Q. In author-date, how does one handle multiple forthcoming works by a single author? Does one use forthcominga, forthcomingb, etc.? Or maybe with a hyphen: forthcoming-a, forthcoming-b?
A. We like your second suggestion:
Smith, Jarell. Forthcoming-a. Title of First Work. City: Publisher.
Smith, Jarell. Forthcoming-b. Title of Second Work. City: Publisher.
These would then be cited in the text as (Smith, forthcoming-a) and (Smith, forthcoming-b). Normally there’s no comma between the author’s name and the date of publication in Chicago style—(Smith 2022a)—but we do make an exception in this case (as noted in CMOS 15.45).