According to our lecture by Susan M. Hadley MPH* on domestic violence, it mandatory to report child and elder abuse. All health care providers can report if they suspect a person is being abused. They are protected under the law if they "report in good faith & exercise due care."
Ms. Hadley also stated that reporting requirements for IPV vary by jurisdiction and states and should be checked with the state attorney general.
*Hadley MPH, Susan M. "Domestic Violence: The Health Provider's Response." PubH 6123. University of Minnesota, Minneapolis. 22 Mar. 2010. Lecture.