Jane Fonda, meanwhile, says they're still 'waiting for the script.'
The 79-year-old actress talked about the long-rumored film during the Grace and Frankie panel at PaleyFest in Los Angeles on Saturday, teasing that while there's "hope" surrounding the project, these things take time.
It's been nearly 40 years since the release of 9 to 5, starring Tomlin, Fonda and Dolly Parton, which quickly became a classic after it premiered in 1980. Though a sequel has been talked about for years, it's been difficult to line up all three actress' schedules -- Tomlin and Fonda revealed at Saturday's panel that they're having the same problem while trying to get Parton to guest star on Grace and Frankie.
ET's Brice Sander spoke to Tomlin and Fonda on the red carpet about the project.
"A script is being written and we’ll see," Tomlin said. "You never know."
As for getting Parton to guest star on Grace and Frankie, Fonda noted, "She's so busy. ... She’s had the 9 to 5 musicals in London and she went over for that."
Still, Tomlin noted that they've "come very close" to getting Parton to guest star, and that the country music legend really wants to do it.
During the PaleyFest panel, Fonda echoed that they were all waiting for the 9 to 5 script.
"Everybody is very hopeful. We may not live to see it," Tomlin also cracked.
Parton said that she, Tomlin and Fonda had all signed on for the 9 to 5 follow-up during an interview with ABC News' Nightline last year.
"All these years we've talked about doing a sequel to 9 to 5, but it never made any real sense," Parton shared. "Until just recently [with] all the equal work for equal pay and all the harassment in the workplace [backlash] -- we decided that we are going to try to do another one."
"We're trying to get the script and all that. Everybody is very interested, and we've all agreed that we'd love to do it, if it's right," she revealed.
While 9 to 5 -- and Parton's guest-starring role on Grace and Frankie -- is still up in the air, Tomlin and Fonda had no problem spilling details about the Netflix series' upcoming sixth season.
The show will find Fonda's Grace and Tomlin's Frankie embarking on a new business venture. "And it has to do with the lower part of our bodies," Fonda teased.
As for Martin Sheen and Sam Waterston's characters, Sheen said of the pair's romance: "The overriding thing between our characters we really cannot talk about right now."
See more on Grace and Frankie in the video below.
Reporting by Philiana Ng.