FDA has published guidance to assist sponsors preparing to submit abbreviated new drug applications (ANDAs) and prior approval supplements (PASs) to ANDAs for which the applicant is seeking approval of a new strength of the drug product. The guidance describes what should be included in an ANDA and highlights serious deficiencies that may cause FDA to refuse to receive an ANDA. A refuse-to-receive decision indicates that FDA has determined that an ANDA is incomplete on its face, usually because of omissions.