Inadmissibility waivers are used when an individual has not yet been admitted to the United States and who is ineligible to be admitted to the United States as an immigrant or to adjust status in the United States. Some factors creating the inadmissibility include those related to health, criminal activity, security violations and illegal entries. The requirements for the waiver depend upon the grounds for inadmissibility, and Form I-601 is necessary to seek this waiver.