Urbanization can affect ecological dynamics and wildlife health, especially in parasite-host interactions. House finches (Haemorhous mexicanus) inhabit urban, suburban, and rural environments and are susceptible to vector-borne haemosporidian parasites (Plasmodium, Haemoproteus, and Leucocytozoon). In our study system, blood smear analysis revealed that house finches in suburban and rural habitats have higher haemosporidian prevalence and parasitemia than urban habitats, but the distribution of specific parasite variants remains unknown. We aim to genetically characterize haemosporidian lineages along three categories of urbanization. We hypothesize that haemosporidian diversity will differ by habitat, with distinct variants emerging in urban, suburban, and rural areas. Specifically, we will amplify the Cyt-b gene from roughly 87 positive samples using nested polymerase chain reaction (PCR). Sequencing is currently underway. We will check sequence quality with Geneious and identify variants with BLASTn, followed by haplotype networks and statistical analyses in R. Ultimately, this research will offer insight into whether urbanization shapes the distribution and diversity of avian haemosporidian parasites and to better understand how environmental change influences parasite lineage distribution. This project helps conservation efforts and may help guide urban planning to promote biodiversity and contribute to understanding how parasite-host dynamics are altered at the human-wildlife interface.