During this time Lenz also landed guest appearances on Off Centre, Charmed, Felicity, Maybe It's Me and The Guardian.
In 2002 Lenz joined the cast of Bring It On Again as Marni Potts, the co-captain of the varsity cheerleading squad.
When she was twenty-two, Lenz was cast in the WB television series One Tree Hill.
She originally auditioned for the roles of Brooke Davis and Haley James.
After eight seasons on air, One Tree Hill returned for thirteen episodes in its ninth and final season, with Bethany famously sashaying around in thigh high boots to save her husband.
On November 17, 2011, Lenz filmed her last scenes as the character Haley James Scott. In September 2012, it was confirmed that Lenz would be guest starring on an episode of Men at Work.
In March 2013 it was confirmed that Lenz would have a recurring role on Dexter.
Her character Cassie was described as "an attractive former finance executive looking for a quieter life".
In the sixth season, Lenz made her directorial debut.
Lenz's character appeared in the fourth episode of the final season.
In late September 2013, Lenz landed the role of Lauren Byrd on the pilot Songbyrd for E! The show centered around Lauren, a genius songwriter who employs a small staff, including her sister, to enable and manage her eccentric, yet wildly successful process.
Lenz eventually went on to appear in commercials for Eggo Waffles, Dr Pepper and others.
She continued to find work steadily as an actress, and by her sophomore year in high school she landed the role of Linda Halleck in Stephen King's Thinner.
She landed the role of Haley James, the quintessential girl-next-door, who is best friends with Lucas Scott, portrayed by Chad Michael Murray, and wife of Nathan Scott, portrayed by James Lafferty.