15-Year Fixed Mortgage Rates in ZIP Code 78666

Today's leading benchmark rate for 15-year fixed rates in 78666, San Marcos, TX is 6.896% (with an estimated monthly payment of $2,287). Calibrated directly to 78666, San Marcos, TX's local housing market, Safe Rate shows up-to-the-minute interest rates and points across Conventional, FHA, VA, and Jumbo loan programs daily.

Mortgage rates for 15-year fixed rates have shown typical daily fluctuations driven by inflation data and bond yields. Over the past 90 days, rates for 15-year fixed rates in 78666, San Marcos, TX have hovered between a low of 6.516% and a high of 6.974%. You can track these daily movements by using the 90-day rate history and trajectory chart featured on this page.

Choosing between FHA and Conventional depends on your down payment budget and credit score. For a typical home priced at $309,122 in 78666, San Marcos, TX, a standard 20%-down Conventional loan requires an upfront cash down payment of $61,824 but keeps your monthly payment lower at $2,287/mo (at 6.896% interest) with no monthly PMI. In comparison, an FHA loan requires only $10,819 (3.5% down) but has an estimated payment of $2,568/mo (at 6.042% interest) due to mandatory FHA mortgage insurance (MIP). Local Nuance: The typical local FHA loan amount of $298,303 falls comfortably within the local HUD FHA loan limit of $524,225 (1-unit), making FHA financing an exceptionally accessible, high-leverage entry point into the market.

The 2025 conforming conventional loan limit for a 1-unit property in 78666 is $806,501. With a typical local home value of $309,122 in San Marcos, a standard 20%-down mortgage requires a loan size of $247,298. Because this is within the $806,501 conforming threshold, buyers can qualify for standard conforming conventional financing with competitive rates.

The median home value in 78666, San Marcos, TX is estimated at $309,122. Buying a typical home here with a standard 20% down payment ($61,824) translates to an estimated starting monthly mortgage payment of $2,287 (principal and interest). Compared to the local area median household income of $56,172 ($4,681/mo), this basic housing payment represents approximately 48.9% of gross monthly household income. Because this housing cost exceeds the standard 36% lender DTI guideline, buyers in this high-value area may need larger down payments, lower debt balances, or co-borrower income to qualify.