In the United States, accessibility standards for websites come down to one technical benchmark, the Web Content Accessibility Guidelines (WCAG), applied through several different laws depending on who you are. State and local governments have a binding rule that names WCAG 2.1 Level AA, with compliance dates of April 26, 2027 for larger governments and April 26, 2028 for smaller ones and special districts. Federal agencies and their contractors follow the Section 508 Standards, which incorporate WCAG 2.0 Level AA. Organizations funded by the Department of Health and Human Services must meet WCAG 2.1 Level AA by May 11, 2027 or May 10, 2028, depending on size. Airlines have had a WCAG 2.0 AA requirement for their websites for years. And private businesses, the largest group by far, have no written technical rule at all under the ADA, yet courts, plaintiffs and settlements measure them against WCAG anyway. The practical answer for almost every US website in 2026 is the same: build and test to WCAG 2.1 Level AA, and treat WCAG 2.2 AA as the better target where you can reach it.
That convergence is the part people miss when they first go looking for "the" accessibility standard. They expect one law with one checklist, and instead they find a federal statute from 1990 that never mentions websites, a handful of agency rules with different versions of WCAG, a set of state laws with their own penalties, and a guideline written by a standards body rather than a government. We spend our days scanning sites against these standards, and the same confusion shows up again and again: an agency is sure its client is fine because "the ADA has no website rule," or a buyer assumes a vendor's badge means the law is satisfied. Both are wrong in ways that cost money. On our own benchmark of 57 web agency front pages, every single site had at least one accessibility finding against these standards, including the sites of the people who build websites for a living. This article maps the whole picture: what the standards are, which one applies to whom, what they actually ask your pages to do, and how to check your own site honestly.
What are accessibility standards?
An accessibility standard is a published, testable set of requirements that describes what a website, app or document must do so that people with disabilities can perceive it, operate it and understand it. The key word is testable. A law can say "do not discriminate against people with disabilities," but it takes a standard to turn that into something a developer can build and an auditor can check: text alternatives for images, enough contrast between text and background, every function operable from a keyboard, forms that tell people what went wrong.
In the US, two kinds of documents get called "accessibility standards," and it helps to keep them apart. The first kind are technical standards, which describe the requirements themselves. For the web, that is WCAG almost without exception. The second kind are legal instruments, the laws and regulations that decide who has to meet a technical standard and by when: the ADA, Section 508, Section 504, the Air Carrier Access Act, and a growing number of state laws. The legal instruments rarely write their own technical rules for websites. Instead, they point at a version and level of WCAG and say "this one." Once you see that pattern, the whole picture gets much simpler. The question stops being "which of twenty standards applies to me" and becomes "which law covers me, and which version of WCAG does it point at."
There is a third category worth naming so it does not confuse anyone: the 2010 ADA Standards for Accessible Design. Those are real, binding accessibility standards, but they cover buildings and facilities (ramps, door widths, restroom clearances), not websites. If a search result says "ADA standards" and starts talking about parking spaces, it is the physical standard, not the digital one.
Is WCAG the official US accessibility standard?
WCAG is not a US law, but it is the technical standard that every US digital accessibility rule relies on. It is published by the World Wide Web Consortium (W3C), an international standards body, and it is organized around four principles: content must be perceivable, operable, understandable and robust. Under those principles sit testable success criteria, each assigned a level. Level A is the minimum, Level AA is the level laws and settlements reference, and Level AAA is the highest and is rarely required for whole sites.
The version matters, because different US rules point at different versions. WCAG 2.0 was published in 2008 and is still the version named by Section 508 and the airline rule. WCAG 2.1, published in 2018, added success criteria aimed largely at mobile use, low vision and cognitive disabilities, and it is the version named by the 2024 ADA Title II rule and the 2024 HHS Section 504 rule. WCAG 2.2, which the W3C published as a Recommendation in October 2023, added further criteria (larger default target sizes for clickable controls, focus that is not hidden behind sticky headers, accessible authentication that does not depend on memory puzzles) and removed one obsolete criterion. The versions are designed to be backward compatible in practice: a page that meets WCAG 2.2 AA also meets 2.1 AA and 2.0 AA, which is why building to the newest version you can manage is the safest way to satisfy every rule that names an older one. According to the W3C's WCAG overview, the guidelines are meant to be technology-neutral, so they apply to websites, web apps, documents and mobile content alike.
