How Does Private Mortgage Insurance (PMI) Work?
A smaller down payment can get a buyer into a home sooner, but it often comes with an extra monthly line item most people haven’t budgeted for: private mortgage insurance.
The short answer
Private mortgage insurance, or PMI, is a monthly, or sometimes upfront, charge added to a conventional mortgage when the down payment is below a certain threshold, commonly discussed as 20% of the home’s price. It protects the lender, not the borrower, against loss if the loan isn’t repaid. PMI typically ends once enough equity has built up, either automatically or by request, depending on the loan terms and payment history.
Who it applies to
PMI generally applies to conventional loans, those not backed by certain government programs, when the down payment falls below the lender’s threshold for waiving it. The specific percentage and cost vary by lender, loan type, and borrower credit profile, and government-backed loan programs have their own separate insurance-like requirements with different rules, so the details depend heavily on the loan a borrower actually gets.
How it affects the payment
PMI is usually added as its own line to the monthly mortgage payment, on top of principal, interest, taxes, and insurance collected through an escrow account. The cost is generally expressed as a percentage of the loan amount per year, divided into monthly installments, and it tends to be higher for borrowers with a smaller down payment or a lower credit score, since it reflects the lender’s assessment of risk, the same underlying logic that shapes credit scores more broadly. Over the life of a loan, PMI can add up to a meaningful sum, which is part of why it’s worth understanding rather than treating as a fixed, unavoidable cost.
When it goes away
PMI isn’t usually permanent. Once the loan balance drops to a certain percentage of the home’s original value, often through a combination of scheduled payments and, sometimes, rising home values, a borrower can typically request cancellation, and many loans require automatic cancellation at a later equity threshold regardless. The exact rules depend on the loan agreement and applicable regulations, which is worth confirming directly with the loan servicer rather than assuming.
PMI compared with the alternative
The alternative to paying PMI is usually a larger down payment, commonly 20%, that clears the threshold entirely. That trade-off is a real one: a bigger down payment ties up more cash upfront, potentially cash that could otherwise support saving for a down payment goals elsewhere, in exchange for avoiding an ongoing monthly cost. Some borrowers instead choose a smaller down payment and treat PMI as the price of buying sooner rather than waiting years to save more, particularly if home prices or rents are also moving during that wait. Neither choice is right for everyone; it depends on cash on hand, other goals, and how the numbers compare over the expected time in the home.
What to weigh
PMI is a cost that exists specifically to bridge a gap in down payment size, and it’s structured to eventually disappear as equity builds. Understanding when it applies, how it’s calculated, and the process for removing it turns PMI from a mysterious fee into a predictable, temporary part of the loan.