Week 17, Parker earned his first career start and collected a season-high six solo tackles, broke up two passes, and intercepted a pass by Philip Rivers during a 27–24 loss at the San Diego Chargers. He finished the 2013 NFL season with 17 solo tackles, three pass deflections, two interceptions, and one sack in 16 games and one start. The Kansas City Chiefs finished the 2013 NFL season second in the AFC West with an 11–5 record and earned a wildcard berth. On January 4, 2014, Parker appeared in his first career playoff game and made one solo tackle in their 45–44 loss at the Indianapolis Colts in the AFC Wildcard Game. 2014 Throughout training camp, Parker competed to be a starting cornerback against Sean Smith, Marcus Cooper, and Phillip Gaines. Head coach Andy Reid named Parker a starting cornerback to start the regular season in 2014. He started alongside Marcus Cooper and safeties Eric Berry and Husain Abdullah. He started in the Kansas City Chiefs' season-opener against the Tennessee Titans and recorded six solo tackles and broke up a pass in their 26-10 loss. Parker started at strong safety in place of Eric Berry who was inactive for five games (Weeks 3-8) with an ankle injury. On October 26, 2014, Parker made four solo tackles, a pass deflection, a sack, and intercepted a pass during a 34-7 victory against the St. Louis Rams in Week 8. In Week 11, he collected a season-high 11 solo tackles in the Chiefs' 24-20 win against the Seattle Seahawks. Parker was moved to strong safety for the last five games of the regular season after Eric Berry was diagnosed with Hodgkin's lymphoma. He finished the 2014 NFL season with a career-high 94 combined tackles (81 solo), 12 pass deflections, one interception, one sack, and a forced fumble in 16 games and 15 starts. 2015 Parker became an unrestricted free agent in 2015 and received interest from multiple teams, including the Tampa Bay Buccaneers, Atlanta Falcons, New York Giants, and New York Jets. On March 16, 2015, the Kansas City Chiefs signed Parker to a five-year, $30 million contract that included $8 million guaranteed and a signing bonus of $5 million. Parker entered training camp slated as the starting strong safety. Head coach Andy Reid named him the starter to begin the regular season, alongside free safety Husain Abdullah. In Week 4, he collected