Property Basics
What Is Coinsurance, and How Do You Avoid the Penalty?
Coinsurance is a policy condition that requires you to insure your building for a set share of its value, often 80% or 90%. If your limit is too low, the insurer pays only part of every partial loss, even small ones.
Key Takeaways
- Coinsurance requires your limit to be at least a set percentage (often 80%, 90% or 100%) of the property's value at the time of loss.
- If you carry less, the insurer pays only the share you insured: limit carried ÷ (value × coinsurance %) × loss, minus the deductible.
- The penalty hits partial losses, not just total losses, so a small claim can be cut too.
- Rising construction costs can push a building below its coinsurance requirement without any change on your policy.
- Agreed value, a current valuation and an inflation adjustment are the usual ways owners avoid the penalty.
On This Page
- What Is Coinsurance in a Commercial Property Policy?
- How Is the Coinsurance Penalty Calculated?
- What Does the Penalty Look Like in Real Numbers?
- Why Is Coinsurance a Bigger Risk for Texas Owners Now?
- How Do Agreed Value and Blanket Limits Change Coinsurance?
- How Do You Set a Limit That Holds Up at Claim Time?
- Does Coinsurance Apply to Business Income Coverage Too?
- What Should You Do Next?
What Is Coinsurance in a Commercial Property Policy?
Coinsurance is a condition in most commercial property policies that requires you to carry a limit of insurance equal to at least a stated percentage of the property's value. The percentage, often 80%, 90% or 100%, appears on your declarations page. If you meet it, covered losses are paid in full up to the limit, minus the deductible.
Commercial property coinsurance is not the same as health insurance coinsurance. It is not a percentage of each bill that you always pay. It is a test of whether your limit is high enough. You only feel it when the test fails.
The common standard form, the Building and Personal Property Coverage Form (CP 00 10), includes a coinsurance condition. Texas policies are not standardized, and insurers may use their own approved forms (TDI), so check your own wording.
How Is the Coinsurance Penalty Calculated?
The insurer divides the limit you carried by the limit you should have carried, then pays that share of the loss, minus the deductible. The payment can never be more than your limit.
- Find the value of the property at the time of the loss. On a replacement cost policy, this is usually the cost to rebuild, not the market or purchase price.
- Multiply that value by the coinsurance percentage. This is the minimum limit you needed.
- Divide the limit you carried by that minimum. If the answer is 1 or more, there is no penalty.
- Multiply the loss by that fraction.
- Subtract the deductible. The insurer pays the result, up to the limit.
| Piece | Where to find it | Common mistake |
|---|---|---|
| Value at time of loss | Valuation report or the adjuster's estimate after the loss | Using purchase price, tax value or a years-old figure |
| Coinsurance % | Declarations page, next to each limit | Not noticing it differs by building or coverage |
| Limit carried | Declarations page or statement of values | Assuming the lender's required amount is enough |
| Loss | The covered damage, before the deductible | Forgetting that the penalty applies before the deductible is taken off |
| Deductible | Declarations page and deductible endorsements | Using the wrong deductible for the cause of loss |
What Does the Penalty Look Like in Real Numbers?
The penalty shrinks every partial loss by the same fraction as your shortfall. These simplified examples use round numbers and assume the loss is covered.
Example (Hypothetical): An 80% Clause and a $1,200,000 Limit
A warehouse would cost $2,000,000 to rebuild. The policy has 80% coinsurance, so the owner needs at least $1,600,000. The owner carries $1,200,000. A fire causes $300,000 of damage, and the deductible is $10,000. The fraction is $1,200,000 ÷ $1,600,000 = 0.75. The insurer pays 0.75 × $300,000 = $225,000, minus $10,000 = $215,000. The owner absorbs $85,000: $75,000 from the penalty and $10,000 from the deductible.
Example (Hypothetical): The Same Loss With an Adequate Limit
Same warehouse, same $300,000 fire, but the owner carries $1,600,000. The fraction is 1, so there is no penalty. The insurer pays $300,000 − $10,000 = $290,000. Carrying the right limit added $75,000 to the claim payment.
