Texas Counties With the Highest Mortgage Costs — Property Tax Data

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Last verified on: June 21, 2026

Editorial note: This guide is for educational planning only. It compares county-level public data and a simplified mortgage model. It is not a lender quote, tax bill, appraisal, insurance quote, or financial advice.

Research method: This article was manually checked against Tax Foundation 2026 county property-tax data, U.S. Census ACS source notes referenced by that dataset, Texas.gov property-tax transparency guidance, Texas Comptroller property-tax guidance, Consumer Financial Protection Bureau (CFPB) mortgage-cost guidance, and Freddie Mac PMMS rate context on May 21, 2026.

What “Highest Mortgage Cost” Means Here

This article uses a narrow, repeatable definition: principal and interest plus estimated property-tax escrow.

That means the ranking is not a full lender payment quote. It excludes:

• homeowners insurance
• PMI
• homeowners association (HOA) dues
• flood insurance
• MUD or special-district differences inside a county
• closing costs
• lender-specific underwriting adjustments

The goal is to show which Texas counties create the most pressure before those extra costs are added.

Why County Taxes Matter So Much in Texas

Texas has no state property tax. The Texas Comptroller explains that local governments set rates and collect property taxes to fund local services.

Texas.gov gives the practical buyer version: “Multiple taxing units” can tax the same property. That can include a school district, county, city, and special district.

For a buyer with a mortgage, this matters because property taxes are often paid through escrow. The CFPB explains that monthly mortgage costs can include principal, interest, taxes, and insurance. In practice, that means a county’s tax burden can show up as hundreds of dollars per month in the housing payment.

Texas Property Tax by County vs Mortgage Cost

Most county-tax pages answer a narrower question: which Texas counties have the highest property tax rates or tax bills? This article uses that same county-tax foundation, then translates it into mortgage payment pressure.

That distinction matters for buyers. A county with a high effective tax rate may still have a lower monthly escrow cost if median home values are lower. A county with a moderate tax rate can still create a high mortgage payment if home prices are high.

So the buyer-facing question is not only “which Texas county has the highest property tax?” It is “which Texas county creates the highest monthly housing cost after loan amount and tax escrow are combined?”

The Highest-Cost Texas Counties by Median Tax Bill

The table below uses Tax Foundation’s 2026 county property-tax table, which is based on 2024 U.S. Census American Community Survey 5-year estimates. The article’s payment model then converts median annual property tax into monthly escrow and estimates principal and interest at 6.5% on a 30-year fixed loan with 10% down.

The main lesson is that the highest tax bill does not always produce the highest tax rate. Travis County’s effective rate is lower than Fort Bend County’s, but Travis still ranks first by median tax bill because its median home value is much higher.

What This Means for Your Monthly Payment

Property tax turns into monthly payment pressure through escrow.

The formula is simple:

Monthly property tax escrow = annual property tax / 12

For example:

• Travis County median annual tax: $7,727
• estimated monthly tax escrow: $644

If the same buyer estimates only principal and interest, the payment looks incomplete. On a median-value Travis County home in this model:

• median home value: $523,000
• 10% down payment: $52,300
• estimated loan amount: $470,700
• estimated principal and interest at 6.5%: $2,975
• estimated tax escrow: $644
• baseline monthly cost before insurance and PMI: $3,619

That means property tax adds about 22% on top of principal and interest in this simplified example.

Counties Where the Tax Rate Looks Highest

If you sort by effective property tax rate instead of tax bill, the list changes.

This second table is useful, but it can mislead buyers if read alone. A county with a high effective rate but a lower median home value may still produce a smaller monthly tax escrow than a high-value county with a moderate rate.

Why Fort Bend Stands Out

Fort Bend County appears near the top in both views:

• median annual property tax: $6,965
• effective property tax rate: 1.77%
• estimated monthly tax escrow: $580

That combination makes Fort Bend one of the clearest examples of a county where tax rate and tax bill both matter. A buyer comparing Fort Bend with Harris, Dallas, or Bexar should not stop at principal and interest.

How Harris, Dallas, and Bexar Compare

The biggest Texas counties are not all at the top by median tax bill.

These counties still have meaningful monthly tax costs, but the countywide medians are below the highest-cost suburban and high-growth counties in the first table.

For Harris County specifically, the local payment can move higher or lower depending on whether the property is inside Houston city limits, inside a MUD, or subject to other special district lines. That is why a county median should be treated as a starting point, not a property-specific estimate.

Calculator Methodology

The baseline monthly-cost model uses:

• 2024 median owner-occupied home value from the Tax Foundation county table
• 2024 median property taxes paid from the same table
• 90% loan-to-value, meaning 10% down
• 30-year fixed mortgage
• 6.5% annual interest rate, used as a rounded planning rate near mid-May 2026 Freddie Mac PMMS context
• monthly property tax escrow calculated as annual tax divided by 12

The principal-and-interest estimate uses the standard fixed-payment mortgage formula:

Monthly P&I = L * [r(1 + r)^n] / [(1 + r)^n - 1]

Where:

• L is loan amount
• r is monthly interest rate
• n is number of monthly payments

This methodology intentionally excludes insurance and PMI so the property-tax effect is visible. A real lender payment can be higher.

How to Use This Data Before Making an Offer

Use the county table as a first-pass screen, then verify the actual property.

1. Look up the county’s median tax bill to understand the broad market.
2. Open the property-tax statement for the specific home.
3. Check every taxing unit on the statement.
4. Confirm whether a homestead exemption is already applied.
5. Run the number through the Texas Mortgage Calculator.
6. Add insurance, PMI, HOA dues, and any special assessments.

If the property is in Houston or Harris County, use the more specific Houston Mortgage Calculator or Harris County Mortgage Calculator because local tax layers can change the escrow estimate.

Common Mistakes When Comparing Texas Counties

The most common mistake is ranking counties by tax rate only. That misses the effect of home price.

Other mistakes include:

• assuming a county median applies to every neighborhood
• ignoring MUD or special district taxes
• using a seller’s old escrow amount without checking current taxable value
• forgetting homeowners insurance and PMI
• assuming a homestead exemption will transfer automatically
• comparing city rates without school district and county lines

The safer approach is to compare county medians first, then move quickly to the actual tax statement for the home.

Official and Supporting Sources

• Tax Foundation: Property Taxes by State and County, 2026
• U.S. Census Bureau: 2024 ACS 5-year data
• Texas.gov: Property Tax Transparency in Texas
• Texas Comptroller: Property Tax Assistance
• CFPB: What costs come with taking out a mortgage?
• Freddie Mac: Primary Mortgage Market Survey

Next Step

Use the Texas Mortgage Calculator to turn a county-level estimate into a monthly payment scenario. Then verify the home’s actual tax statement before treating the result as affordable.