Reviewed by AZ Insurance Agency, licensed in Texas, serving Houston since 2003.

Every hurricane season, Houston homeowners start hearing the word TWIA. It shows up in a neighbor's Facebook post, in a real estate listing, in a renewal notice from a carrier. And it produces the same question in thousands of households at once: do I need this, and am I exposed because I do not have it? Since 2003, AZ Insurance Agency has been answering that question for families across Houston and Dallas, and the honest answer surprises most people. For the overwhelming majority of Houston, TWIA is not something you can buy, not something you need, and not a gap in your coverage. Here is exactly how to tell which side of that line your address falls on, and what actually matters instead.

Quick Answer: For most of Houston, no. The Texas Windstorm Insurance Association covers 14 first tier coastal counties plus a small carved out piece of Harris County, and that piece is only five cities: La Porte, Morgan's Point, Pasadena, Seabrook and Shoreacres. Your property has to sit inside those city limits and east of State Highway 146. Both conditions, not either one. Only 4,534 of TWIA's 286,251 policies are anywhere in Harris County, about 1.58 percent of the book. If you live in Katy, Cypress, Sugar Land, The Woodlands or most of the city of Houston, wind and hail are already covered inside your standard homeowners policy.

Key Takeaways

• TWIA is the state created insurer of last resort for wind and hail only, and it is restricted by statute to a defined catastrophe area. It is not a product you can choose to buy because you feel exposed.

• In Harris County, eligibility requires two conditions at once: inside the city limits of La Porte, Morgan's Point, Pasadena, Seabrook or Shoreacres, and east of State Highway 146.

• The shorthand you see almost everywhere, that TWIA covers "Harris County east of Highway 146," drops the city limits condition and gives the wrong answer to a lot of households. Baytown is east of 146 and is not eligible.

• If you are not eligible, wind and hail are already covered inside your standard homeowners policy. Nothing is missing.

• The number inland Houston homeowners should actually check is their wind and hail deductible, which in Texas is often a percentage of dwelling coverage rather than a flat amount.

• Eligible coastal homes usually need three policies working together: homeowners with wind excluded, TWIA for wind and hail, and a separate flood policy.

• TWIA has filed for no rate change four times in a row, yet average premiums have still climbed, because an automatic building coverage endorsement raises your Coverage A about 3 percent at renewal.

In This Guide

• What TWIA actually is

• The five city rule, and how to check your address

• Why so many people get this wrong

• If you are not eligible, what covers your wind

• If you are eligible, the three policy stack

• Why TWIA never covers flood

• Flat rates and rising bills

• The WPI-8 certificate that can stop a policy

• Coverage limits and the increase that was denied

• What is happening with TWIA right now

• Frequently asked questions

What TWIA Actually Is

The Texas Windstorm Insurance Association exists because along parts of the Texas coast, private carriers were unwilling to sell wind and hail coverage at any price a normal household would pay. TWIA is the state created residual market for that risk. It is the insurer of last resort for wind and hail, and only for wind and hail.

Two things follow from that, and both matter.

First, TWIA is geographically restricted by statute. It is not a product you can choose to buy because you feel exposed to storms. Either your property sits inside the designated catastrophe area or it does not, and no amount of wanting the coverage changes that.

Second, inside its own coverage area TWIA is not a fringe option. According to Texas Department of Insurance data for 2024, TWIA holds roughly 53 percent of the residential market within the territory it covers. The market of last resort is the majority market there.

The Five City Rule, and How to Check Your Address

TWIA's designated catastrophe area is the 14 first tier coastal counties, plus a specific piece of Harris County.

That Harris County piece is where nearly all the confusion lives, so here it is exactly as the state defines it. Eligible areas in Harris County are those located east of State Highway 146 and inside the city limits of La Porte, Morgan's Point, Pasadena, Seabrook or Shoreacres.

Both conditions have to be satisfied. Being east of Highway 146 is not enough on its own. Being inside one of those five cities is not enough on its own.

You will sometimes see Shoreacres written as Shore Acres depending on whether you are reading TWIA's materials or the Texas Department of Insurance map. It is the same city.

If your address is close to one of those city boundaries, do not guess from a map app. City limits in that part of Harris County are irregular, and the difference between eligible and not eligible can be one street. That is a five minute check for an agent with the right tools, and it is worth doing before you assume anything about your coverage.

Why So Many People Get This Wrong

The shorthand you will find nearly everywhere, including on plenty of insurance agency websites, is that TWIA covers "the part of Harris County east of Highway 146." That shorthand drops the city limits condition, and dropping it changes the answer for a lot of households.

