Brosmer was named the New Hampshire Wildcats' starting quarterback entering his freshman season.[2] He completed 183 of 311 pass attempts for 1,967 yards with 12 touchdowns and 12 interceptions.[3] UNH played one game during Brosmer's true sophomore season, which was postponed from late 2020 to the spring of 2021 due to the COVID-19 pandemic. He tore his ACL during preseason practices the following year and missed the entire season.[4] Brosmer passed for 3,157 yards with 27 touchdowns with eight interceptions as a junior.[5] As a senior, he led the NCAA Division I Football Championship with 3,464 passing yards and had 29 passing touchdowns.[6] After the season, he entered the NCAA transfer portal and utilize the extra year of eligibility granted to college athletes who played in the 2020 season due to the coronavirus pandemic.[7]