Example (Hypothetical): A Limit That Was Right Three Years Ago
An office building was valued at $2,000,000 when the owner set an 80% limit of $1,600,000. Three years later, the rebuild cost is $2,500,000, so the minimum is now $2,000,000. The limit never changed. A $400,000 hail and water loss arrives, with a $25,000 deductible. The fraction is $1,600,000 ÷ $2,000,000 = 0.8. The insurer pays 0.8 × $400,000 = $320,000, minus $25,000 = $295,000, instead of $375,000. Nothing on the policy changed. Costs did.
In a total loss, the formula usually pays your full limit (less the deductible), so coinsurance stops mattering. The problem then is plain underinsurance: the limit is lower than the cost to rebuild.
Does the Coinsurance Percentage Make a Difference?
Yes. The same limit can pass an 80% test and fail a 90% or 100% test. The table below uses one building that costs $2,000,000 to rebuild, a $1,600,000 limit and a $100,000 loss before the deductible.
| Coinsurance % | Minimum limit needed | Fraction paid | Paid on a $100,000 loss |
|---|---|---|---|
| 80% | $1,600,000 | 1.00 (no penalty) | $100,000 |
| 90% | $1,800,000 | 0.89 | $88,889 |
| 100% | $2,000,000 | 0.80 | $80,000 |
The value at the time of loss is usually set by the insurer's adjuster from a repair or rebuild estimate. If you disagree with the amount of the loss, many policies include an appraisal clause that lets each side pick an appraiser. Keep your own valuation records so you can support your numbers.
Why Is Coinsurance a Bigger Risk for Texas Owners Now?
Construction costs have risen faster than many building limits. Federal producer price data show prices for inputs to new nonresidential construction rose about 54% from February 2020 to August 2026 (BLS series WPUIP231200 via FRED). That index is national and excludes labor, so it is not your building's cost. It does show why a limit set a few years ago may now be short.
Codes matter too. Texas applies the International Building Code to commercial buildings in cities, and cities may adopt newer editions with local changes (Tex. Local Gov't Code §214.216). Houston, for example, adopted the 2021 International Building Code with local amendments, effective January 1, 2024. Code upgrades are usually handled by ordinance or law coverage, not your base limit, but they add to the real cost of rebuilding.
- Purchase price is not rebuild cost. It includes land, location and income, and it can be far above or below what rebuilding costs.
- Tax appraisals are not rebuild cost. They measure market value for taxes, not construction.
- Old valuations drift. A number from the year you bought the property may now be well below current costs.
How Do Agreed Value and Blanket Limits Change Coinsurance?
Agreed value can suspend the coinsurance condition for a set period, and blanket limits spread one limit across several buildings, usually with a higher coinsurance percentage. Both can help, and both come with conditions.
Agreed value is an optional coverage in the standard form. You and the insurer agree on the values, usually from a signed statement of values, and the coinsurance condition does not apply until the expiration date shown. If you don't renew it with updated values, coinsurance comes back.
A blanket limit covers several buildings or locations with one total limit. Insurers often require 90% or 100% coinsurance on blanket limits, measured against the total of all values. Some blanket policies add a margin clause, which caps what a single building can collect at a percentage of its listed value.
| Approach | How it helps | What to watch |
|---|---|---|
| Accurate building valuation | Removes the shortfall that causes the penalty | Needs updating every year or after major changes |
| Agreed value | Suspends coinsurance until the stated date | Must be renewed with current values |
| Blanket limit | Lets one building borrow limit from others | Higher coinsurance % and possible margin clause |
| Inflation guard | Raises the limit automatically during the year | A fixed % may lag real cost increases |
| Lower coinsurance % | Easier to meet (80% vs. 100%) | Usually costs more per dollar of limit |
Example (Hypothetical): A Blanket Limit With a Margin Clause
An owner has two buildings listed at $4,000,000 and $2,000,000 under a $6,000,000 blanket limit, with a 125% margin clause. Assume the blanket is written on an agreed value basis, so no coinsurance penalty applies. A fire destroys the smaller building, and rebuilding now costs $2,800,000. Without the margin clause, the blanket could pay up to the full loss. With it, that building is capped at 125% × $2,000,000 = $2,500,000, before the deductible. The owner absorbs $300,000. The fix is the same as always: list each building at a current value.
