There have been a dozen or more reunions, of the Brady Bunch cast, but is The Brady Girls Get Married movie the only time the whole cast returned intact? I can't think of any other time all 9 original cast members were together.

Neither can I. Anyone????

I think that's official

the brady girls get married was the only time all of the cast returned each of the girls were each recast in one brady reunion
maureen mccormick was replaced by leah ayres in the bradys 1990
eve plumb was replaces by geri reischl in the brady bunch our 1977
and susan olsen was replaced by jennifer runyon in a very brady christmas 1988

Off-screen, they were all at Maureen McCormick's wedding.