“This publication provides an introduction to mandatory reporting laws, and how these laws can help corrections officials respond to sexual abuse in custodial settings, both offender-on-offender and staff sexual misconduct. The importance of mandatory reporting laws cannot be overstated, given recent scandals involving the abuse of vulnerable populations, including youth. This publication provides insight into the utility of mandatory reporting laws, in light of the enactment of the Prison Rape Elimination Act of 2003 (PREA).” Sections comprising this paper are: introduction; background-the Prison Rape Elimination Act (PREA) of 2003; mandatory reporting and juveniles-who a juvenile is, who the mandatory reporter is, what the standard of proof is, and consequences of failing to report; mandatory reporting and vulnerable persons-who a vulnerable person is, who the mandatory reporter is, what the standard of proof is, and consequences for failing to report; bringing correctional settings in line with state mandatory reporting requirements-reporting procedures, and other issues to consider such as what to report and retaliation; and conclusion.