If you've sat in a meeting where someone said "we have to be 508 compliant" while someone else said "no, it's WCAG" while someone else said "isn't this all the ADA?", this article is for you. The three terms are related but distinct. Knowing which one applies to your agency matters for procurement language, contract requirements, and audit defense.
Section 508
What it is: a section of the Rehabilitation Act of 1973, originally enacted in 1986 and substantially updated in the 2018 "Section 508 Refresh" (36 CFR Part 1194).
Who it applies to: federal agencies and federal contractors, when they procure, develop, maintain, or use information and communication technology (ICT). It does not apply to state or local governments or to private companies that don't sell to the federal government.
What it requires: the 2018 refresh adopted WCAG 2.0 Level A and AA as the technical standard for web content and software. (It is one version behind WCAG 2.1, which means a few criteria that exist in 2.1 are not in 508 — though the gap is small in practice.)
How it's enforced: agencies are required to make 508 compliance representations during procurement; vendors that misrepresent compliance can face contract penalties. Individual employees and members of the public can file complaints under Section 504 (a related provision).
WCAG 2.1
What it is: a technical standard published by the World Wide Web Consortium (W3C) in 2018, formally titled "Web Content Accessibility Guidelines (WCAG) 2.1." It is not a law. It is a specification.
Who must follow it: nobody, by virtue of WCAG itself. WCAG only becomes binding when a law, regulation, or contract adopts it — which many do.
What it contains: 78 success criteria across four principles (Perceivable, Operable, Understandable, Robust) and three conformance levels:
- Level A: 30 criteria. The minimum; failing Level A means assistive tech literally can't access core functionality.
- Level AA: 50 criteria total (Level A + 20 more). The standard adopted by virtually all government accessibility laws worldwide.
- Level AAA: 78 criteria total (everything). Aspirational; not realistically achievable for most content.
Why it matters: WCAG is the actual technical specification that legal standards (508, ADA Title II, EU EN 301 549, Canada's ACA) reference. When someone says "WCAG 2.1 AA," they usually mean the 50 criteria at Levels A and AA combined.
ADA Title II
What it is: Title II of the Americans with Disabilities Act of 1990 (42 U.S.C. § 12131 et seq.) prohibits discrimination on the basis of disability by state and local government entities.
Who it applies to: state governments, local governments (cities, counties, special districts), and public universities. It applies regardless of size, federal funding, or commercial activity.
What it requires for digital content: the DOJ's 2024 final rule (28 CFR Part 35, Subpart H) adopts WCAG 2.1 Level AA as the technical standard for web content and mobile applications. Compliance dates are April 26, 2027 (50,000+ population) and April 26, 2028 (smaller and special districts), after a one-year extension.
How it's enforced: through DOJ enforcement (federal investigation and lawsuits) and through a private right of action in federal court. Individuals can sue without needing DOJ action. In practice, private litigation and demand letters are far more common than DOJ action.
How they overlap
For most public-facing web content created by U.S. state and local agencies, all three standards point to roughly the same place:
| Standard | Applies to | Tech standard | Enforcement |
|---|---|---|---|
| Section 508 | Federal agencies & contractors | WCAG 2.0 AA | Procurement, complaints |
| ADA Title II | State & local government | WCAG 2.1 AA | DOJ + private lawsuits |
| ADA Title III | Private public-accommodation businesses | (no formal rule) | Private lawsuits |
| WCAG 2.1 | (only when adopted by law/contract) | n/a (it is the standard) | n/a |
The California layer
California adds its own statutes that intersect with these federal ones:
- Government Code § 7405: California state agencies and CSU campuses must follow Section 508. Effectively a "use the federal standard" provision.
- Government Code § 11546.7: California state agencies must post accessibility certifications on their websites.
- Unruh Civil Rights Act (Civil Code § 51 et seq.): covers all "business establishments," but California courts have held that public entities can be sued under Unruh for discrimination on the same grounds as ADA Title II. Statutory damages are $4,000 per violation.
For a California city, this means three sources of accessibility obligation overlap: the federal ADA Title II, California Government Code references to Section 508, and Unruh Act exposure. A single inaccessible PDF can theoretically generate exposure under all three.
Which one should I cite in our policies?
For a state or local government agency in the U.S.:
- Cite "WCAG 2.1 Level AA" as the technical standard you adopt.
- Cite "ADA Title II" as the legal authority that requires it.
- Cite "Section 508" only if you contract with the federal government or if your state law (like California's GC 7405) refers to it.
The phrase "WCAG 2.1 AA conformant per ADA Title II" is the cleanest construction for procurement language, accessibility statements, and vendor RFPs.
Practical impact for procurement: when you require vendors to be "WCAG 2.1 AA conformant," ask for a current VPAT 2.4 (Voluntary Product Accessibility Template). The VPAT documents how the product addresses each WCAG criterion. SentraCheck's VPAT is published here.