"Subaru has a rich heritage in the US and we are excited to celebrate the six-million-vehicle milestone," said Thomas J. Doll, executive vice-president and Chief Operating Officer of Subaru of America.
"Not only have we sold six million vehicles in the US, but we are selling them at a faster rate than ever. It took us 16 years to reach our first million, but at our current sales rate we will hit our next million in under three years.
"We have enjoyed more than four decades of sales to loyal and enthusiastic American buyers," said Doll.
"We are also proud that 96 per cent of Subarus built in the last 10 years are still on the road today. That speaks for the longevity of Subaru vehicles."
In the US market, Subaru is the only carmaker to have five consecutive years of sales increases during 2008-2012. The brand has also shattered its previous annual sales records for the past four years.
Subaru broke its 2011 annual sales record in October, with more than two months remaining in the year.