Fixed Rate Mortgages

A fixed rate mortgage is the most common home loan. Your interest rate, and your monthly principal and interest payment, stay the same for the life of the loan. Terms typically range from 10 to 30 years, and in most cases you can pay the loan off early without a penalty. These loans are fully amortized, which means the balance is scheduled to be paid off by the end of the term.
 

If you have an impound (escrow) account, your total monthly payment can still change over time. That’s because your lender may collect extra each month to cover property taxes and homeowners insurance. When taxes or insurance go up or down, the escrow portion of your payment is adjusted. Even so, fixed rate mortgages remain very stable and predictable overall.
 

Adjustable Rate Mortgages (ARMs)

With an adjustable rate mortgage, your interest rate can change over time. ARMs usually start with a fixed rate for an initial period, then adjust based on a market index plus a set margin. Because the starting rate is typically lower than a comparable fixed rate loan, ARMs can help you qualify for a higher-priced home.
 

Most ARMs are amortized over 30 years, with the initial rate fixed for anywhere from 1 month to 10 years. After that, the rate adjusts at set intervals. Each ARM has:
 

• Index – the financial benchmark it follows (for example, 1-Year Treasury, SOFR/LIBOR-type indexes, Prime, or a CD/Cost of Funds index).

• Margin – a fixed percentage added to the index to determine your new rate.
   

When your adjustment date arrives, the lender adds the margin to the current index and usually rounds to the nearest 0.125% to set your new rate. ARMs also have caps that limit how much the rate can move at each adjustment and over the life of the loan.
 

For example, with a 3/1 ARM that has a 2% initial adjustment cap, a 6% lifetime cap, and a starting rate of 6.25%:

• The highest possible rate in year 4 would be 8.25%.

• The highest possible rate over the life of the loan would be 12.25%.

Interest-Only Mortgages

An interest-only mortgage lets you pay only the interest for a set period at the start of the loan. During this time, your required payment does not reduce the principal balance. Interest-only options can be paired with fixed rate or adjustable rate loans.
 

Once the interest-only period ends, the loan becomes fully amortizing. Your payment then jumps because you’re now paying off the full balance over a shorter remaining term. The longer the interest-only period, the larger that new payment will be.
 

You won’t build equity through principal reduction during the interest-only phase, but this structure can:
 

• Lower your initial monthly payment

• Help you qualify for the home you want instead of settling for a smaller one

• Free up cash flow you can invest elsewhere

Example:

• $250,000 loan at 6% on a 30-year fixed:

  • Fully amortizing payment: $1,499/month

• $250,000 loan at 6% on a 30-year term with 5 years interest-only:

  • Years 1–5 (interest-only): $1,250/month

  • Year 6 and beyond (fully amortizing): $1,611/month
     

That’s a savings of $249/month during the first 5 years, but a higher payment later. Many borrowers plan to refinance or sell before the interest-only period ends.
 

Interest-only loans can be useful for borrowers with variable or bonus-based income, especially when the loan allows extra principal payments at any time. In strong income years, you can pay down principal; in leaner periods, you can fall back to the lower interest-only payment.
 

Graduated Payment Mortgages

A graduated payment mortgage starts with a lower payment that increases each year for a set period (for example, 5 or 10 years). After that, the payment becomes fixed for the rest of the term.
 

When rates are high, this structure can make it easier to qualify because your initial payment is smaller. The tradeoff is that in the early years, your payment may not cover all of the interest due. The unpaid interest is added to your loan balance, a situation called negative amortization.
 

Negative amortization happens when:

• The payment for a period is less than the interest charged for that period

• The unpaid interest is added to your principal balance, so the amount you owe actually increases

Graduated payment mortgages can be helpful for borrowers who expect their income to rise steadily over time, but they require careful planning and a clear understanding of how the payment schedule and balance will change.