United States's Matt Mellin lost 8-4 to United States's Daniel Bliven in the Final of the USA Curling 5-Under National Championship, held April 20 - 23, 2023 in Duluth, Minnesota. To advance to the championship game, United States's Matt Mellin won 7-4 over United States's Nathan O'Reilly in the semifinals of the 2023 USA Curling 5-Under National Championship in Duluth, Minnesota; and won 12-8 over United States's David Dickinson in the quarterfinals. of the 2023 USA Curling 5-Under National Championship in Duluth, Minnesota;
 
United States's Matt Mellin finished 4-1 in the 0-team qualifying round. . In their opening game, United States's Matt Mellin defeated United States's Matthew Kenlan 8-5, then won 8-7 against United States's Josh Newborn and 6-3 against United States's Will Meyer. United States's Matt Mellin went on to lose 7-5 against United States's Austin Swoboda. United States's Matt Mellin responded with a 8-4 win over United States's Elizabeth Brown in their final qualifying round match.
 
United States's Matt Mellin ranks th overall on the Year-to-Date rankings with points earned so far this season.