The happy news comes one week after the New Girl actress, 35, and her producer fiance, 42, confirmed that they're expecting their first child together. Deschanel is due to give birth to the little one this summer.
Pechenik and the She & Him singer first stepped out together in August 2014, after her split from screenwriter Jamie Linden, whom she dated for two years. They made their red carpet debut at the 2014 Emmys, where they posed together at the Nokia Theatre in L.A.
This will be the second marriage for Deschanel. She was previously wed to Death Cab for Cutie vocalist Ben Gibbard; they split in 2012.