What Is a Mortgage?
A mortgage is a loan used to purchase or refinance real estate, where the property itself serves as collateral. This means the lender holds a legal claim — called a lien — on the home until the borrower repays the debt in full. If the borrower stops making payments, the lender can pursue foreclosure, a legal process that allows the lender to take ownership of the property to recover the unpaid balance.
Most US mortgages are structured as amortizing loans, meaning each monthly payment covers both interest and a portion of the original loan amount (the principal). In the early years of repayment, a larger share of each payment goes toward interest; over time, more of it reduces principal. This structure is why paying even slightly more than the minimum each month can meaningfully shorten the life of the loan.
Amortization Works in the Lender's Favor Early On
In the first years of a 30-year mortgage, the vast majority of each payment covers interest rather than principal. Even making one extra principal payment per year can meaningfully reduce total interest paid and shorten the loan term. Ask your servicer to apply any extra payment specifically to principal.
For a detailed walkthrough of what happens between loan approval and the transfer of keys, see our guide to the full home purchase lifecycle.
Types of Mortgages Available
US borrowers can choose from several mortgage structures. Understanding each helps you match a loan to your financial situation.
- Conventional loans are not insured by a government agency. They typically require stronger credit and a down payment of at least 3–20%. Loans that meet Fannie Mae and Freddie Mac guidelines are called conforming loans.
- FHA loans are insured by the Federal Housing Administration and allow down payments as low as 3.5%, making them accessible to buyers with modest credit histories.
- VA loans are guaranteed by the Department of Veterans Affairs and are available to eligible service members, veterans, and surviving spouses — often with no down payment required.
- USDA loans are backed by the US Department of Agriculture for qualifying buyers in eligible rural and suburban areas.
- Fixed-rate mortgages lock your interest rate for the entire loan term — commonly 15 or 30 years — providing predictable payments.
- Adjustable-rate mortgages (ARMs) start with a fixed rate for an initial period, then reset periodically based on a benchmark index. They carry more payment uncertainty over time.
ARM Rate Resets Can Increase Your Payment Significantly
Adjustable-rate mortgages can offer lower initial rates, but once the fixed period ends, your rate — and monthly payment — can rise substantially depending on benchmark index movements. Before choosing an ARM, understand the rate caps (periodic and lifetime) and model what your payment would look like at the maximum allowed rate.
How Lenders Evaluate Borrowers
Lenders use a set of financial metrics — often called the Four Cs — to assess how likely a borrower is to repay the loan.
- Credit
- Your credit score (commonly a FICO score) is one of the first things a lender reviews. Scores generally range from 300 to 850; most conventional lenders look for 620 or higher, though FHA programs accept lower scores. Your full credit and banking profile — including payment history and existing debt — also matters.
- Capacity
- Lenders calculate your debt-to-income ratio (DTI) — your monthly debt obligations divided by your gross monthly income. Most lenders prefer a back-end DTI (all debts) below 43%, though some programs allow higher ratios with compensating factors.
- Capital
- Down payment funds, cash reserves, and other assets demonstrate financial stability and reduce lender risk.
- Collateral
- The home must appraise at or above the purchase price; the lender needs assurance that the property is worth the loan amount.
~65%
US homeownership rate
The US Census Bureau consistently reports that roughly 65% of American households own their homes, the majority with a mortgage.
43%
Common maximum DTI threshold
The Consumer Financial Protection Bureau (CFPB) identified 43% back-end DTI as the general qualified mortgage ceiling, though many lenders apply different standards.
2–5%
Typical closing cost range
Industry estimates consistently place closing costs between 2% and 5% of the loan amount, varying by location, loan size, and lender.
If you want to strengthen your position before applying, our article on preparing financially for a mortgage covers exactly what to review.
The Mortgage Application Process
Applying for a mortgage follows a structured sequence of steps.
- Pre-approval: A lender reviews your income, assets, and credit to issue a conditional commitment for a loan amount. This is distinct from pre-qualification, which is a less rigorous estimate.
