He was in private practice in Norfolk from 1894 to 1910, and from 1913 to 1921, serving as the United States Attorney for the Eastern District of Virginia from 1910 to 1913.

His service terminated on March 3, 1931, due to his elevation to the Court of Appeals of the District of Columbia.

[1] Groner was nominated by President Herbert Hoover on January 5, 1931, to the Court of Appeals of the District of Columbia (United States Court of Appeals for the District of Columbia from June 4, 1937), to a new Associate Justice seat authorized by 46 Stat.

His service terminated on December 7, 1937, due to elevation to Chief Justice of the same court.

[1] Groner was nominated by President Franklin D. Roosevelt on November 26, 1937, to the Chief Justice seat on the United States Court of Appeals for the District of Columbia (Judge of the United States Court of Appeals for the District of Columbia Circuit from June 25, 1948) vacated by Chief Justice George Ewing Martin.