He also spent a year as a full-time volunteer building a transitional housing program for homeless women in San Antonio, Texas, where he met his wife, Serra Sippel, also a native Washingtonian and president of the Center for Health and Gender Equity.

[7][8] He worked as Chief Counsel to Congresswoman Eleanor Holmes Norton[1] and was a vice president of public policy for health insurance carrier CareFirst for several years.

In accordance with the District's Home Rule Act, one of the seats up for election that year was reserved for an individual who is not affiliated with the Democratic Party.

[10] During a debate among the four candidates for the at-large council seat, Grosso supported expanding the types of illnesses that qualify for medical marijuana.

[18] During Council Period 20 (his first two years in office), Grosso served on the following committees: Business, Consumer and Regulatory Affairs; Education; Finance and Revenue; Health; and Transportation and the Environment.

[21] In 2013, as a member of the council's Committee on Education, Grosso sponsored a measure on school suspensions and expulsions that was added to the Attendance Accountability Amendment Act of 2013.

Fellow Councilmember Mary Cheh criticized Grosso's vote, characterizing it as a favor to health insurance companies.

[27] On his first year on the council, Grosso introduced the Expedited Partner Therapy Act of 2013 in an effort to reduce the spread of sexually transmitted infections.

[40] As a result of his work on this bill, Councilmember Grosso sought to stop the practice of shackling youth during their appearances in juvenile court.

[71] The budget allocated $1.6 million for a new literacy intervention program, targeted at 3rd grade reading and writing success, and restored $760,000 in funding to the University of the District of Columbia.

[72] The Budget Support Act broadened the scope of the Bullying Prevention Taskforce and extended its term until August 2018.

[74] Following the departure of school chancellor Antwan Wilson, Grosso announced that he would investigate the controversial preferential student placement that lead to his resignation.

Three days later, following a visit from counsel to Mayor Bowser, Mark Tuohey, Grosso changed his mind and said that he would not hold a hearing, stating that the committee's efforts were better focused elsewhere.

[75] In October 2018, Grosso voted to repeal Initiative 77, a referendum passed by the majority of DC voters months earlier that would phase out a tipped minimum wage.

[77] A report by Public Citizen revealed that Grosso had accepted more than $10,000 in payments from restaurant-related interests opposed to Initiative 77.

[78] In July 2019, Grosso was the first member of the DC Council to call for Jack Evans' resignation following revelations about his outside employment.

[79] In November 2019 he announced that he would not run for reelection, citing a need to live out his belief that Councilmembers should not serve more than two terms and that he wanted to encourage a new generation of progressive activists.

[81] Following the arrest of New Jersey priest Scott Asalone on charges of sexually abusing a teenager in Loudoun County, Virginia in 1985,[82] Grosso publicly came forward as the one who was sexually abused by Asalone and issued a statement claiming that "The minor he assaulted was me.”[83][82] Official results from the District of Columbia Board of Elections:[17]