Seven strokes ahead after opening with rounds of 62 and 66, the 58-year-old German star finished at 15 under 201 at TwinEagles. He also won in 2011 and 2013, was second in 2012 and tied for second in 2014.
Fred Couples had a 66 to finish second.
Using an approach of smart-aggressive, Langer was 1 over through 10 holes before making his first birdie on No. 11.
Couples drew within two shots with a birdie on 17 and Langer's bogey on 15. Couples had a three-putt bogey on 18, and Langer birdied 17 to push the margin to four. On 18, Langer put his second shot in the water and salvaged a bogey.