30-year fixed, 15-year fixed, and ARM. These are the three options that those looking for a home in Gaithersburg will encounter before consulting a lender. Understanding the numbers first is practically much more helpful, so today I will outline how rates are determined.

The first factor that determines mortgage rates is the yield on the 10-year U.S. Treasury bond. Most 30-year fixed mortgage rates are calculated by adding a spread to this bond yield, so when the bond market moves, mortgage rates follow suit with a lag. The second factor is the Federal Reserve's interest rate policy. While the Fed directly adjusts short-term rates, market expectations about future policy directions are reflected in long-term rates like mortgage rates.

The third factor is inflation. If the inflation rate is higher than expected, bond investors will demand higher yields, which leads to upward pressure on mortgage rates. Additionally, the supply and demand situation in the MBS (Mortgage-Backed Securities) market also plays a role.

As of 2026, based on Freddie Mac PMMS data, the average rate for a 30-year fixed mortgage is found to be in the mid to high 6% range. The 15-year fixed rate tends to be lower, ranging from the high 5% to low 6% range, as shorter repayment periods reduce the lender's risk.

ARM (Adjustable Rate Mortgage) starts with a lower rate than fixed-rate products for the initial 5 or 7 years. After that, the rate adjusts based on a predetermined index, which can be worth considering if long-term residency plans are uncertain, but the risk of rate increases after adjustments must be taken into account.

• 760 and above: Relatively the most favorable rate range
• 680 to 759: Slightly higher rates than average may apply
• Near 620: Possible difference of around 1 percentage point compared to the prime range

In addition to credit scores, the down payment ratio and DTI (debt-to-income ratio) are also assessed, making it difficult to determine results based solely on credit scores. Since there are subtle differences in assessment criteria among lenders, obtaining quotes from multiple places can be practically helpful.

Gaithersburg has many commuting households along the I-270 Tech Corridor, and due to the diverse backgrounds of its residents, the types of properties available are quite broad. With many options ranging from condos to townhouses and single-family homes, it is essential to carefully compare the conditions of different loan products.

If you are a Korean household, it is advisable to obtain a pre-approval letter in advance and organize your income documentation. While there is speculation that future rates may gradually decrease depending on economic indicators, it is still too early to say definitively.