later this month.