This forum and the Reddit forum are made up of Peace Corps Volunteers and people seeking those positions. It looks like you are seeking employment through PC, and that is a completely different process from what we are familiar with.
Human Resources cannot discriminate against you based on your health status, so it shouldn't affect a job offer. If you are applying for an overseas position, they may require a medical screening to ensure you are fit for service, and then the only time your health would affect your employment is if they believed your health condition would prevent you from being able to perform essential job functions or if you would be unable to receive your treatment wherever you are posted. As far as healthcare goes, you will be a federal employee, so you will receive federal health insurance, but Peace Corps will not be your healthcare provider.