Kaplan was born in Brooklyn, New York, in 1927, the son of Dr. I.E. Kaplan and his wife. He attended Public School 16, and Junior High School 15 and graduated from Eastern District High School in 1943. He graduated from Brooklyn College with a bachelor's degree in English in 1947 and later took classes in theater at the University of Southern California.
Kaplan's first film role was as a court reporter in Adam's Rib (1949). He had a small role in the 1963 film It's a Mad, Mad, Mad, Mad World playing a gas station attendant. He co-starred in the 1965 comedy The Great Race. He also made a brief appearance as a carpet cleaner in the 1976 film Freaky Friday.
Kaplan had a regular role in the radio sitcom and later television version of Meet Millie as Alfred Prinzmetal, an aspiring poet-composer. The program ran from 1951–54 on radio and continued on television from 1952–56.
In addition, the actor was the voice of Choo-Choo on the 1960s cartoon series Top Cat. In 1969, he appeared as Stanley on Petticoat Junction in the episode: "The Other Woman".
Kaplan is probably best known for his recurring role on the sitcom Alice where he portrayed a phone lineman named Henry Beesmeyer who frequented Mel's diner. He was with the cast from 1977 until the series ended in 1985.
He joined the California Artists Radio Theatre In January 1984 and performed leading roles in over twenty 90 minute productions. He created two musicals for the group and one."A Good House For A Killing" is a successful Musical Comedy. He appeared in CART's Alice in Wonderland as the White Rabbit,:And In Norman Corwin's Plot to Overthrow Christmas with CART, as Nero's messenger opposite David Warner. He Was in CART's Bradbury 75th Birthday Tribute. He played opposite Jo Ann Worley in three CART productions :Corwin's 100th Birthday, Chekhov's Humoresque and in The Man With Bogart's Face" he was the Cowardly Lion in Cart's Wizard of Oz opposite Norman lloyd and Linda Henning. And was the Lead in"Clarence" opposite Samantha Eggar and Janet Waldo.: and Dr.Einstein opposite David Warner in Cart's Arsenic and Old Lace..He served on the Board for California Artists Radio Theatre for 32 years.
In 1987, he reprised his role of Choo-Choo for Top Cat and the Beverly Hills Cats. At the same time, he actively returned to voice-over acting, playing roles in shows such as Garfield and Friends, Aaahh!!! Real Monsters, Johnny Bravo, and most recently, The Garfield Show in 2011. Kaplan was the commercial spokesperson for the American cologne Eau de Love. In addition to his role on Alice, he played Mr. Gordon on Becker alongside Ted Danson.
Kaplan died of natural causes in his sleep on August 25, 2016. He was 89.
