After signing, Altavilla made his professional debut that same year with the Everett AquaSox and spent the whole season there, going 5–3 with a 4.36 ERA in 14 starts. In 2015, he played for the Bakersfield Blaze where he pitched to a 6–12 record with a 4.07 ERA and 1.29 WHIP in 28 games started. He began 2016 with the Jackson Generals.
Altavilla was called up to the majors for the first time on August 27, 2016,[3] and he made his major league debut that same night. In 43 relief appearances for Jackson prior to being recalled, he was 7–3 with 1.91 ERA. He spent the remainder of the season with Seattle, compiling a 0.73 ERA in 12.1 innings pitched.
Altavilla began 2017 with Seattle, but was sent down to the Tacoma Rainiers in April. He was recalled from Tacoma multiple times during the season before being recalled for the remainder of the season for September call-ups. In twenty games for Tacoma he was 2–0 with a 1.54 ERA, and in 41 games for Seattle, he was 1–1 with a 4.24 ERA.[4] Altavilla began 2018 with Seattle but was placed on the disabled list in late April with joint inflammation. After being activated on May 12, he returned to Seattle, but was sent back down to Tacoma on May 23. He was recalled once again on May 27. He was limited to just 22 appearances in 2018 and 17 in 2019 due to injury and inconsistency.
On July 29, 2020, Altavilla recorded his first career save in a 10–7 win over the Los Angeles Angels.[5]
On April 17, 2021, Altavilla was placed on the 10-day injured list with right elbow inflammation.[7] Through 2 games, Altavilla recorded a 6.75 ERA. He was later transferred to the 60-day injured list on May 28.[8] On June 29, Altavilla underwent Tommy John surgery, ending his 2021 season.[9] On November 3, the Padres outrighted him to Triple-A.[10] That same day, Altavilla elected free agency.[11]
Boston Red Sox
In mid-March 2022, Altavilla was reported to have agreed to a two-year minor-league deal with the Boston Red Sox;[12] the signing was confirmed by the team on March 30.[13] He did not make an appearance for the organization in 2022 as he continued to rehabilitate from surgery.
In 2023, Altavilla made 8 appearance split between the rookie–level Florida Complex League Red Sox and High–A Greenville Drive, posting a cumulative 3.00 ERA with 7 strikeouts in 12.0 innings of work. On August 15, Altavilla was released by the Red Sox organization.[14]
Kansas City Royals
On December 6, 2023, Altavilla signed a minor league contract with the Kansas City Royals that included an invitation to spring training.[15] In 24 games for the Triple–A Omaha Storm Chasers, he recorded a 2.63 ERA with 30 strikeouts and 3 saves across 27+1⁄3 innings pitched. On June 10, 2024, the Royals selected Altavilla's contract, adding him to their active roster.[16] Two days later, he made his first start for the Royals, allowing six runs in the first inning before being relieved of duties after recording one out. Altavilla was placed on the injured list with a right oblique strain on June 20,[17] and transferred to the 60–day injured list on July 5.[18] On September 5, the team activated Altavilla from the IL, and subsequently designated him for assignment.[19] He cleared waivers and was sent outright to Omaha on September 7.[20] Altavilla elected free agency on October 2.[21]
Chicago White Sox
On December 12, 2024, Altavilla signed a minor league contract with the Chicago White Sox.[22]