Cryptosporidium is a pathogenic intestinal parasite that causes cryptosporidiosis, a diarrheal disease common in the US. The predominant species infecting humans are C. hominis and C. parvum. These species can be further classified into families and subtypes by analyzing the sequence of the 60-kDa glycoprotein (gp60) gene. Currently, there are no data available regarding the families and subtypes of Cryptosporidium found in New York State (NYS) or their distribution within the state.