The Mortgage Borrower Who Can’t Fail and the One Who Can’t Win

This is the third in a series of four posts that explore the challenges potential homebuyers face when seeking a mortgage loan.

Consider two mortgage applications filed on the same day in 2024.

The first is from a household earning $235,000 a year. They are buying a second home—a vacation property—and putting 25% down. Their debt-to-income ratio sits at a comfortable 36%. They apply through a midsize lender for a conventional loan on a site-built home in a suburban neighborhood with plenty of recent comparable sales.

The second is from a household earning $70,000. They are buying their first home, an owner-occupied principal residence, with a 5% down payment. Their debt-to-income ratio is 48%, just below the 50% threshold where denial rates spike. They apply through a high-volume nonbank lender for a Federal Housing Administration (FHA) loan.

Both are real profiles in the public Home Mortgage Disclosure Act (HMDA) data that records mortgage applications, denials and originations. The first household reflects the median applicant of borrowers seeking to buy a second home, whereas the second reflects a typical prospective first-time buyer who was denied a mortgage. One will almost certainly be approved. The other faces long odds. The reasons have less to do with individual effort or financial responsibility than with the structural features of the mortgage market that each borrower must navigate.This post is based on our St. Louis Fed working paper “The Determinants of Mortgage Denial Using Public Data,” April 29, 2026. Also, see “The Determinants of Mortgage Denial,” Federal Reserve Bank of St. Louis Review, Second Quarter 2026, Vol. 108, No. 5, pp. 1-36.

The Paradox: Second Homes Are Easier to Finance Than First Ones

One of the more counterintuitive findings in our data is that loans for owner-occupied principal residences—the most common reason Americans get a mortgage—face higher denial rates than loans on second homes and investment properties.

This is not because lenders apply softer standards to vacation homes or rental properties. If anything, the underwriting criteria for nonprimary residences are stricter: higher minimum credit scores, larger reserve requirements, and no access to FHA or Veteran Affairs (VA) programs. This is a classic case of selection, in which the underlying pool of applicants changes in response to stricter requirements: Only those with a significantly stronger financial profile can meet the higher bars set for second homes and investment properties.

The numbers are stark, as shown in the table below. In 2024, applicants purchasing a second home had a median income of $235,000, more than double the $104,000 median for applicants who plan to reside in the property. Investment property buyers fell between them at $173,000. Debt-to-income ratios tell the same story: a median of 36% for second homes and 37% for investment properties, compared with 41% for owner-occupied purchases. And down payments are larger for second homes and investment properties, each with a loan-to-value ratio of 75%, versus those for owner-occupied houses, with a 91% ratio.

These buyers of nonprimary residences don’t just sit below underwriting thresholds; they sit comfortably far from them. This segment of the market is effectively insulated from the disqualification channel. With debt-to-income ratios averaging 36%—well below the 50% threshold—and substantial 25% down payments, these applications remain mechanically safe even as interest rates rise. That makes their approval almost a mathematical certainty.

Why First-Time Buyers Face a Stacked Deck

Now consider the median first-time buyer as described in the first column of data in the second table. This applicant has a median income and debt-to-income ratio of $104,000 and 41%, respectively. Notice that the owner-occupied applicant is already closer to the institutional thresholds. And the margins are where every feature of the mortgage system compounds against these buyers.

Debt-to-Income Sensitivity

As we documented in the first post of this series, rising interest rates push debt-to-income ratios higher by increasing projected monthly payments. A borrower at a 49% ratio has much smaller buffer than one at 36%. A 2 percentage point rate increase can push the first buyer over the 50% cliff while barely affecting the second.

Loan Type

First-time buyers with limited savings often turn to FHA loans, which allow down payments as low as 3.5%. But FHA loans carry their own friction: mortgage insurance premiums that further increase the monthly payment (and thus the debt-to-income ratio). Buyers of second homes and investment properties, by contrast, use conventional loans almost exclusively and are never in the FHA pipeline.

Lender Composition

Where you apply matters enormously. In our statistical analysis, we considered how similar applicants fared across different lenders. Adding “lender fixed effects” to our regression models causes the explanatory power to jump from 10% (when considering only the borrower’s financials) to over 30%; this means the identity of the lender is highly predictive of the outcome, even after controlling for borrower characteristics. First-time buyers are disproportionately served by high-volume nonbank lenders, which deny at rates of 16% to 20%, nearly double the 9% to 12% rate at midsize lenders. Second-home and investment buyers tend to work with portfolio lenders and midsize institutions where denial rates are lower.

Collateral

A loan-to-value (LTV) ratio of 91% means the lender has thin collateral protection. If the appraisal comes in low—a common risk in markets with volatile prices or limited comparable sales—the deal can fall apart. At an LTV ratio of 75%, the second-home buyer has a 25% equity cushion that absorbs appraisal uncertainty. As we explore in the final post of this series, collateral risk is especially acute for manufactured housing, which is disproportionately purchased by lower-income, first-time buyers.The previous two posts in this series examined the impact of rising mortgage rates on loan denials and the relevance of the 43% debt-to-income threshold in hindering lending.

The challenge for the first-time buyer is not one of these factors alone, but their cumulative impact. When starting with a high debt-to-income ratio and low collateral, the borrower is pushed toward specific loan products and high-volume lenders where the margin for error is razor thin. In this environment, a rise in interest rates does more than increase the cost of debt; it triggers a cascade of institutional barriers that effectively closes the door on homeownership. For this segment of the market, the “stacked deck” means that even small shifts in the macroeconomy can lead to a total loss of credit access.

A System That Rewards Wealth with Access

None of these features of the mortgage market are individually unreasonable. Lenders should care about debt to income, collateral and the ability to repay. Higher down payments should reduce risk. But the cumulative effect is a system in which the borrowers who need credit the most—first-time buyers trying to enter homeownership—face systematically worse odds than those who need it least.

The second-home buyer has a lower debt-to-income ratio, a bigger down payment, a better lender match, and a property that is easier to appraise. Each of these advantages compounds the others. In contrast, the first-time buyer has a higher debt-to-income ratio, a smaller down payment, a lender more likely to deny, and in many affordable markets, a property type that triggers collateral concerns. Each disadvantage compounds the others.

This means that the barriers to credit access are multiplicative, not additive. Policy interventions addressing only one dimension (such as down payment assistance) may produce smaller effects than expected because the other dimensions—like the 50% debt-to-income “cliff”—remain binding.

The Takeaway

The mortgage market treats its most and least constrained applicants very differently. This happens not through any single mechanism but through the accumulation of institutional features that systematically favor borrowers who already have wealth. Understanding this compounding effect is essential for designing policies that expand access to homeownership, rather than addressing one barrier while leaving others intact.

Notes

1. This post is based on our St. Louis Fed working paper “The Determinants of Mortgage Denial Using Public Data,” April 29, 2026. Also, see “The Determinants of Mortgage Denial,” Federal Reserve Bank of St. Louis Review, Second Quarter 2026, Vol. 108, No. 5, pp. 1-36.
2. The previous two posts in this series examined the impact of rising mortgage rates on loan denials and the relevance of the 43% debt-to-income threshold in hindering lending.