You may also see WCAG 3 mentioned. It is a working draft with a different structure and scoring model, it is years from being finished, and no US rule references it. It is worth watching, not worth building to.
Which accessibility standard applies to your website?
This is the question that decides everything else, so here it is by type of organization. Most organizations fit one category; some fit two, and when that happens you meet the stricter one.
Private businesses: ADA Title III
Title III of the Americans with Disabilities Act covers "public accommodations," which in practice means most businesses that serve the public: retailers, restaurants, hotels, banks, healthcare providers, professional services and e-commerce. Title III has no regulation setting a technical standard for websites. As the American Bar Association's Business Law Today explains, the Department of Justice has not issued a technical accessibility standard for public accommodations' websites through regulation, and its 2022 web guidance pointed to WCAG and the Section 508 Standards as helpful references without making either mandatory.
That gap does not mean there is no standard in practice. It means the standard is set by courts, settlements and demand letters rather than by a regulation, and all three use WCAG, overwhelmingly WCAG 2.1 AA. The volume is not small. According to UsableNet's ADA web lawsuit trends report, more than 5,000 digital accessibility lawsuits were filed in 2025 across federal and key state courts, with e-commerce absorbing the large majority. If you want the wider numbers on how common the underlying failures are, our web accessibility statistics for 2026 walks through them. The honest reading for a private business is that "there is no written rule" is technically true and practically irrelevant: the measuring stick everyone will use is WCAG 2.1 AA.
State and local governments: ADA Title II
Title II covers state and local governments and everything they run: cities, counties, courts, public schools and universities, transit authorities and special districts. In April 2024 the DOJ published the first binding web rule under the ADA, adopting WCAG 2.1 Level AA as the technical standard for web content and mobile apps. The original compliance dates were April 24, 2026 for larger governments and April 26, 2027 for smaller ones.
Those dates moved. As the University of Arizona's accessibility office summarized, the DOJ published an Interim Final Rule on April 20, 2026 that pushed the date for public entities with a population of 50,000 or more from April 24, 2026 to April 26, 2027, while leaving WCAG 2.1 AA in place as the standard. Smaller entities and special district governments moved to April 26, 2028. The law firm Duane Morris noted that the extension changes only timing and does not suspend Title II's underlying nondiscrimination and effective communication obligations, which have supported web accessibility claims for years without any technical rule. We covered exactly what changed, and what did not, in our explainer on the ADA Title II deadline moving to 2027.
Federal agencies and their contractors: Section 508
Section 508 of the Rehabilitation Act requires federal agencies to make the information and communication technology they develop, procure, maintain or use accessible. The current Section 508 Standards, revised by the U.S. Access Board in 2017 and in effect since January 2018, incorporate WCAG 2.0 Level A and AA by reference. The scoping rule for electronic content, E205.4, says it plainly: electronic content shall conform to Level A and Level AA success criteria in WCAG 2.0, as a Federal Depository Library Program training deck on the Revised 508 Standards lays out.
Section 508 applies directly to federal agencies, not to private websites. Its reach extends further than that sounds, though, because agencies write the standard into their contracts. A software company, agency or vendor selling to the federal government is usually asked to show conformance, typically through an Accessibility Conformance Report built on the VPAT template. And many state governments copy Section 508 into their own procurement rules.
Healthcare and HHS-funded organizations: Section 504
Section 504 of the same Act prohibits disability discrimination by recipients of federal financial assistance. In May 2024 the Department of Health and Human Services finalized a rule that adopts WCAG 2.1 Level AA for the web content and mobile apps of organizations it funds: hospitals and health systems taking Medicare or Medicaid, community health centers, Head Start programs, and many others.
