[10] Van Garderen's first big senior race was at age 18 in the 2007 Tour of California as a part of the national team.

He won a stage of the Tour de l'Avenir and finished 24th in the under-23 race at the UCI Road World Championships in Varese, Italy.

Van Garderen started the Critérium du Dauphiné as joint leader of Team HTC–Columbia with Kanstantsin Sivtsov and Peter Velits.

This was van Garderen's first Tour de France and he was riding in support of Tony Martin and Peter Velits.

[15] In stage 8, van Garderen won enough points on a Category 2 climb to earn a King of the Mountains jersey and Most Aggressive Rider honors.

Van Garderen was selected for the Tour de France as one of the main domestiques for defending champion Cadel Evans.

He enjoyed a strong first week, coming fourth in the prologue and wearing the white jersey – for the best-placed rider aged 25 or under in the general classification – until stage 7, where he lost time on the first summit finish of the Tour.

In August, Van Garderen finished second in the USA Pro Cycling Challenge behind Christian Vande Velde (Garmin–Sharp).

[19] He had previously won the second stage of the race in a two-man sprint with Vande Velde, earning the yellow jersey in the process.

He also showed strong appearances as the European cycling season opened in March, finishing Paris–Nice in fourth,[21] and Critérium International in third place.

[28] He then went on to win the USA Pro Cycling Challenge, which included a lot of high altitude racing across Colorado.

[31] The Tour de France started out with hilly parcours in Yorkshire, with van Garderen finishing ninth on the second stage into Sheffield, won by Vincenzo Nibali.

[34] His BMC Racing Team also lost domestique Darwin Atapuma, who suffered a broken leg in the same crash.

[37] He repeated his success of the previous year at the USA Pro Cycling Challenge,[38] winning the general classification and two stages,[39][40] and finished the season with a gold medal in the team time trial at the UCI Road World Championships.

Prior to the COVID-19 pandemic, van Garderen intended to target the Giro d'Italia and the Tour de France in 2020.