In April, Thompson was penalized four strokes for replacing her ball incorrectly on the green while playing the 17th hole during the third round of the 2017 ANA Inspiration. The infringement was reported in by a TV viewer and assessed after completion of the round, which meant that in addition to receiving a two stroke penalty for replacing the ball incorrectly, she was also penalized two strokes for signing an incorrect scorecard. Despite this, she got into a playoff, eventually losing to Ryu So-yeon.