That rule's dates moved too. According to HHS's Interim Final Rule on public inspection at the Federal Register, the compliance date for recipients with fifteen or more employees was extended from May 11, 2026 to May 11, 2027, and the date for recipients with fewer than fifteen employees from May 10, 2027 to May 10, 2028. The technical standard stays WCAG 2.1 AA, and the rule continues to cover content provided through contractors and third-party arrangements, which matters for every patient portal, scheduling widget and telehealth front end built by a vendor.
Airlines: the Air Carrier Access Act
Airlines are the quiet precedent that most people outside aviation have never heard of. Under the Department of Transportation's rule at 14 CFR 382.43, the primary websites of US and foreign carriers selling to US customers must conform to WCAG 2.0 Level AA, and the deadline for all public-facing pages passed in December 2016. DOT has enforced it. In 2018 it fined Scandinavian Airlines $200,000 after the carrier built a separate "assistive" website instead of making its primary site conform. According to the DOT order, SAS violated the rule when it created a separate site for individuals with disabilities rather than ensuring its primary site met WCAG 2.0 AA. That case is a useful lesson well beyond airlines: a parallel "accessible version" is not a substitute for an accessible primary site.
State laws: California, Colorado and beyond
States add their own layer, and two deserve attention. California's Unruh Civil Rights Act makes any violation of the ADA a violation of state law and attaches statutory damages. A Santa Barbara Superior Court ruling restates the rule: a defendant is liable for actual damages, up to three times actual damages, but in no case less than $4,000 for each instance of discrimination. That minimum is why so much website litigation is filed in California.
Colorado went further for its public sector. HB21-1110 makes inaccessible government technology a state civil rights violation, and the state Office of Information Technology adopted WCAG 2.1 AA as the standard. According to the Colorado Municipal League, entities that miss the standard can face a court order, damages, or a $3,500 fine per plaintiff, and a grace-period defense for good-faith efforts ran only until July 2025. Other states are following with procurement rules and education-sector requirements. If you operate in several states, the safe assumption is that the strictest one sets your floor.
Why is WCAG 2.1 AA the practical target for almost everyone?
Look across every category above and the pattern is hard to miss. The two newest federal rules, ADA Title II and HHS Section 504, both name WCAG 2.1 AA. Colorado names WCAG 2.1 AA. Courts and settlements under Title III overwhelmingly use WCAG 2.1 AA. The older rules, Section 508 and the airline rule, name WCAG 2.0 AA, which is a strict subset of 2.1 AA. So a site that conforms to WCAG 2.1 AA satisfies the technical standard of every US rule currently in force.
That is why our default advice is simple: build and test to WCAG 2.1 AA as the minimum. If you are designing something new, aim for WCAG 2.2 AA. It costs little extra at design time, it covers a few real usability gaps (tiny tap targets and focus hidden under sticky headers are among the most common complaints from keyboard and touch users), and it future-proofs you against the next rule update, which is very likely to name 2.2. What you should not do is target Level A alone. Several of the failures that generate the most complaints, color contrast among them, are Level AA requirements.
What do accessibility standards actually require your pages to do?
The full WCAG 2.1 AA set is 50 success criteria, and reading them cold is not how most teams should start. In practice the same handful of failures account for most of what we find on real sites, and fixing them gets you a long way. The most common is low text contrast: WCAG AA requires a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text, and light grey text on white fails it on a huge share of sites. On our agency benchmark, 45 of 57 front pages had at least one contrast failure. If that is your starting point, our step-by-step guide on how to fix low color contrast covers the exact ratios and how to fix them at the design-token level so your brand survives.
Behind contrast, the recurring failures are images with no text alternative, form fields with no programmatic label, links and buttons with no accessible name (an icon with nothing behind it reads as "button" to a screen reader), page structure that skips heading levels or puts content outside any landmark, and functions that cannot be reached or operated from a keyboard. Each of those maps to a specific criterion, and each is usually cheap to fix in the source, especially when the problem lives in a shared component and one fix propagates everywhere. A lot of today's new failures come from exactly there, which we unpack in our piece on how small code quality issues quietly break accessibility.