Baytown is the clearest example. Baytown sits east of Highway 146. Baytown is not on the eligible list. Neither is Clear Lake, Webster, Nassau Bay, or the unincorporated land in between.

The policy counts make the scale of the misconception obvious.

Galveston County alone carries roughly nineteen times the TWIA policy count of all of Harris County. So when a Houston homeowner reads that they "may need TWIA," the statistical reality is that they almost certainly do not.

If You Are Not Eligible, What Covers Your Wind

This is the part that should be reassuring, and it usually gets skipped.

If your home is not in the TWIA area, wind and hail damage is covered inside your standard homeowners policy. It is not missing. It is not a gap. You do not need to add anything, and any agent telling an inland Houston homeowner they are exposed on wind because they lack TWIA is either confused or selling something.

What you should check instead is your windstorm or hail deductible, which in Texas is frequently a percentage of your dwelling coverage rather than a flat dollar amount. Most homeowners have no idea what theirs is set at until they file a claim, and by then the number is fixed.

Estimates only, shown to illustrate how percentage deductibles scale. Your actual deductible is printed on your declarations page.

That deductible number is the single most useful thing for an inland Houston homeowner to know, and it has nothing to do with TWIA. It is the difference between a hail claim being worth filing and not.

If You Are Eligible, the Three Policy Stack

If your home does sit in the eligible area, your coverage does not come from one policy. It typically comes from three, and each one covers something the others exclude.

On the coast, carriers commonly write the homeowners policy without the wind peril, which is why the TWIA piece exists in the first place. Miss one of the three and the gap does not announce itself. It shows up after the storm, when the adjuster explains which policy was supposed to respond and you find out it is one you never bought.

Why TWIA Never Covers Flood

Worth stating plainly, because it is the most expensive misunderstanding on the coast: TWIA covers wind and hail. It does not cover flood. It never has, and it is not designed to.

Your homeowners policy does not cover flood either. Flood is always a separate policy in Texas, in every county, at every price point, from every carrier.

Storm surge is flood. Rising water is flood. Wind driven rain entering through an opening the wind created is a different and more technical question, which is exactly why you want an agent who can read both policies side by side before you file rather than after.

Flat Rates and Rising Bills

Here is something almost nobody explains to TWIA policyholders.

TWIA has now filed for no rate change four times in a row. Zero percent. And yet the average residential premium has moved from roughly $2,000 in mid 2023 to $2,877 as of March 31, 2026.

Flat rates, rising bills. The explanation is an endorsement.

TWIA attaches an automatic building coverage adjustment, form TWIA-220, which increases your Coverage A dwelling amount by about 3 percent at renewal. More coverage costs more premium, so your bill goes up even when the rate did not.

There is a second effect that catches people. If your deductible is expressed as a percentage of Coverage A, raising Coverage A also raises your deductible in real dollars. You are paying more and carrying more risk at the same time, without anyone raising a rate.

The timing detail that matters: this adjustment applies to renewals effective September 1, 2026 and after. If you want to change your Coverage A amount, the request has to reach TWIA before your renewal date. It cannot be backdated afterward. That is a narrow window, and acting inside it is entirely on the policyholder.

The WPI-8 Certificate That Can Stop a Policy

TWIA does not simply insure any structure in the eligible area. Construction, additions and many repairs need a certificate of compliance, commonly called a WPI-8, confirming the work met the applicable windstorm building standards. The certificate is issued through the Texas Department of Insurance.

For the five Harris County cities, the certificate requirement attaches to construction after specific dates in the mid to late 1990s, and those dates differ by city. For work done in certain earlier windows, TWIA may accept a statement from a local building inspector, an engineer or an architect instead.

The practical version: if you are buying a coastal home, or you just had a roof replaced, ask about the certificate before you assume the windstorm coverage will simply continue. Missing documentation on completed work is one of the more frustrating ways a coastal closing gets delayed, and it is almost always discovered late.

Coverage Limits and the Increase That Was Denied

TWIA cannot write unlimited coverage. There are hard ceilings.

TWIA proposed raising the residential maximum. The Texas Department of Insurance disapproved that request in an order dated October 6, 2025. The manufactured home limit did increase.

If your coastal home would cost more than $1,773,000 to rebuild, TWIA alone cannot get you to full replacement value. That is a conversation to have well before hurricane season rather than during it, because the solution involves layering coverage and takes time to arrange.

What Is Happening With TWIA Right Now

Two developments worth knowing as of this month.

The 2027 rate filing. TWIA's board took up the 2027 rate filing on August 4, 2026, in Galveston. Its actuarial committee had already recommended no change by a 4 to 1 vote on June 30. The statutory deadline for the filing is August 15.

