The "508 Refresh" is the name given to the Revised 508 Standards, the major 2017 update to Section 508 that the U.S. Access Board finalized with a compliance date in January 2018. Its biggest change was to stop maintaining a separate list of federal technical rules and instead adopt WCAG 2.0 Level A and AA by reference — meaning that for a PDF, conforming to the relevant WCAG 2.0 success criteria is how you conform to Section 508. This post explains what changed, why it still points at WCAG 2.0 rather than 2.1 or 2.2, and what that means for your documents.
For the full picture of who must comply and how PDFs are tested, see the Section 508 PDF compliance guide. This is general information, not legal advice.
A short history: from 1998 to the Refresh
Section 508 was added to the Rehabilitation Act of 1973 by a 1998 amendment. It required federal agencies to make their electronic and information technology accessible — but the original technical standards, issued in 2000, were a standalone set of rules written for the technology of that era. They predated the modern, web-centric way of thinking about accessibility, and over time they drifted out of step with both the web and international practice.
The Access Board began a long rulemaking to modernize them. The result — the Revised 508 Standards, commonly called the 508 Refresh — was finalized in 2017 and became enforceable in January 2018. Rather than reinvent a federal rulebook, the Refresh aligned Section 508 with the standard the rest of the world was already converging on.
| Milestone | Year | What happened |
|---|---|---|
| Section 508 enacted | 1998 | Rehabilitation Act amended to require accessible federal ICT |
| Original 508 standards | 2000 | Standalone, technology-specific technical rules |
| WCAG 2.0 published | 2008 | W3C Recommendation; becomes the global reference point |
| Revised 508 Standards finalized | 2017 | The "508 Refresh" |
| Refresh compliance date | Jan 2018 | WCAG 2.0 A/AA incorporated by reference |
Harmonization with WCAG 2.0 AA and EN 301 549
The defining move of the Refresh was harmonization. Instead of a unique federal checklist, the Revised Standards incorporate WCAG 2.0 Level A and Level AA by reference for web content and electronic documents. The success criteria you'd use to make a web page accessible are the same ones that now govern a federal PDF or Word file.
That choice deliberately aligned the United States with EN 301 549, the European standard for ICT accessibility, which likewise builds on WCAG. The practical benefit is that a document or product built to WCAG can satisfy obligations on both sides of the Atlantic without maintaining two separate definitions of "accessible." It also means the global skills, tools, and documentation built around WCAG apply directly to Section 508 work.
The functional performance criteria
WCAG conformance is necessary, but the Refresh pairs it with something broader: the functional performance criteria (FPC). These are outcome-based requirements describing how a person must be able to use the technology, expressed in terms of ability rather than technique. They cover use:
- without vision and with limited vision
- without perception of color
- without hearing and with limited hearing
- without speech
- with limited manipulation, reach, or strength
- with limited cognition, language, or learning
The FPC act as a backstop and a tie-breaker. If a technical checklist somehow passes but a real person still can't operate the content, the functional criteria are not met — and they also fill gaps where a specific WCAG criterion may not neatly map to a given situation. In other words: passing an automated checker is not the finish line; the document still has to actually work for a human using assistive technology.
What specifically changed for electronic documents and PDFs
For PDFs and other "conventional electronic documents," the Refresh formalized a clear set of expectations by tying them to WCAG. In concrete terms, an accessible federal PDF needs:
- a tagged structure — headings, paragraphs, and lists as real tags, not loose text;
- a logical reading order that matches the visual layout;
- alternative text on meaningful images, with decorative images marked as artifacts;
- a declared document language and a descriptive document title;
- accessible tables with identified header cells; and
- accessible forms with labeled fields and a sensible tab order.
If your documents already meet WCAG 2.0 A/AA at the content level, you are most of the way there. The mechanics of getting tags and order right are covered in the broader Section 508 PDF compliance guide.
Why it still says WCAG 2.0 — not 2.1 or 2.2
A common point of confusion: WCAG has moved on. WCAG 2.1 arrived in 2018 (adding mobile, low-vision, and cognitive criteria), and WCAG 2.2 became a W3C Recommendation in October 2023, adding nine more success criteria. Yet the Revised 508 Standards still reference WCAG 2.0.
The reason is procedural, not philosophical. When the Access Board incorporated WCAG 2.0 "by reference," it pinned the standard to that specific version. Pointing to a newer version requires a formal rulemaking to update the regulation — it doesn't happen automatically when W3C publishes a new edition. WCAG 2.0 was the current Recommendation when the Refresh was written, so that's what got locked in.
| Version | Status | