Plummer married former Broncos cheerleader Kollette Klassen on August 26, 2007, who he met in 2005. In June 2010, Kollette gave birth to the couple's first child. After retiring from the NFL, Plummer moved to Sandpoint, Idaho (though the couple also has a house in Boulder, Colorado) where he lived in relative anonymity. His former agent Leigh Steinberg said he is "one of the minuscule few that I could see living a completely fulfilled life away from sport... he was as close to an egoless major star as I've seen." When a concerned Meals on Wheels supervisor in Sandpoint insisted her jobless, "scruffy", long-time volunteer keep track of the miles he drove for the organization for reimbursement, she was "dumbstruck" to discover he was a former NFL star.