To understand what hiring managers mean when they say this, and how you can get around it, put yourself in the manager's head. When a manager says you're overqualified, here's what she's thinking:
So your job is to reassure the hiring manager that none of these things are true, and in order to be convincing, you need to explain why. For instance:
Ideally, the time to address all of this is in your cover letter. Otherwise, you may never get the chance to say it at all, because the manager may simply assume that you don't understand the nature of the position and screen you from the start. And once you get to the interview stage, be prepared to discuss it again, likely in more detail.
If you can successfully put these doubts to rest, many hiring managers will be thrilled to hire your overqualified self. After all, you're a bargain.
Alison Green is chief of staff for a medium-size nonprofit , where she oversees day-to-day management of the staff, as well as hiring, firing, and staff development. She is working with the Management Center to coauthor a book on nonprofit management. Her writings have been published in the Washington Post, the New York Times, Maxim, and dozens of other newspapers. She blogs at Ask a Manager.