He began serving the remaining seven months of Humason's House term and campaigned for a first full-term in the regular November election, defeating Allie in a rematch.

On November 8, 2019, Velis announced his candidacy for the Massachusetts Senate's 2nd Hampden and Hampshire district seat following his predecessor Donald Humason Jr.'s election as Mayor of Westfield.

[7] On May 19, 2020, with the election delayed by the COVID-19 pandemic, Velis won the Senate seat over Cain with 64 percent of the vote, becoming the first Democrat in 25 years to represent the 2nd Hampden and Hampshire district.

Velis enlisted in the United States Army Reserve in 2011 and is currently serving in the Judge Advocate General (JAG) Corps as part of the 3rd Legal Operations Detachment.

[15] Velis cosponsored Bill H.4200 with Representative John Scibak, a petition relative to the scheduling of high school athletic contests.

Bill H.4047 would also create a special commission to look at state policies dealing with individuals with autism, and allow families to set aside money tax free in savings accounts to pay and plan for the long-term care and housing of children with intellectual disabilities.

Under the measure, people convicted of first-degree murder for crimes that occurred while they were between the ages of 14 and 18 could be eligible for parole after serving 20 to 25 years in prison.

[20][21] Velis has cosponsored Docket HD4311 with Representatives Diana DiZoglio and Jonathan Zlotnik, otherwise known as An Act Relative to the Taxation of Inventory in Manufacturing.

According to DiZoglio, the bill is designed to gradually eliminate the inventory tax manufacturers pay on raw materials over a period of four years.