Two buyers can put offers on Round Rock homes listed at the exact same price this month and walk away from closing with mortgage payments that differ by hundreds of dollars a month. Same city. Same school district in most cases. Same list price on the settlement statement. The gap shows up on a line most buyers don't think to ask about until it's already sitting in front of them at the title company: the Municipal Utility District tax.
If you've been watching Round Rock listings and comparing them to the median price you saw on a portal search, that number was never going to tell you this. Depending on which source and which few months you're looking at, Round Rock's citywide median has been quoted anywhere from around $370,000 to $420,000 through 2026. Both numbers are true. Neither one tells you what a specific house will actually cost you to own, because Round Rock isn't one housing market wearing one price tag. It's a dozen small ones stitched together under a single city limit sign, and the line that separates them isn't always the one buyers assume.
The Tax Line That Doesn't Show Up in the List Price
A Municipal Utility District, or MUD, is a special taxing entity Texas created to let developers front the cost of water, sewer, and drainage infrastructure in areas that weren't yet served by a city. The MUD board then levies its own annual property tax to pay down that infrastructure debt over time, and that tax shows up as a separate line on your bill alongside city, county, and school district taxes.
In Williamson County, MUD rates run anywhere from about $0.25 to $1.40 per $100 of assessed value, with newer subdivisions typically sitting at the higher end. Layer that onto a base composite rate that already runs somewhere in the 1.7 to 1.9 percent range before any MUD is added, and a property inside an active MUD can push its total effective rate past 2.5 percent. On the ground, that kind of gap can add $300 or more to a monthly payment compared to a similarly priced home just outside the district boundary.
Fern Bluff is a good example of how this plays out inside Round Rock itself. It's an established pocket of 274 homes south of Brightwater Boulevard, and it sits inside its own Fern Bluff Municipal Utility District. A buyer comparing a Fern Bluff listing to a similarly priced home in an older, non-MUD section of Round Rock is comparing two different tax structures wearing the same sticker price.
The fix isn't complicated, but it does require asking the question before you write an offer. Williamson County publishes the actual tax rate worksheets for every MUD in the county, broken out by district and by year. Your agent or lender can pull the exact rate attached to a specific address before you're staring at it on a closing disclosure.
Same School District, Very Different Price Tags
Here's the part that surprises even buyers who've done their homework. It's common to assume that price variation inside a city comes down to school district lines, and in parts of the Austin metro that's true. But within Round Rock proper, that's mostly not what's happening. Leander ISD is a different geography entirely, covering Leander, Cedar Park, and pockets of northwest Austin. If your search is centered on Round Rock, you're almost certainly looking at Round Rock ISD regardless of which subdivision you choose.
So if the school district is holding roughly constant across most of the city, what explains a home in one subdivision running three times the price of a home in another, a few miles away, zoned to the same schools? It comes down to when a neighborhood was built, how big the lots are, and what kind of amenity package the HOA is funding.
Here's what that spread actually looks like across named Round Rock subdivisions, using recent 2026 neighborhood-level pricing:
| Subdivision | Approximate 2026 price level | What sets the price |
|---|---|---|
| Somerset / Old Town Meadows | Low $300,000s | Established, smaller in-city lots, no golf or resort-style amenity package |
| Sam Bass Trails | Low-to-mid $300,000s | Starter-home stock near the Sam Bass corridor |
| Creekbend | High $300,000s to low $400,000s | Newer product mix on mid-size lots |
| Fern Bluff | Mid $400,000s | Established neighborhood inside its own MUD |
| The Woods of Brushy Creek | Mid $400,000s | Larger lots, close to the I-35 commuter corridor |
| Bent Tree | Low $500,000s | Established, larger lot sizes |
| Oak Creek | Low-to-mid $500,000s | Newer builder product |
| Brushy Creek North | Mid $600,000s | Newer construction, larger footprints |
| Brushy Bend Park / Walsh Ranch | High $800,000s to $900,000s | Acreage-style lots, golf-adjacent or custom-build inventory |
That's roughly a three-fold spread, inside one city, largely inside one school district. The citywide median sits somewhere in the middle of that range and describes almost none of the actual homes in it.
