How old is too old to be a father? Can you be a little bit older or "old-ish" to be a dad without being considered an "older dad"? At some point, does one simply become too old to be a father? Unless a man requires medical assistance in family building, that answer has historically turned solely on his opportunity to have a willing female partner of reproductive age. As with so many other aspects of family building, assisted reproductive technologies have transformed the possibilities for-and spawned heated debates about-maternal age. Much attention has been given to this contentious topic for potential mothers, with many programs putting age-related limitations in place for their female patients. This article considers whether there should also be limits-and how we should approach that question-for men who require and seek medical assistance to become fathers.