- Home search and offer: With a pre-approval letter, you can make competitive offers. Once a seller accepts, you enter a purchase contract.
- Loan application and processing: You formally apply, providing documentation such as tax returns, pay stubs, bank statements, and employment verification. A processor compiles your file for underwriting.
- Underwriting: An underwriter evaluates your complete file, orders an appraisal, and either approves, suspends, or denies the loan.
- Closing disclosure review: At least three business days before closing, you receive a Closing Disclosure detailing final loan terms and costs.
Request Loan Estimates from at least three lenders on the same day so you're comparing identical market conditions. Even a 0.25% rate difference on a 30-year loan can translate to tens of thousands of dollars in total interest.
Rate shopping is the single highest-leverage action a borrower can take; studies from the CFPB indicate many borrowers compare only one lender and forgo significant savings.
Before closing, ask your lender specifically whether your loan is likely to be sold to a different servicer — and keep a paper record of your first several payments until any transfer is confirmed.
Loan transfers are common in the US secondary mortgage market; confusion during handoffs can occasionally lead to misapplied payments or escrow errors that are difficult to untangle retroactively.
The Consumer Financial Protection Bureau (CFPB) requires lenders to issue a Loan Estimate within three business days of application — review it carefully to compare competing offers on equal terms.
Understanding Mortgage Costs
The purchase price is only part of what you pay. Borrowers should budget for several additional costs:
- Down payment: Typically 3–20% of the home's purchase price, depending on the loan type.
- Closing costs: These generally run 2–5% of the loan amount and include origination fees, title insurance, appraisal fees, prepaid property taxes, and homeowners insurance escrow.
- Private mortgage insurance (PMI): Required on conventional loans with less than 20% down. PMI protects the lender — not the borrower — and is typically canceled once the borrower reaches 20% equity.
- Annual percentage rate (APR): The APR expresses the true yearly cost of a loan, incorporating interest plus certain fees. Comparing APRs across lenders is more informative than comparing interest rates alone.
- Points: Borrowers can pay discount points upfront — each point equals 1% of the loan amount — to reduce the ongoing interest rate. Whether this makes financial sense depends on how long you plan to keep the loan.
Review Your Loan Estimate and Closing Disclosure Carefully
Federal law requires lenders to provide a Loan Estimate within three business days of application and a Closing Disclosure at least three business days before closing. Compare these documents line by line. If fees increase beyond allowed tolerances, the lender may be required to cover the difference. Never sign closing documents without understanding every line item.
From Closing to Payoff
Once the loan closes and you take ownership of the property, the mortgage enters its repayment phase. Several important concepts apply during this stage.
Loan Servicers
The company that manages your monthly payments — collecting funds, handling escrow, and fielding questions — is your loan servicer. This may be the original lender or a separate company the loan was sold to on the secondary market. You must be notified in writing if your loan is transferred to a new servicer.
Escrow Accounts
Most servicers maintain an escrow account funded by a portion of each monthly payment. This account pays your property taxes and homeowners insurance on your behalf, preventing large lump-sum bills.
Refinancing
Refinancing replaces your existing mortgage with a new one — often to secure a lower interest rate, change the loan term, or access home equity. Refinancing involves a new application, appraisal, and closing costs, so it only makes financial sense if the long-term savings outweigh those upfront expenses. For broader guidance on the home buying and selling process, our topic hub covers each stage in depth.
Payoff
A mortgage is paid off either at the end of the scheduled term or when the borrower sells the home, refinances, or makes a lump-sum payoff. A payoff statement from your servicer shows the exact amount needed to satisfy the debt on a specific date.
This article is for general informational and educational purposes only and does not constitute personalized financial, legal, or mortgage advice. Mortgage products, rates, requirements, and regulations vary. Consult a licensed mortgage professional or financial adviser for guidance tailored to your individual circumstances.
