Developed by the National Institute of Allergy and Infectious Diseases (NIAID), in conjunction with the NIH Office of Laboratory Animal Welfare (OLAW), this tutorial provides a step by step guide to the preparation of an application and covers such topics as considering alternatives, obtaining assurances and Institutional Animal Care and Use Committee (IACUC) approval, Just-In-Time processes, NIH review of animal subjects applications, grant awards, IACUC monitoring of awards, and reporting requirements.  Although designed specifically for NIAID applicants, the information is relevant to any investigator submitting an application to the NIH for an activity involving animals.