Following the show's end in 1975, Klugman extended his talents in another high-rated show called Quincy, M.E.
Klugman was also an avid horseracing fan, and owned a racehorse was named after him, Jacklin Klugman.
In the 1980s, he lost his voice to cancer, but he managed to train himself to talk again.
He counted his Odd Couple co-star Tony Randall among his closest friends.
From the obituary:
Throat cancer took away his raspy voice for several years in the 1980s. When he was back on the stage for a 1993 revival of "Three Men on a Horse," The Associated Press review said, "His voice may be a little scratchy but his timing is as impeccable as ever."
"The only really stupid thing I ever did in my life was to start smoking," he said in 1996. Seeing people smoking in television and films, he added, "disgusts me, it makes me so angry -- kids are watching."
In his later years, he guest-starred on TV series including "Third Watch" and "Crossing Jordan" and appeared in a 2010 theatrical film, "Camera Obscura."
Klugman's hobby was horse racing and he eventually took up raising them, too.
"I always loved to gamble," he said. "I never got close to a horse. Fate dealt me a terrible blow when it gave me a good horse the first time out. I thought how easy this is.
Among his most memorable television appearances were those he was featured in The Twilight Zone. In this interview, Klugman talks about it and Rod Serling: