Sewer backups are a nightmare scenario for any homeowner. The sudden influx of raw sewage entering your living space can cause extensive damage, from ruined carpets and furniture to structural issues and health hazards—and have a significant financial impact.
While no one wants to think about this possibility, it's important to understand how your homeowners insurance policy might cover such an event. Keep reading to learn more about home insurance and sewer backups and how you can stay protected and safe.
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At a glance:
A sewer backup occurs when wastewater (sewage and dirty water) flows back up into your home through drains, toilets, and fixtures instead of draining away properly to city treatment plants. This reversal happens when normal drainage paths become blocked or overwhelmed off-premises.
Heavy rainfall can also overwhelm municipal sewer systems, forcing sewage back through residential connections. When storm systems exceed the capacity of aging infrastructure, wastewater has nowhere to go but backward into homes through the lowest available entry points.
The way homeowners dispose of waste also plays a significant role. Cities worldwide have discovered massive "fatbergs"—congealed masses of fats, oils, grease, and non-flushable items like wet wipes and sanitary products; New York City spends nearly $18 million annually clearing sewer blockages caused by improper waste disposal.1 These accumulated materials create blockages in municipal sewer systems, resulting in widespread sewer backups that affect entire neighborhoods.
The age of municipal infrastructure adds to sewer backup problems significantly. In New York, as of 2022, nearly 40% of the state's 35,000 miles of sewers are more than 60 years old and about 10% were built before 1925.2 This means thousands of miles of sewer lines have approached or are exceeding their estimated lifespan, making them more susceptible to breaks, collapses, and blockages that can cause backups into residential properties.
As mentioned, sewer backups can cause significant flooding and contamination, resulting in an unpleasant odor that can not only linger, but also pose serious health risks.
Early detection can enable faster response time and limit damage. Keep an eye out for these common signs of a potential sewer backup can include3:
If you notice any of these signs, it's important to contact a professional plumber immediately to investigate and address the issue.
Typically, homeowners insurance does not cover sewer backup. This exclusion applies regardless of the severity or cause of the backup if it occurred off-premises.
It is important to understand that sewer backup coverage applies to damage caused by the municipal sewage system becoming overwhelmed. Typically, with clogs, tree root penetration of property pipes, aged and disintegrating pipes, etc., the ensuing water damage to the dwelling are covered by the base homeowners policy.
However, depending on your insurance provider and your specific policy, including endorsements (otherwise known as riders), you may have protection against sewer backup for covered perils.
If your home insurance policy includes sewer backup coverage, or you chose to add this coverage to your policy at time of bind, you may have coverage against sewer backup caused by a sudden and accidental discharge from the main sewer line outside your property.4
While a sewer backup endorsement can offer protection when unexpected sewage issues arise, it's important to understand its limitations. Certain circumstances and types of damage are often excluded from this coverage:
Sewer backups are often sudden and dramatic events, but sometimes the intrusion of sewage can be a slow process. In most cases, insurance policies with sewer backup endorsements differentiate between water seepage and sewer backup, and the gradual accumulation of sewage presents a coverage challenge.
The proper functioning of your home's plumbing and sewer system relies on regular upkeep. When problems arise due to inadequate maintenance, insurance providers typically view this as the homeowner's responsibility and outside the scope of a standard sewer backup endorsement.5
While a sewer backup endorsement specifically addresses the overflow of sewage, damage caused by a broader event like a natural flood typically falls under a different type of insurance coverage.
It's important to note that generally, home insurance policies do not cover flood damage, and as such, a flooding endorsement, or separate flood insurance policy, may be required, especially if you live in a region prone to flooding.
It’s important to review your current homeowners insurance policy to determine if your policy includes sewer backup coverage. Many homeowners assume coverage exists when it actually requires separate endorsement purchase. If your base policy does not include coverage, evaluate your property’s risk factors for an informed decision whether or not to add sewer backup coverage:
Discovering sewage backing up into your home can be a distressing and potentially hazardous situation. Follow the steps outlined below to ensure your family stays safe and your home liveable:
When faced with a sewer backup, your well-being should be the top priority. Sewage contains harmful bacteria, viruses, and parasites that pose serious health risks, so it's essential to take immediate steps to protect yourself and your family from exposure by evacuating the affected areas immediately. Shut off electricity to the area if standing water exists.
Contact a licensed plumber immediately for assessment and mitigation. Qualified plumbers have the expertise and equipment to diagnose the cause of the issue and implement the necessary repairs safely and effectively. Avoid DIY repairs during active backups. Professional equipment and expertise ensure a safe and effective resolution.
If you aren’t sure where to start, your insurance agency or independent agent may be able to recommend a trusted vendor who can help.
The smell associated with sewer backups can be incredibly unpleasant and seriously harmful. Improving air circulation in the affected areas is an important step in making the environment safer and more bearable while you address the situation.
Dealing with a sewer backup involves more than just cleanup and repairs; it also requires navigating the home insurance claims process. Having a thorough understanding of the steps involved can help you file a complete and timely claim, increasing the likelihood of a smoother resolution and getting your home back to the way it was, faster.
Moreover, taking proactive steps to prevent backups, from mindful flushing habits to regular plumbing maintenance and considering preventative installations, can significantly reduce your risk.
Ultimately, being informed about your insurance options and implementing preventative measures are your best defenses against the messy and costly reality of a sewer backup, offering greater peace of mind for you and your home.
Sewer backup endorsements provide valuable protection for relatively modest premium increases. The coverage becomes particularly important for homes with basements, older sewer infrastructure, or histories of drainage problems.
Evaluate endorsement limits carefully. Higher-value homes or those with expensive basement finishes may require coverage limits above standard offerings. Understanding sewer backup risks and insurance options enables informed protection decisions. While prevention through proper maintenance and waste disposal remains the most effective strategy, appropriate insurance coverage provides essential financial protection when prevention efforts fail.
Openly offers premium, straightforward home insurance sold exclusively through independent agents. With an enhanced HO-5 base policy and endorsement offerings, Openly provides coverage for mold & fungi, water seepage, and sewer backup.
Visit Openly.com to connect with a local independent agent who can help assess your specific risks and coverage needs.
We provide this information to help you understand insurance. Any coverage is subject to the terms of your policy. Please refer to your policy and declarations page for complete terms, conditions, exclusions and coverage details. Openly may provide links that lead to an external website that may promote goods and services that Openly does not endorse. We are not responsible for the content, claims, or representations made on the linked website. Please review their terms and policies before engaging with any offerings.
1 NYC Environmental Protection. “Fatbergs.” Accessed 29 October 2025. https://www.nyc.gov/site/dep/whats-new/trash-it-dont-flush-it.page
2 American Society of Civil Engineers. “New York civil engineers give the state's infrastructure a "C" grade.” ASCE.org. Published 19 July 2022. Accessed 29 October 2025. https://www.asce.org/publications-and-news/civil-engineering-source/society-news/article/2022/07/19/new-york-civil-engineers-give-the-state-infrastructure-a-c-grade
3 ACME Plumbing Co. “What Are Signs of a Sewage Backup?.” Accessed 21 April 2025. https://www.acmeplumbing.com/what-are-signs-of-a-sewage-backup/
4 Taylor Freitas. “What is sewer backup insurance and how does it work?.” Bankrate. Updated 15 April 2025. Accessed 21 April 2025. https://www.bankrate.com/insurance/homeowners-insurance/sewer-backup-insurance/
5 Sarah Schlichter. “What Is Water Backup Coverage, and Do You Need It?.” Nerdwallet.com. Published 8 October 2024. Accessed 21 April 2025. https://www.nerdwallet.com/article/insurance/water-backup-coverage