The criteria that take more thought are the ones about behavior rather than markup: whether focus moves in a logical order, whether a modal traps keyboard users, whether errors are explained in words and not only in red, whether content still works when zoomed to 200 percent, whether video has captions. For a plain-language pass through all of them in the order a team should tackle them, our ADA website compliance checklist is built for exactly that.
Does meeting an accessibility standard make you compliant?
Meeting the standard is the technical half of compliance, and it is the half you can measure. But it helps to be precise about what "meeting" means, because this is where many teams fool themselves. WCAG conformance is defined criterion by criterion. A page conforms to Level AA only if it satisfies every applicable Level A and AA criterion, and the W3C is explicit in WCAG 2.1's conformance section that conformance is assessed against the full set, with no partial credit. One unmet criterion means the page does not conform, no matter how good the rest is.
That has a direct consequence for tooling. Automated testing catches a real but limited share of WCAG failures, the ones a machine can decide by reading the page. It cannot judge whether alt text says anything meaningful, whether focus order makes sense, or whether a screen reader user can complete your checkout. A green score from an automated tool tells you the machine-checkable criteria passed. It does not tell you the page conforms, which is the whole argument of our piece on why a Lighthouse score of 100 is not WCAG compliance. Real conformance work combines an automated pass across every page with manual testing of the flows that matter: keyboard only, then a screen reader, then zoom.
And conformance is not the same thing as legal safety. The laws above are about whether people with disabilities can actually use your service. A site that conforms on the day of an audit can stop conforming the next week when a new component ships. None of this is legal advice, and your specific obligations depend on your sector, your state and your customers, which is a conversation for a qualified attorney. What we can say from experience is that the organizations that hold up are the ones that treat the standard as a continuing practice rather than a one-time certificate.
Do accessibility overlays meet accessibility standards?
No. An overlay is a JavaScript widget that tries to patch accessibility in the visitor's browser at runtime, on top of the existing code. WCAG conformance is a property of the content itself, so a widget that leaves the underlying markup unlabeled, unstructured and low-contrast does not make that content conform. The airline case above is a cousin of the same idea: a separate accessible layer is not a substitute for an accessible primary site.
The enforcement record points the same way. In 2025 the Federal Trade Commission required a leading overlay vendor to pay $1 million, as TechCrunch reported, over claims that its widget could make any website WCAG compliant, and a meaningful share of businesses sued for inaccessibility already had a widget installed. We gathered that evidence in our analysis of whether accessibility overlays protect you from lawsuits, and we lay out our own position, and why we fix issues at the source instead, on our page explaining why fixing the source beats an overlay. The short version: the standard measures your code, so the fix has to live in your code.
How do I check my website against accessibility standards?
Start by deciding which rule covers you, using the categories above, and write down the target: almost always WCAG 2.1 AA, with 2.2 AA as the stretch. Then work through it in the order that produces honest evidence rather than reassurance.
First, run an automated scan across your real pages, not just the homepage, so the machine-detectable failures are listed with their locations and the criteria they map to. This is the fastest way to clear the high-volume problems, and it is the part you can repeat every week. You can run a free scan of up to five pages, no signup, which maps each finding to the WCAG criterion it fails and labels how certain the finding is, so you know which items are confirmed and which need a human to look.
Second, test the flows that matter most by hand. Put the mouse away and complete your sign-up, checkout, search and contact form using only the keyboard. Then do the same with a screen reader. Zoom the browser to 200 percent and see what breaks. These checks find the criteria no scanner can judge.
Third, fix at the source, in templates and shared components, so a single change clears every instance. Prioritize what blocks a task outright and what repeats across every page.
Fourth, document what you found and fixed, and publish an honest accessibility statement that names your target standard, your method and your known limitations. Our free accessibility statement generator assembles the W3C structure from those inputs, in your browser, without storing anything. Then repeat the scan on a schedule, because the standard applies to the site you have next month, not only the one you audited.
