Justin Ross (Courtesy Justin Ross.)

“It’s a part-time legislature, but I don’t want to be a part-time father,” Ross (D-Prince George’s) said in an interview. “I’m looking forward to spending more time with my family.”

Ross, 36, has been a House member for a decade and has served since 2007 as the chamber’s chief deputy majority whip. The title understates the importance of the role he has played in recent years helping round up votes for key pieces of legislation.

During the past year alone, those have included bills to legalize same-sex marriage and to expand Maryland’s gambling program to include a Prince George’s casino. Both measures will appear on the November ballot.

“Justin has been an invaluable part of my leadership team,” House Speaker Michael E. Busch (D-Anne Arundel) said in a statement. “He has been critical to the passage of every piece of important legislation in the House of Delegates over the past six years.”

Senate President Thomas V. Mike Miller Jr. (D-Calvert) said in a statement that he was “truly saddened” to learn of Ross’s decision.

Though Ross attributed his decision to leave mid-term to his family and business situations, some colleagues noted that other leadership opportunities in the House have been limited. That is due in part to several veteran committee chairmen whose continued service in the chamber has limited upward movement among younger delegates.

Ross represents a district in Prince George’s County that includes Hyattsville and Greenbelt.

He is currently vice president of the AFL-CIO Investment Trust Corp., which manages a $2.3 billion commercial real estate fund. Ross said he will continue to work in the commercial real estate investment arena while exploring new business consulting opportunities.

“Representing my hometown for the last decade has been a dream come true,” Ross said. “I am grateful to Prince George’s County for giving me this incredible opportunity and I am proud of the historic votes that I have been a part of.”

By law, the Prince George’s County Democratic Central Committee will have 30 days to recommend a replacement for Ross to Gov. Martin O’Malley (D).

Ross’s retirement is effective Nov. 9.