Why Your San Antonio Tax Bill Jumped: The 10% Cap, Improvements, and Re-Appraisal

Your homestead exemption is working. The 10% cap is working. Your tax bill still went up 8%, 12%, sometimes more. That is not a BCAD error in most cases — it is how the Texas appraisal cap actually functions, combined with rate-setting by a dozen separate taxing units that BCAD does not control.

The short version: BCAD sets the value, but your city, county, school district, community college district, hospital district, and any MUD or ESD each set their own rate. A flat appraised value with rising rates still produces a bigger bill. And if your appraised value is still climbing toward market value under the 10% cap, the bill climbs even when nothing in your house changed.

Market value vs appraised value: the number that actually gets taxed

BCAD publishes two numbers for your homesteaded property each spring. Market value is what BCAD thinks the house would sell for. Appraised value (also called capped value or assessed value) is the number the taxing units actually use to calculate your bill.

Under Texas Property Code § 23.23, a residence homestead's appraised value cannot increase more than 10% per year, plus the value of any new improvements. The cap kicks in the second January 1 after you qualify for the homestead exemption.

Here is the practical effect. If you bought in 2021 for $300,000 and the San Antonio market ran hard through 2022 and 2023, BCAD's market value may now sit at $410,000 while your appraised value is still catching up at 10% a year. Every year the market value stays above the capped value, your appraised value climbs another 10% — even if market value is flat or dropping. That gap is why people see a tax increase in a year when home prices in their neighborhood actually cooled.

How to read your BCAD notice

Pull your Notice of Appraised Value (it arrives in April) or look it up on BCAD's public property search. Look at three lines:

• Market value — BCAD's estimate of sale price
• Appraised value — the capped number
• Taxable value — appraised value minus your exemptions

If market is well above appraised, you have a gap that will keep pushing your bill up until they meet, regardless of what rates do.

When the 10% cap resets

The cap is not permanent. It resets to market value in a few situations, and this is where owners get blindsided.

• Sale of the property. The new owner starts fresh at market value. A homestead exemption does not transfer with the house; the buyer must file Form 50-114 themselves.
• Loss of homestead status. If you convert the home to a rental or move out and miss the homestead filing on the new primary residence, the cap disappears.
• New improvements. The value of the improvement is added on top of the capped value. The existing structure stays capped; the addition does not.
• A correction of a prior error. If BCAD discovers it missed square footage or a finished basement in prior years, § 25.21 allows back-appraisal.

Under § 25.18, BCAD must reappraise every property at least once every three years. In practice Bexar reappraises annually for most residential parcels, but the three-year rule is why a property that slipped through on low value for a couple of cycles can suddenly jump.

Improvements that trigger re-appraisal — and ones that don't

This is the area that generates the most homeowner surprise. The statute distinguishes between new improvements (taxable as added value) and ordinary maintenance (not added). BCAD field appraisers pull building permits from the City of San Antonio, Bexar County, and suburban cities to flag changes.

Adds value and resets the cap on that portion:

• Room additions, garage conversions to living space, second-story additions
• In-ground pools and spas
• Detached structures with utilities — casitas, ADUs, workshops with electrical
• Finishing out previously unfinished space (bonus room, basement, attic)
• Full kitchen and bath gut remodels that go beyond replacement

Generally does not add value as a new improvement:

• Roof replacement (same materials)
• HVAC replacement
• Water heater, electrical panel, plumbing replacements
• Interior paint, flooring, cabinet refacing
• Fence replacement

The gray area is a renovation permitted as a remodel that BCAD's appraiser interprets as a substantial upgrade. If you pulled a $60,000 permit, expect a call or a field visit. Keep invoices; if BCAD adds $60,000 in improvement value but you spent $45,000 of that on systems replacement (not taxable as new improvement), that is protest material.

The rate side: BCAD doesn't set your bill

A homesteaded property inside San Antonio city limits in NEISD typically pays into:

• Bexar County (general + road and flood + hospital district separately)
• University Health (Bexar County Hospital District)
• Alamo Community College District
• City of San Antonio
• San Antonio River Authority
• Your ISD (NEISD, NISD, SAISD, Alamo Heights, Judson, etc.)

Each sets its own rate every summer through truth-in-taxation hearings. School district rates have actually compressed in recent cycles under state compression rules, but city, county, and hospital district rates can and do move up. A 2-cent increase per $100 on a $350,000 taxable value is $70 — stack that across four taxing units and you are at $280 without any appraised-value change.

The tax bill you receive in October from the Bexar County Tax Assessor-Collector is the sum of all of these. The line items are there; read them.

MUDs and ESDs on the edges

If you bought in a newer master-planned area outside the older city footprint — parts of far west 1604, the 281-north corridor past Bulverde Road, stretches of far south Bexar near Loop 1604 — you may be inside a Municipal Utility District or an Emergency Services District. MUDs issue bonds to fund water, sewer, and drainage infrastructure for new development and levy a separate property tax to service those bonds. A MUD rate of $0.50–$0.85 per $100 on top of everything else is common in the first 10–15 years of a district, then declines as bonds pay down.

ESDs (volunteer fire and EMS in unincorporated Bexar) are smaller — usually $0.08–$0.10 per $100 — but they are another line that can move.

Check your tax bill's taxing-unit list. If a MUD or ESD appears, that is a permanent feature of the property, not a surprise you can protest away.

What most people get wrong

• "The cap means my bill can't go up more than 10%." The cap limits appraised value, not the bill. Rates move independently, and exemptions can change.
• "I protested the market value, so my bill will drop." If your appraised (capped) value is already well below market, lowering market by $20,000 does nothing for this year's bill unless you push market below the capped number. Protest the appraised value that is actually being taxed.
• "My neighbor pays less, so BCAD is wrong on mine." Two identical houses can have legitimately different capped values based on when each owner established homestead and how long the cap has been running. The comparison that matters is equal and uniform appraisal of market value, not final tax bill.
• "I added a pool but didn't pull a permit, so BCAD won't find it." BCAD uses aerial imagery on an annual cycle. Pools, slabs, and new roofs show up. Undisclosed improvements discovered later can be back-appraised under § 25.21.
• "I'll file homestead next year — no rush." Every January 1 you miss with the exemption in place is a year the cap does not run. File Form 50-114 as soon as you close and occupy.
• "My escrow went up so my taxes went up." Not always. Insurance in Texas has climbed hard in recent cycles. Pull the escrow analysis and separate the two lines before you blame BCAD.

What to do this cycle

If your bill jumped, work the problem in order:

1. Open the October tax statement and list every taxing unit and its rate change year-over-year.
2. Pull your April BCAD notice and compare market, appraised, and taxable values to last year.
3. Confirm your homestead exemption is on the account (BCAD public search shows it). If it is not, file Form 50-114 — you can back-file up to two years under § 11.431.
4. If market value looks inflated vs actual neighborhood sales, protest next April. The deadline is May 15 or 30 days after the notice, whichever is later.
5. If you are 65+ or disabled and have not filed for the additional exemption and ceiling, do it now — the school tax ceiling is retroactive to the qualifying year.

If a higher bill is pushing the math on whether to stay, rent out, or sell, browse current San Antonio listings and rentals at RentInSA, compare neighborhoods and their taxing-unit stacks at /resources, or connect with a local agent at /agents who works your ZIP code regularly.