PITI is the borrower's monthly costs for principal, interest, property taxes, and homeowner's insurance. PITI reserves are the amount of cash that a borrower has to prove to the lender that is available to cover monthly PITI, after the borrower has covered the down payment and closing costs on a purchase loan or the closing costs on a refinance loan. PITI reserve requirements vary from lender to lender. Some lenders do not require any reserves on a loan for a primary residence. Lenders often require six months of reserves for a non-owner-occupied home.