Delegate since 2015 and majority leader. Moon has represented District 20 since 2015 and became House majority leader in 2023.
- Judiciary Committee member and subcommittee chair. He serves on the Judiciary Committee, chairs the Criminal Law & Procedure Subcommittee and previously served as vice‑chair.
- Chairs consent calendars and federal action committees. Moon leads the Consent Calendars Committee and the Joint Federal Action Oversight Committee.
- Member of audit, rules and policy committees. He sits on the Joint Audit & Evaluation Committee, Rules & Executive Nominations Committee, Legislative Policy Committee and Spending Affordability Committee.
- Chair of Asian‑American caucus and co‑sponsor of HB0837. Moon chairs the Maryland Legislative Asian‑American & Pacific‑Islander Caucus and co‑sponsored the More Opportunities for Career‑Focused Students Act.
- Advocates for election reform, police accountability and education equity. His legislative priorities include open government, affordable housing and equitable access to education.