Why the Spread Runs This Wide
Part of the answer is simply age. Somerset and Old Town Meadows were built decades ago on tighter, in-city lots, and their prices reflect an established, lower-maintenance product with mature trees and shorter commutes to downtown Round Rock. The Brushy Creek area, by contrast, spans everything from 1980s and 90s-era neighborhoods like Meadows of Brushy Creek to newer, larger-footprint communities, and it's stitched together by the Brushy Creek Regional Trail, which connects Brushy Creek Lake Park and Olson Meadows Park and gives residents direct trail access most older subdivisions don't offer. Cat Hollow, one of the master-planned communities inside that same Brushy Creek footprint, adds a swimming pool, basketball courts, and an 18-hole disc golf course to its HOA amenity list, the kind of package that shows up in resale price even when the school assignment is identical to a neighborhood two miles away without it.
Walsh Ranch and Brushy Bend Park sit at the far end of that curve because their lots are simply bigger, often acreage-style, and their inventory leans toward custom or near-custom construction. None of that shows up in a citywide median. It only shows up when you compare subdivision to subdivision.
The Tax Bill Context Behind This Year's Numbers
Two dated, local decisions are shaping what Round Rock property owners are actually paying right now, and neither is the kind of thing a national housing report picks up.
On July 5, 2025, catastrophic flash floods across Williamson County triggered disaster declarations from the county, state, and federal government, which allowed the county to use an 8 percent revenue growth cap for the year instead of the standard 3.5 percent.
That provision let the county adopt a 2025 rate of $0.413776 per $100, a 3.44 percent increase over the prior year, without triggering a rollback election. It's a specific, traceable reason county tax bills moved the way they did heading into 2026.
Separately, Round Rock's City Council set a maximum tax rate of 42.3 cents per $100 of valuation for fiscal year 2027 on August 13, 2026, up from 37.2 cents the year before. At that rate, the owner of a median taxable-value home of $370,288 pays roughly $131 a month in city taxes alone, according to the city's own budget documentation. The council held its final adoption vote and ratified the rate on September 10, 2026.
None of this is unique to any single subdivision, but it's worth understanding as context for why a tax bill on a home you're evaluating this fall may already look different than what a listing description or an old comp sheet suggests.
There's one more layer of complexity worth knowing before you compare notes with a neighbor. A single Round Rock property can sit inside as many as 19 overlapping taxing districts depending on its exact location, including city, county, school, MUD, and sometimes library or emergency services district levies. Two homes a few streets apart can have genuinely different composite rates for reasons that have nothing to do with the home itself.
A Framework That Actually Holds Up
If you're comparing Round Rock listings this fall, the citywide median is a starting point for a search bar, not a planning number. A framework that holds up looks more like this. Confirm whether the specific address sits inside a MUD, and if so, pull the current rate from the county's own worksheet rather than relying on an old listing sheet. Verify the exact school assignment directly with Round Rock ISD rather than assuming it from the zip code, since boundaries do shift. Compare price per square foot within the subdivision you're actually considering, not against the city as a whole. And if a MUD is involved, ask how far along the district is in paying down its infrastructure bonds. Rates in mature MUDs run lower than in brand-new ones, because the debt that funded the original water and sewer buildout gets retired over 20 to 30 years.
Round Rock ISD's own tax rate, at $0.8931 per $100, is actually the lowest among the county's largest school districts. It still accounts for roughly 53 percent of a typical homeowner's total bill, simply because the school district is the largest single line item on almost every property tax statement in the county, regardless of which subdivision that statement belongs to.
Frequently Asked Questions
Does every subdivision in Round Rock have a MUD? No. Older, more established neighborhoods like Somerset and Old Town Meadows generally don't carry one, while several newer or infrastructure-heavy subdivisions, including Fern Bluff, do. It has to be confirmed address by address.
Is Round Rock ISD the only school district serving the city? For the vast majority of Round Rock addresses, yes. Leander ISD covers a separate geography centered on Leander and Cedar Park. Always confirm the exact zoned campuses directly with the district before making an offer, since attendance boundaries can shift.
Do MUD taxes ever go away? They decrease over time as the district's infrastructure bonds are paid down, typically over 20 to 30 years, though the rate and timeline vary by district.
If you're trying to figure out what a specific Round Rock subdivision actually costs to own, not just to buy, that's exactly the kind of comparison worth doing before you write an offer. LaTashia Mitchell can walk through the tax worksheet, the school assignment, and the real total payment for any Round Rock address you're considering. Let's Connect.