Frequently asked questions
What are the accessibility standards for websites in the US?
The technical standard is WCAG, applied through several laws. ADA Title II and HHS Section 504 require WCAG 2.1 Level AA. Section 508 and the airline rule require WCAG 2.0 Level AA. ADA Title III has no written web rule, but courts and settlements use WCAG 2.1 AA as the benchmark.
Is WCAG 2.1 AA legally required for private businesses?
No federal regulation names it for private businesses. In practice, though, WCAG 2.1 AA is the measure plaintiffs, courts and settlements use under ADA Title III and state laws like California's Unruh Act, so it is the standard a private business should build to.
What is the difference between WCAG 2.0, 2.1 and 2.2?
Each version adds success criteria on top of the last. 2.1 added criteria for mobile, low vision and cognitive needs. 2.2 added more, such as minimum target sizes and focus that is not obscured. A page meeting 2.2 AA also meets 2.1 AA and 2.0 AA.
When do government websites have to meet WCAG 2.1 AA?
Under the DOJ's April 2026 Interim Final Rule, state and local governments with 50,000 or more people must comply by April 26, 2027. Smaller governments and special districts must comply by April 26, 2028. Existing ADA obligations apply in the meantime.
Does Section 508 apply to my company?
Section 508 applies directly to federal agencies. It reaches private companies when they sell technology to the federal government, because agencies require conformance in contracts, usually documented in an Accessibility Conformance Report. Some states also copy Section 508 into their procurement rules.
Are the ADA Standards for Accessible Design about websites?
No. The 2010 ADA Standards for Accessible Design cover physical buildings and facilities. Website requirements come from WCAG, through the ADA Title II rule, Section 508, Section 504 and court practice under Title III.
Can an accessibility overlay make my site meet WCAG?
No. WCAG conformance is a property of your content and code. A runtime widget that leaves the underlying markup broken does not make it conform, and regulators have penalized vendors for claiming otherwise.
How often should I check my site against accessibility standards?
Continuously. Run an automated scan on a schedule so regressions surface quickly, and retest key flows by hand after any material change. A site that conformed at its last audit can fail the next time a component ships.
The bottom line
The US does not have one accessibility standard for websites. It has one technical benchmark, WCAG, and a set of laws that point at it: WCAG 2.1 AA for state and local governments (now due April 2027 or April 2028), WCAG 2.1 AA for HHS-funded organizations (May 2027 or May 2028), WCAG 2.0 AA for federal agencies under Section 508 and for airlines under the ACAA, and WCAG 2.1 AA as the de facto measure for private businesses under ADA Title III and state laws with real damages behind them. That convergence is good news, because it means a single target covers almost everyone. Build to WCAG 2.1 AA, aim for 2.2 AA when you can, fix failures in the source rather than layering a widget on top, test the parts a machine cannot judge, and keep checking after launch. If you want to see where your own site stands against that target today, start with a scan, read what it finds, and let that be the first page of your evidence.
Sources
W3C WAI, WCAG Standards and Guidelines Overview
W3C, Web Content Accessibility Guidelines (WCAG) 2.1, Conformance
American Bar Association, Digital Accessibility Under Title III of the ADA
Duane Morris, DOJ Extends ADA Title II Digital Accessibility Deadlines by One Year
Federal Register (public inspection), HHS Section 504 Interim Final Rule Extending Compliance Dates
Federal Depository Library Program, Section 508 and WCAG
U.S. Department of Transportation, Scandinavian Airline System Order 2018-11-8
Superior Court of California, County of Santa Barbara, Tentative Ruling 25CV07064
Colorado Municipal League, Digital Accessibility
UsableNet, ADA Web Lawsuit Trends for 2026: What 2025 Filings Reveal
TechCrunch, FTC orders AI accessibility startup accessiBe to pay $1M for misleading advertising
This article is educational and reflects Sitejar's point of view. It is not legal advice. For your specific situation, consult a qualified attorney.