Gaborone media reports said the 31-year-old, accused of using the banned substance methylhexaneamine during the Glasgow Games, will appeal the decision ahead of a March 26 deadline.
Botswana Athletics Association president Moses Bantsi confirmed the suspension.
Montsho was the athletics queen of Botswana, a thinly-populated, diamond-rich southern Africa country that rarely creates international sporting headlines.
She won gold at the 2010 Commonwealth Games in India and at the world championships in South Korea a year later.
The Botswanan missed out on more world championship gold in 2013 when pipped by Briton Christine Ohuruogu in a photo-finish in Moscow.