M. Justin Baum, who worked in advertising in the Washington area for more than four decades, died Dec. 28 at his home in Bethesda. He was 93.

The cause was complications from dementia and congestive heart failure, said his son, Bobby Baum.

Mr. Baum retired in the early 1990s after a decade as an advertising consultant. He had previously been a sales manager at the Washington Star newspaper and an advertising manager with Lansburgh’s department stores. He began his career working for advertising agencies including the Ernest S. Johnston Agency, where he was an account executive.

M. Justin Baum was born in the District, where he graduated from Western High School in 1937 and attended Wilson Teachers College. He served in the Army Air Forces during World War II and received a bachelor’s degree in business administration from American University in 1955.

His wife of 53 years, Doris Hjort Baum, died in 2007. Survivors include his son, Bobby Baum of Bethesda.

— Emily Langer