Mandated child abuse reporters may judge specific disciplinary practices as unacceptable for young children, whereas child law professionals arbitrating allegations may be less inclusive. Do the views of these groups diverge, by child age, regarding discipline? Judgments of community norms across a wide range of children's ages were obtained from 380 medical and legal professionals. Because the Parent-Child Conflict Tactics Scale (PC-CTS) can be used to assess the epidemiology of child disciplinary behaviors and as a proxy to examine the incidence or prevalence of child abuse, the disciplinary practices described on the PC-CTS were presented as triggers for questions. Significant child age effects were found for disciplinary practices classified as "harsh." The consistencies between legal and medical professionals were striking. Both groups reflected changes in United States norms, as non-physical approaches were the most approved. We conclude that instruments estimating the prevalence of child maltreatment by parent-report should consider modifying how specific disciplinary practices are classified. Copyright © 2016 John Wiley & Sons, Ltd.