A down payment is the initial amount paid when buying a home, with minimums set at 5% for homes up to $500,000, 5% on the first $500,000 plus 10% on the remainder up to $1 million, and 20% for homes $1 million or more. Down payments under 20% require mortgage loan insurance, with premiums from 0.6% to 4.5%. Larger down payments lower mortgage size, insurance costs, and total home cost.