"We're thinking maybe we'll get married," she told E! Online.
Tomlin, who celebrates her 74th birthday Sept. 1, said she never expected to see gay marriage become possible. Now, she thinks it would be a good step after 42 years with Wagner, 78.
"You don't really need to get married, but marriage is awfully nice," she said. "Everybody I know who got married, they say it really makes a difference. They feel very very happy about it."
In 1971, Tomlin, impressed by an after-school television special Wagner wrote, invited her to collaborate with her. Over the years, their partnership has included working together on movies and television specials.
Tomlin said a formal wedding is not in the cards: "No rings, no bridal dresses. Maybe we'll be dressed like chickens."