Section 508 vs WCAG 2.1: Which Standard Your Federal Buyers Actually Check
Federal procurement runs on Section 508, which incorporates WCAG 2.0 Level AA. Private litigation cites WCAG 2.1 and 2.2. A store selling to both needs to know which one governs each deal.
A store wins a federal contract and the procurement officer asks for a Section 508 conformance report. The store's accessibility statement says it meets WCAG 2.2 Level AA, and someone in the room assumes that covers it. It does not, quite. Section 508 incorporates WCAG 2.0 Level AA, not 2.1 or 2.2, and the conformance report the buyer wants is a VPAT, not a statement.
The two standards overlap heavily, but they are not the same document, and the difference matters at the point of sale. A vendor who cannot speak to 508 specifically will lose a federal deal to one who can, even if their site is more accessible in practice.
What Section 508 actually requires
Section 508 of the Rehabilitation Act requires federal agencies to make their electronic and information technology accessible. The Access Board's standards, last revised in 2017, incorporate WCAG 2.0 Level AA by reference, along with requirements for software, documentation, and support services that WCAG does not cover. A website that meets WCAG 2.0 AA will usually meet the web parts of 508, but the reverse is not automatic, because 508 also covers things WCAG never touches.
The practical difference between WCAG 2.0 and 2.1 is small but real. WCAG 2.1 added seventeen criteria, including reflow at 320 pixels, non-text contrast, and timeout warnings, and WCAG 2.2 added nine more. A site built to 2.1 AA passes the 508 web requirements and then some, which is why most vendors build to 2.1 and report against 508 separately.
The VPAT, and why buyers ask for it
A Voluntary Product Accessibility Template, a VPAT, is the standard way to report conformance. It lists each criterion, states whether the product supports it, and explains the exceptions. Federal buyers ask for it because it is a comparable document: they can put two vendors' VPATs side by side and see the difference. An accessibility statement is a public promise. A VPAT is a claim about a specific product, and it is the one that gets read in procurement.
The most common VPAT failure is honesty about scope. A VPAT that claims full support for every criterion, with no exceptions and no remarks, is not believed, and experienced buyers treat it as a sign the vendor did not test. A VPAT that lists the known gaps and the dates they will be fixed is more credible, and it is also more useful, because it gives the buyer something to hold the vendor to.
Selling to both worlds
A store that sells to federal buyers and to the public needs two documents and one codebase. Build to WCAG 2.1 Level AA, which satisfies the 508 web requirements with margin, and maintain a VPAT for the federal channel alongside a public accessibility statement for everyone else. Keep the VPAT current after every release, because a VPAT that describes the site as it was six months ago is worse than no VPAT.
The check that matters is the same in both worlds: test with a keyboard and a screen reader, on the flows the buyer will actually use. A federal buyer will test the procurement portal, not the marketing homepage. A private litigant will test the checkout. Both will find the same defects if they exist.
Related reading: Getting a Store Ready for the European Accessibility Act: Dates, Scope, and Evidence, Accessible PDF Invoices, Receipts, and Order Documents for Online Stores, Accessible Loyalty Points and Rewards Dashboards.
Frequently asked questions
What is Section 508?
Section 508 of the Rehabilitation Act requires federal agencies to make electronic and information technology accessible. The Access Board's standards incorporate WCAG 2.0 Level AA by reference, plus requirements for software, documentation, and support services.
Does meeting WCAG 2.2 AA mean I meet Section 508?
For the web parts, usually yes, because WCAG 2.1 and 2.2 include everything in 2.0. But 508 also covers software, documentation, and support services that WCAG does not, and federal buyers want a VPAT reporting against 508 specifically, not a WCAG statement.
What is a VPAT?
A Voluntary Product Accessibility Template is the standard conformance report for Section 508. It lists each criterion, states whether the product supports it, and explains exceptions. Federal buyers use it to compare vendors, and it is the document procurement actually reads.
Should a VPAT claim full support for everything?
No. A VPAT with no exceptions is not believed by experienced buyers. List the known gaps with the dates they will be fixed. An honest VPAT is more credible and more useful than a perfect one.