Fixed vs. Adjustable Rate Mortgages

The choice between a fixed-rate and adjustable-rate mortgage is one of the most consequential decisions in the homebuying process. The right answer depends on your timeline, risk tolerance, and the current interest rate environment.

Fixed-Rate Mortgages

The rate and monthly payment are locked for the entire loan term (typically 30 or 15 years). Provides complete predictability — your payment in year 30 is identical to year 1 in nominal terms. Best choice for:

• Buyers who plan to stay long-term (7+ years)
• Risk-averse borrowers who value payment certainty
• Periods when rates are relatively low historically
• Borrowers on tight budgets where rate increases would be unmanageable

Adjustable-Rate Mortgages (ARMs)

ARMs start with a fixed period (5, 7, or 10 years), then adjust annually. The rate is tied to a benchmark index (typically SOFR) plus a lender margin. Key caps protect you from extreme increases:

• Initial cap: Maximum increase at first adjustment (typically 2%)
• Periodic cap: Maximum increase at each subsequent adjustment (typically 2%)
• Lifetime cap: Maximum total increase over the loan's life (typically 5–6%)

When an ARM Makes Sense

The typical ARM discount is 0.5%–1.0% below the 30-year fixed rate. On a $400,000 loan, that's $200–$400/month in savings during the fixed period. ARMs make mathematical sense when:

• You plan to sell or refinance before the adjustment period begins
• You expect rates to decline (you can refinance to a lower fixed rate)
• The initial payment savings are significant and you have capacity to absorb future increases
• You're buying in a high-rate environment with expectations of normalization