Q. How do I handle multiple authors in APA format for an in-text citation?

There is a table on page 177 of the APA Manual on how to handle multiple authors for in-text citations. In most cases you would simply list the author names. If you include the names in the phrasing of your sentence you would make sure to write out the word "and." If you just use the parenthetical format you would use an "&" in your list of names.

For example

Gossett, Stephan, and Marrall (2011) examined ways in which an academic library might record reference statistics.

Or

Librarians have examined best practices for recording reference statistics in the past (Gossett, Stephan, & Marrall).