This paper examines the role of older Americans in the U.S. housing market. First, using data from the Census and the Survey of Consumer Finances (SCF), I document a long-term increase in mortgage leverage among older households. Second, I argue that the combination of declining interest rates and looser mortgage origination standards has relaxed the payment-to-income (PTI) constraint, allowing households to take on mortgage debt later in life despite having limited income. I provide empirical support for this mechanism using Home Mortgage Disclosure Act (HMDA) data and regional variation in exposure to the adoption of automated underwriting in the 1990s. Finally, I develop a numerical lifecycle model to analyze the implications for aggregate house prices and intergenerational wealth distribution.