The original main cast members of Mary Tyler Moore (1970-1977) have all died, but as many on social media argue, Betty White, who hits age 100 in January, should count as a main cast member, if not an original one. White became a memorable part of the series, yet was on just 45 of 168 episodes, debuting in Season 3.
Either way, MTM's most prominent cast members largely had fairly long lives compared to many other series. Of the main cast members — by any reasonable definition —most of the main cast achieved 80, if not 90:
Betty White, 99 and still with us — 45 episodes as Sue Ann Nivens
Cloris Leachman, 94 (1926-2021) — 35 episodes as Phyllis Lindstrom
Ed Asner, 91 (1929-2021) — 166 episodes as Lou Grant
Gavin MacLeod (1931-2021) — 168 episodes as Murray Slaughter
Mary Tyler Moore, 80 (1936-2017) — 168 episodes as Mary Richards
Valerie Harper, 80 (1939-2019) — 92 episodes as Rhoda Morgenstern
Georgia Engel, 70 (1948-2019) — 57 episodes as Georgette Franklin
Ted Knight, 62 (1923-1986) — 165 episodes as Ted Baxter
For purists who want to include actors who had prominent recurring roles, the great news is there are still three with us:
Joyce Bulifant, 83 — 11 episodes as Murray Slaughter's wife Marie
John Amos, 81 — 14 episodes as weatherman Gordy Howard
Lisa Gerritsen, 63 — 10 episodes as Phyllis Lindstrom's daughter Bess
Other actors who recurred did so with fewer than 10 episodes. They include, living:
Larry Wilde, 93 — 5 episodes as an emcee
Gino Conforti, 89 & still with us — 2 episodes as Roy
Jack De Mave, 85 & still with us — 2 episodes as Armond
Beverly Sanders, 81 & still with us — 3 episodes as a waitress
J. Benjamin Chulay, 69 & still with us — 2 episodes as Pete
Robbie Rist, 57 & still with us — 3 episodes as Ted & Georgette's adopted son David
As for actors who recurred with fewer than 10 episodes who are no longer with us:
Nanette Fabray, 97 (1920-2018) — 2 episodes as Dottie, Mary's mom
Jack Manning, 93 (1916-2009) — 2 episodes as a maitre d'
Dick Balduzzi, 91 (1928-2020) — 2 episodes as Philly, 1 more as another character
John Gabriel, 90 (1931-2021) — 5 episodes as Mary's date Andy
Irene Tedrow, 87 (1907-1995) — 2 episodes as Congresswoman Margaret Geddes
Harold Gould, 86 (1923-2010) — 2 episodes as Rhoda's dad Martin Morgenstern
Richard Schaal, 86 (1928-2014) — 3 episodes as Howard/Paul Arnell (2 others as other characters)
Jerry Van Dyke, 86 (1931-2018) — 2 episodes as Wes Callison
Michael Tolan, 85 (1925-2011) — 3 episodes as Dan Whitfield
Eileen Heckart, 82 (1919-2001) — 3 episodes as Flo
Bill Quinn, 81 (1912-1994) — 3 episodes as Mary's dad Walter
Steve Franken, 80 (1932-2012) — 2 episodes as Jonas Lasser
Patrick Campbell, 78 (1924-2003) — 4 episodes as an announcer
Penny Marshall, 75 (1943-2018) — 2 episodes as Paula Kovacs, 1 more as another character
Robert Rothwell, 75 (1930-2006) — As the station's floor manager
David Ogden Stiers, 75 (1942-2018) 3 episodes as Mel Price
Sheree North, 73 (1932-2005) 2 episodes as Charlene Maguire
Phillip R. Allen, 72 (1939-2012) 2 episodes as Gus Brubaker
Nancy Walker, 69 (1922-1992) — 4 episodes as Ida Morgenstern
Priscilla Morrill, 67 (1927-1994) — 5 episodes as Lou's estranged wife Edie
Ted Bessell, 61 (1935-1996) — 2 episodes as Joe Warner
Barbara Colby, 36 (1939-1975) — 2 episodes as Sherry
You forgot Henry Winkler as Mary’s date! STILL LIVING AND GIVING THE THUMBS UP!!!!