A buyer closes on a new construction home in Katy this fall. The builder's sales office quoted a monthly payment based on a partial-year tax bill, the kind that only accounts for a few months of assessed value because the house wasn't finished on January 1. The number looked manageable. Then the following January arrives, the Fort Bend or Harris County appraisal district reassesses the property at full completion value, and the real bill lands. Depending on the community, that jump can run 40 to 60 percent higher than what the buyer budgeted for in year one.
This isn't a rare hiccup. It's baked into how Texas assesses new construction, and it's one of the most common surprises buyers report after closing on homes in Katy's fast-growing subdivisions. If you're comparing a new build in Elyson or Sunterra against a resale in an older section of Cinco Ranch, the sticker price tells you almost nothing about what you'll actually owe once the second bill arrives.
The Bill That Arrives a Year Late
Here's the mechanic behind it. When a home is under construction, the appraisal district can only tax the value of the property as it existed on January 1 of that tax year, which might be raw land or a partially built structure. The builder or the buyer pays a small partial bill that first year. Once the home is complete and the next January 1 rolls around, the appraisal district reassesses at full market value. That's when the real tax obligation kicks in, and it's disconnected from whatever number appeared on the builder's closing disclosure or the online mortgage calculator a buyer used to shop.
Pair that with a new Municipal Utility District tax, and the gap widens further. A MUD is a special-purpose local government that Texas allows developers to create so they can bond out the cost of water, sewer, and drainage infrastructure before a single house is sold. Homeowners in the district repay those bonds through an added tax rate, typically half a percentage point to a full percentage point on top of the base county and school rate. It's not a separate line item you can spot and question. It's folded directly into the property tax rate, so it's invisible until you look up the specific address.
Katy Is Actually Three Tax Systems Wearing One Zip Code
Here's where Katy gets more complicated than most Houston suburbs. The city technically stretches across Harris, Fort Bend, and Waller counties, and which county your specific lot sits in determines your appraisal district, your baseline county rate, and where you file your homestead exemption and protest paperwork. Two homes a few streets apart in different sections of the same master-planned community can fall under different appraisal districts entirely.
The pattern that's held for years still holds now: development pushing further west toward Brookshire tends to land in Waller County, where county-level rates generally run lower, though newer MUDs out that direction can offset some of that advantage with fresh bond debt. Fort Bend County covers the bulk of Katy's established master-planned footprint, including sections of Cinco Ranch and Firethorne. Harris County picks up the neighborhoods closer to I-10 and the older city core.
None of this shows up when you filter listings by price on a portal. It only shows up when someone pulls the actual account and traces which taxing entities have jurisdiction over that address.
What the MUD Rate Is Actually Paying For, and Why It Falls Over Time
The tax rate in a given MUD isn't arbitrary. It tracks how much bond debt the district is still carrying and how far along it is in paying that debt off. A newer section still building out its second or third phase is often still servicing recent bond issuances, which keeps the rate elevated. A mature section that's been collecting taxes for fifteen or twenty years has usually paid down a meaningful chunk of that debt, and the rate drifts lower as a result, even though the home's market value keeps climbing.
That's the mechanism behind a pattern you'll see across the Fort Bend County tax rolls covering Katy: subdivisions in the newest phases of communities can carry combined rates in the 3.2 to 3.6 percent range, while sections of older, more established neighborhoods such as Kelliwood or Nottingham Country tend to sit closer to 2.2 to 2.8 percent. The rate isn't a judgment on the neighborhood. It's a snapshot of how much infrastructure debt is still outstanding and how long ago that debt was issued.
Here's the range in practical terms:
| Community stage | Example | Typical combined effective rate |
|---|---|---|
| Newer phases, active bond debt | Firethorne, newer sections of Tamarron | ~3.2% to 3.6% |
| Established, largely paid-down debt | Kelliwood, Nottingham Country | ~2.2% to 2.8% |
Same List Price, Very Different Monthly Payment
Run the math on a $500,000 home. A quarter-point difference in effective tax rate between two otherwise identical properties works out to $1,250 a year, or roughly $104 a month. Stretch that gap to a full percentage point, which is realistic when comparing a newly bonded MUD against a mature one, and you're looking at $5,000 a year, or over $400 a month, added to the payment before insurance is even factored in. That's enough to change what a lender qualifies a buyer for, and enough to make two homes at the same list price feel entirely different once escrow is calculated.
This is why the median price you see on a portal search is a starting point at best. If you're comparing new construction in Elyson, Sunterra, or Grange against a resale in an established section of Cinco Ranch, the honest comparison isn't the list price. It's the full combined tax rate on the specific address, pulled from the appraisal district, not estimated from a citywide average.
Katy's citywide numbers themselves illustrate why averages mislead. As of August 2026, one major portal reported a median list price near $399,000 with homes spending a median of 72 days on market, while other trackers using slightly different windows through the spring and early summer reported medians ranging from roughly $350,000 to $363,000 with days on market anywhere from 24 to 45. Those aren't contradictions so much as evidence that Katy isn't one market. It's dozens of small ones, each shaped by its own tax district, inventory pace, and bond schedule, all rolled into a single headline number that doesn't describe any specific street.
The Two Dates Worth Marking Every Year
Earlier this year, Texas raised the school district homestead exemption to $140,000, a substantial jump that reduces the taxable value used to calculate your school tax bill, which is usually the largest single line on a Katy tax statement. That filing window runs on the same clock every year: Form 50-114 goes to whichever appraisal district covers the property, Fort Bend Central Appraisal District, Harris Central Appraisal District, or Waller County Appraisal District, and closes April 30. If you closed on a Katy home earlier in 2026 and haven't confirmed the exemption is on file, it's worth a call to the appraisal district before next spring's cycle opens.
The other recurring date is the protest deadline. Fort Bend Central Appraisal District sets it at May 15 each year, or 30 days after your Notice of Appraised Value is mailed, whichever is later. According to the district's own appeals process, most disputes are resolved at the informal conference stage, before a formal hearing is ever needed. A senior reporter covering Katy for the Houston Chronicle spoke with FBCAD's Deputy Chief Appraiser about the mistakes that sink most protests, and the pattern was consistent: owners who show up with comparable sales and clear documentation settle quickly, while owners who expect an automatic reduction without evidence tend to walk away disappointed.
If you're closing on new construction anytime this year, the calendar to watch isn't the day you close. It's the following January 1, when the appraisal district reassesses at full value, and the spring after that, when the exemption and protest windows open.
A Few Questions Worth Answering Directly
Does a lower MUD rate mean a better neighborhood? No. It usually means the community has been collecting taxes longer and has paid down more of its original infrastructure debt. A newer community with a higher rate may have better current amenities precisely because that debt funded them.
Can city annexation eliminate a MUD tax? Not automatically. Annexation changes who provides certain services, but existing bond obligations to the MUD generally continue until they're retired or restructured through a separate agreement.
Should I ask for a tax estimate before I write an offer? Yes, on any Katy property, new or resale. The seller's most recent tax bill and the appraisal district's account lookup will show you the actual combined rate for that specific address, not a citywide estimate.
Comparing homes across Katy's subdivisions means comparing tax districts as much as square footage. Pamela Kinney brings a rare combination to that comparison: broker experience across Katy's neighborhoods and licensure as a property tax consultant, which means the tax math isn't an afterthought, it's part of how she helps clients evaluate a property before they write an offer. If you're weighing new construction against an established Katy neighborhood, The Real Estate Agency of Houston can walk through the actual numbers with you. Let's Connect.
