Mortgage

How mortgages work

The basic mechanic:

1. Buyer makes a down payment (typically 5-20% of purchase price).
2. Lender provides the remaining funds.
3. Buyer signs a note promising to repay, plus a mortgage giving the lender a lien on the property.
4. Buyer makes monthly payments for the loan term, typically 15-30 years.
5. If buyer defaults, lender can foreclose on the property.

The home serves as collateral. Default means losing the home.

Major mortgage types

Several common structures:

• Fixed-rate mortgages — interest rate stays constant. Most common in US.
• Adjustable-rate mortgages (ARMs) — rate changes after an initial fixed period (5/1, 7/1, 10/1 ARMs are common).
• Government-backed mortgages — FHA (3.5% down minimum), VA (0% down for veterans), USDA (rural areas).
• Conventional mortgages — not government-backed; typically requires higher credit scores and 5-20% down.
• Jumbo mortgages — exceed conforming loan limits; specific underwriting standards.
• Reverse mortgages — for borrowers 62+; convert home equity to income.

Monthly payment components

A typical "PITI" payment includes:

• Principal — paying down the loan balance.
• Interest — cost of borrowing.
• Taxes — property taxes, often escrowed by the lender.
• Insurance — homeowner's insurance, often escrowed.

Plus possibly:

• Mortgage insurance (PMI) — required if down payment is below 20% on conventional loans.
• HOA fees — if applicable.

Amortization schedule

Mortgages amortize — fixed monthly payments where the split between principal and interest shifts over time:

• Early in the loan — most of payment goes to interest.
• Later in the loan — most goes to principal.
• By halfway through a 30-year loan — meaningful but not majority of payments are principal.

This is why early extra principal payments save much more than later ones — they eliminate years of interest compounding.

Rate environment and payments

A worked example. $400,000 mortgage:

• At 3% (2020-2021 rates): monthly P&I ≈ $1,686. Total interest over 30 years: $207K.
• At 7% (2024-2025 rates): monthly P&I ≈ $2,661. Total interest: $558K.

The same house costs hundreds of thousands more across the loan's life depending on rate environment.

Down payments and PMI

Standard pattern:

• 20% down — no private mortgage insurance (PMI) on conventional loans.
• 5-19% down — pay PMI until equity reaches 20% of original purchase price.
• 3-5% down — minimum on most conventional and FHA loans.
• 0% down — VA loans for veterans, USDA for rural properties.

PMI typically adds 0.5-1.5% annual cost on the borrowed amount. Avoiding it through 20% down is the traditional advice but often the math favors smaller down payments and investing the difference.

Closing costs

In addition to down payment:

• Origination fees — what the lender charges to process the loan.
• Discount points — pay upfront to lower interest rate.
• Appraisal — cost of professional valuation.
• Title insurance — protects against ownership disputes.
• Recording fees, transfer taxes — government fees.
• Escrow setup — typically 2-3 months of taxes and insurance.

Total closing costs typically run 2-5% of the purchase price.

When to refinance

Several situations favor refinancing:

• Rates have fallen significantly — 0.75-1%+ below current rate justifies most refinances.
• Improved credit allows better rates than original loan.
• Cash-out to access home equity.
• Removing PMI once equity reaches 20%.
• Changing terms — extending or shortening the loan.

Closing costs need to be recovered through monthly savings. The general rule: how many months to break even from monthly savings.

What 2020-2021 vs. 2024-2025 means

The "lock-in effect":

• Borrowers who got mortgages in 2020-2021 at 2-3% rates have enormous savings vs. current rates.
• Selling and re-buying would mean replacing low-rate mortgages with high-rate ones.
• This has reduced housing market mobility — people stay in current homes rather than face higher payments.
• Affects entire housing market dynamics.

The 2020-2021 cohort has effectively been priced into their homes. This dynamic is reshaping housing inventory and pricing in ways that will play out for years.

What individuals should know

For potential homebuyers:

• Lock in rates when conditions are favorable — 30-year fixed mortgages provide predictability.
• Don't stretch beyond comfort. Affordability calculators are aggressive; stress-test against income disruption.
• Watch total cost of ownership. Beyond mortgage payment, taxes, insurance, maintenance, repairs.
• Don't time the market perfectly. Buying when needed often works better than waiting for ideal conditions.

For existing homeowners:

• Refinance opportunities depend on your specific rate vs. market.
• Extra principal payments save substantial interest if you have the cash flow.
• Consider HELOCs for tapping equity if needed.

Mortgages are typically the largest financial commitment most people make. Understanding them well affects long-term financial outcomes more than most other personal-finance decisions.