Filing closed on March 14 for candidates running in the District of Columbia primary. Three parties have their own primaries: Democratic, Republican, and Green. No Republican filed for Delegate to the U.S. House. See the list here.
D.C. defines a “political party” as a group that got at least 7,500 votes for one of the partisan districtwide offices (excluding shadow U.S. Senate and shadow U.S. House). Because there will be no Republican running for Delegate to the U.S. House in November, it should be fairly easy for any party that is not now ballot-qualified to run for Delegate, and to expect to receive 7,500 votes. In 2012, when the Republicans also ran no one for Delegate, the Libertarian nominee, Bruce Majors, got 16,524 votes and gave the Libertarians party status. However, in 2014, a Republican did run for Delegate, and no Libertarian ran, and the Libertarian Party lost its party status.