How Do You Set a Limit That Holds Up at Claim Time?
Base the limit on a current estimate of what it would cost to rebuild the building with similar materials, at today's prices. This is your building valuation, and it supports insurance to value: carrying a limit that matches what the property is actually worth to rebuild.
- Use a replacement cost estimate from a valuation tool, appraiser or contractor, not the purchase price.
- Include site features the policy covers, such as canopies, signs, parking lot lighting or fencing, if they are covered under the building limit.
- Update values after renovations, additions or tenant buildouts you own.
- Ask whether your policy offers an inflation guard or agreed value.
- Keep a dated copy of your statement of values and how you arrived at each number.
A Higher Limit Can Raise a Percentage Deductible
If your wind or named storm deductible is a percentage of value, raising the limit raises that deductible too. Recalculate it in dollars. Our deductibles guide shows how.
Does Coinsurance Apply to Business Income Coverage Too?
Often, yes. The standard business income form (CP 00 30) has its own coinsurance condition, measured against your net income and continuing expenses for the 12 months after the policy starts. A business income worksheet helps you estimate that amount.
Some policies replace that test with options such as a maximum period of indemnity, a monthly limit or business income agreed value. Each changes how the limit is measured. Our business income and loss of rents guide walks through the worksheet.
What Should You Do Next?
Check your coinsurance position before a loss, not during one. These steps take about an hour with your policy in front of you.
- Find the coinsurance percentage next to each limit on your declarations page.
- Get a current rebuild cost estimate for each building.
- Multiply each estimate by the coinsurance percentage and compare it to your limit.
- Where the limit is short, ask about raising it, agreed value or an inflation guard.
- Check business income coinsurance with a worksheet.
- Recalculate percentage deductibles at the new limits.
- Put a renewal reminder on your calendar to repeat this each year.
If you'd like help, send us your declarations page and we'll show you where each building stands. Questions are welcome on our contact page.
Questions Owners Ask
Does the coinsurance penalty apply to small claims?
Yes. If your limit is below the requirement, the penalty reduces every partial loss by the same fraction, whether the loss is $20,000 or $2,000,000.
Is coinsurance based on what I paid for the property?
Usually not. On a replacement cost policy, the value is typically the cost to rebuild at the time of loss. On an actual cash value policy, it is that cost minus depreciation. Your policy wording controls.
Can I get rid of coinsurance altogether?
Sometimes. Agreed value suspends it until the date shown on the policy, usually one year, and some policies are written without it, often with other conditions such as a margin clause. Ask what your policy offers.
If my building is a total loss, does coinsurance matter?
Usually not, because the formula pays up to your limit. The real problem in a total loss is that the limit may be lower than the cost to rebuild.
Does the coinsurance percentage change the premium?
Usually. Insurers generally charge less per dollar of limit for higher coinsurance percentages, because they expect owners to insure closer to full value.
Sources
- Texas Department of Insurance — Commercial insurance — Commercial property policies are not standardized in Texas
- Texas Department of Insurance — Commercial property insurance guide
- U.S. Bureau of Labor Statistics via FRED — PPI: Net Inputs to New Nonresidential Construction (WPUIP231200) — Index 109.4 in Feb 2020 vs. 168.275 in Aug 2026
- Texas Local Government Code §214.216 — International Building Code
- City of Houston — Houston Amendments to the 2021 International Building Code — Ord. No. 2023-907, effective January 1, 2024
Next Step
Check this against your policy.
Send your declarations page. We'll show you how your policy handles the points in this guide, in plain English. No obligation.
Or call (713) 367-1706
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