PITI stands for Principal, Interest, Taxes, and Insurance — the four components of a complete monthly mortgage payment in the USA. Principal is the portion reducing your loan balance, interest is the lender's fee, taxes are your monthly property tax escrow, and insurance covers homeowners insurance. Lenders use your total PITI payment to calculate your debt-to-income ratio.

Private Mortgage Insurance (PMI) is required on conventional US mortgages when the down payment is less than 20% of the purchase price, resulting in a Loan-to-Value (LTV) ratio above 80%. PMI typically costs 0.5%–1.5% of the loan amount annually and can be cancelled once your LTV reaches 80% through principal repayment or home value appreciation.

The minimum down payment for a US mortgage varies by loan type: conventional loans require as little as 3% down (5% for most lenders), FHA loans require 3.5% down with a credit score of 580+, VA loans require 0% down for eligible veterans and active military, and USDA loans require 0% down for eligible rural properties. Lower down payments require PMI or the equivalent government insurance premium.

You can request PMI cancellation once your loan balance drops to 80% of the original home purchase value. Legally, the lender must automatically terminate PMI once your balance drops to 78%. You can also order a new appraisal to prove your home has appreciated enough to put your LTV under 80%.

Your DTI ratio compares your monthly debt payments (including PITI) to your gross monthly income. Lenders check two ratios: front-end DTI (housing costs only, limit ~28%-31%) and back-end DTI (all monthly obligations like credit cards and auto loans, conventional limit ~43%-45%, FHA up to 50%).

The US market primarily uses 30-year and 15-year fixed-rate mortgages, where the rate remains constant for the entire term. Adjustable-Rate Mortgages (ARMs), such as 5/1 or 7/1 ARMs, offer a lower introductory rate for 5 or 7 years before adjusting annually based on inflation indexes.