Depopulation is effectively dormant. TWIA has a program designed to move policies from TWIA back into the private market. No carrier has participated since 2023. If you are waiting for a private carrier to come take your windstorm risk off TWIA's hands, that is not a plan you can count on right now.

One more thing, because it comes up: the Texas FAIR Plan is a different residual market, and it is much more relevant to inland Harris County than TWIA is. But the FAIR Plan cannot write wind and hail inside TWIA's coverage area. The two do not overlap, and any article suggesting the FAIR Plan is your coastal wind fallback is wrong.

If Spanish Is Your First Language

TWIA does not publish a Spanish language website. Not a partial one, not a translated FAQ. None.

It is worse than that. The Texas Department of Insurance's own Spanish language windstorm page links out to a TWIA Spanish address, and that address resolves to TWIA's English homepage. A Spanish speaking homeowner following the state's own referral lands on a page they cannot read.

If you have been trying to understand your windstorm coverage in Spanish and coming up empty, the material genuinely is not there. That is not on you. Every agent at AZ Insurance can walk you through it in Spanish, including the eligibility check and the deductible on your current policy.

Frequently Asked Questions

Q: Does my Houston home need TWIA windstorm insurance?

Almost certainly not. TWIA covers 14 first tier coastal counties plus a carved out piece of Harris County limited to five cities: La Porte, Morgan's Point, Pasadena, Seabrook and Shoreacres, and only east of State Highway 146. Only about 1.58 percent of TWIA's policies are anywhere in Harris County. If you live in Katy, Cypress, Sugar Land, The Woodlands or most of the city of Houston, wind and hail are already inside your standard homeowners policy.

Q: Is being east of Highway 146 enough to qualify for TWIA in Harris County?

No. That is the single most common error, and it appears on many insurance websites. You need both conditions at once: east of Highway 146 and inside the city limits of one of the five eligible cities. Baytown sits east of 146 and is not eligible. Neither is Clear Lake, Webster, Nassau Bay, or the unincorporated land between them.

Q: If I cannot buy TWIA, am I uncovered for wind damage?

No. If your home is outside the TWIA area, wind and hail damage is covered inside your standard homeowners policy. Nothing is missing and there is no gap to fill. What you should check instead is your wind and hail deductible, which in Texas is often a percentage of your dwelling coverage rather than a flat amount.

Q: Does TWIA cover flood or storm surge?

No. TWIA covers wind and hail only. Flood, including storm surge and rising water, requires a separate policy through the National Flood Insurance Program or a private flood carrier. Your homeowners policy does not cover flood either, in any Texas county.

Q: Why did my TWIA premium go up if TWIA did not raise rates?

TWIA has filed for no rate change four times in a row, but form TWIA-220, an automatic building coverage adjustment, raises your Coverage A dwelling amount by about 3 percent at renewal. More coverage means more premium. If your deductible is a percentage of Coverage A, that deductible also rises in real dollars at the same time.

Q: What is a WPI-8 certificate and do I need one?

A WPI-8 is a certificate of compliance issued through the Texas Department of Insurance confirming that construction, an addition or a repair met the applicable windstorm building standards. TWIA requires it for qualifying work in the eligible area. If you are buying a coastal home or just replaced a roof, confirm the certificate exists before assuming windstorm coverage continues.

Q: How much coverage can TWIA write on a home?

The maximum residential dwelling limit is $1,773,000, and the manufactured home maximum is $119,000. TWIA asked to raise the residential maximum and the Texas Department of Insurance disapproved that request in an order dated October 6, 2025. Homes that cost more than the limit to rebuild need coverage layered on top.

Q: How do I find out for certain whether my address is eligible?

Have an agent check it against the Texas Department of Insurance windstorm map and the city limits, not a general map app. City boundaries in that part of Harris County are irregular and eligibility can change from one street to the next. Call 713-777-2886 and we will confirm your address in about five minutes. Hablamos Español.

Why AZ Insurance Stands Apart

AZ Insurance has protected Texas families since 2003. Real agents in 15 local offices across Houston and Dallas, not call centers reading scripts. Bilingual support so language never gets in the way of understanding your own policy. Over 100,000 customers trust us with their family's protection.

The most useful thing an agent can do with TWIA is tell you when you do not need it. That conversation takes about five minutes and it saves people from buying a policy for a risk their existing coverage already handles. When you bring us a home, we confirm whether the address is genuinely in the eligible area, check the wind and hail deductible on your current policy, tell you whether flood belongs in the picture, and compare 8 carriers on whatever you actually need. If you are one of the households that does need TWIA, we build the full stack so there is no gap between the three policies.

Get a free homeowners quote today from an agent who will tell you what you do not need as readily as what you do.

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