Why the Same Katy Zip Code Can Owe Two Different Property Tax Bills

A buyer comparing two Katy listings priced five thousand dollars apart pulls up a mortgage calculator and expects two nearly identical monthly payments. Then the lender runs the real numbers using the actual tax rate tied to each address, and the payments land nearly two hundred dollars apart. Nothing about the homes explains the gap. The zip code on both listings might even be the same.

That gap is not a rounding error and it is not random. It is the product of a fact that rarely makes it into a listing description: Katy is not governed by one tax authority. It sits across three counties, and within at least two of its zip codes, the county line runs straight through the middle of the community, splitting otherwise similar homes into different tax worlds.

Katy is not a single tax market. It is three tax markets that share a mailing address.

Three Counties, One Name

Most of what people call "Katy" is actually Harris County on one side, Fort Bend County on another, and Waller County creeping in from the west. Each county runs its own appraisal district, sets its own county-level rate, and processes its own exemptions and protests. Fort Bend County's homeowners average a combined effective rate around 1.65 percent. Harris County tends to run a bit higher once its MUD and special district levies get layered in. Waller County often posts lower base rates, but newer municipal utility districts out that direction can eat into the savings while their bonds are still being paid down.

None of that shows up on a real estate portal's median price banner. It shows up in escrow, on the first tax bill, or in a lender's pre-approval letter when the actual address gets typed in instead of the community name.

The Zip Code That Splits Three Ways

Here is the part that surprises even buyers who know Katy has multiple counties. The same zip code can carry two, sometimes three, different median effective tax rates depending on which county's slice of that zip code a specific parcel sits in.

Look at 77493. A homeowner on the Fort Bend side pays a median effective rate of 1.33 percent. A homeowner in the same zip code on the Harris side pays 2.07 percent, and on the Waller side, 2.37 percent. That is a swing of more than a full percentage point on paper that looks identical until you check which county actually taxes the parcel. The same pattern holds in 77494, where the Fort Bend median effective rate of 1.67 percent sits well below Waller's 2.64 percent for homes carrying the same zip.

For a buyer comparing two similarly priced homes that both say "Katy, TX 77493," this is the number that actually decides the monthly payment, not the square footage or the builder.

Why the MUD Rate Is Doing Most of the Work

Municipal utility districts explain most of that spread. A MUD is a special taxing district formed to finance the water, sewer, drainage, and road infrastructure a new subdivision needs before a city will annex it, and it repays that infrastructure through bonds that homeowners fund over roughly 15 to 25 years. Newer sections carry higher MUD rates because their bonds are freshest. Older sections carry lower rates because the debt is closer to paid off, sometimes retired altogether.

Cinco Ranch is the clearest local example, because it is really two communities wearing one name. The original Cinco I side, built from the early 1990s and centered in the 77450 zip, is a resale-only market at this point, and much of its MUD debt has aged down. The newer Cinco II sections to the west, in the Southwest and Northwest villages that fall largely in 77494, carry younger MUDs with correspondingly higher rates. A buyer who assumes "Cinco Ranch" means one tax profile is working from an outdated picture.

Fort Bend County Municipal Utility District No. 182, which serves the Tamarron community off Tamarron Parkway, is a useful real-world data point. For the 2025 tax year, its board held the rate flat from the prior year at $1.07 per $100 of assessed value, producing only a 0.17 percent increase in taxes for the average homestead. That kind of flat or slowly declining trajectory is normal for a district several years into its bond schedule, though a buyer should always confirm the current rate directly with the district rather than assume it hasn't moved since. Newer districts in communities like Elyson, still in an early construction phase with new-build pricing from the low $230,000s, typically start well above that and work their way down over time.

The Corridor Median Is a Blend, Not a Price

Real estate coverage of Katy tends to quote one corridor-wide median, somewhere in the $340,000 to $398,000 range depending on the month and the data source. That number blends Elyson's entry-level new construction starting near $230,000 with Cinco Ranch's 77450 median running closer to $565,000, and it treats communities with completely different tax profiles as if they were interchangeable.

They are not. Firethorne, for instance, runs roughly 2.58 to 2.86 percent in combined tax rate on homes priced from about $275,000 to $700,000. Cross Creek Ranch spans a similar price band with its own separate MUD structure. Two homes at the same list price in two different Katy communities can carry a meaningfully different total monthly cost once taxes are added to principal and interest, and that difference rarely shows up until an actual offer is being drafted.

Before You Write an Offer

1. Pull the specific address on the appraisal district that matches its county, not just the community name attached to the listing.
2. Ask for a current tax and MUD estimate tied to that exact parcel, not a corridor-wide average.
3. Find out whether the MUD's bonds are early or late in their payoff cycle. Older districts often carry meaningfully lower rates than a neighboring new-build section.
4. File your homestead exemption within the first year of ownership so the school district exemption and the annual appraisal cap start working for you immediately.
5. Mark your county's protest deadline on the calendar rather than assuming it matches a neighbor's in a different county.

Exemptions and Protest Deadlines Worth Knowing

Two changes are worth knowing before closing on a Katy address. The school district homestead exemption increased from $100,000 to $140,000 starting with the 2025 tax year, and it remains the exemption amount Katy homeowners should file for today. Once that exemption is on file, the taxable value on a primary residence cannot rise more than 10 percent in a single year regardless of what the appraised value does.

Protest deadlines are not uniform either, and the difference is worth tracking year over year. In 2026, Fort Bend County and Waller County both set their formal appeal deadline at May 15, while Harris County's window ran to May 21. Both dates have already passed for this tax year, but the gap between them is the point: a household that owns property in a Harris County section and later buys into a Fort Bend section needs to reset its expectations for that date rather than assume it carries over from one county to the next.

FAQ

Does a higher MUD rate mean I should avoid that community? Not by itself. MUD taxes fund the infrastructure that made the subdivision possible in the first place, and rates typically decline over a 15 to 25 year period as the district retires its bonds. A new section quoting a MUD rate above $1.00 per $100 is often just a few years into that schedule, not a sign of a poorly run district.

How do I find the tax rate for one specific Katy address? The community name will not tell you. Look up the parcel directly with the appraisal district for its county, such as the Fort Bend Central Appraisal District, or request a written estimate tied to the exact address before writing an offer.

Why do protest deadlines differ across one metro area? Each county runs its own appraisal district and its own calendar. In 2026, Fort Bend and Waller counties both closed their protest window on May 15, while Harris County's ran to May 21. The exact date can shift slightly year to year, so confirm the current deadline with the appraisal district for the parcel's specific county each spring rather than relying on last year's date.

The corridor median tells you almost nothing about what a specific Katy address will actually cost every month. The county line, the MUD's age, and the exact parcel do. If you are comparing communities and want the real number run against the specific homes you are weighing, JL Fine Homes will pull the tax math for the exact address, not the zip code average. Schedule a consultation and we will walk through it together.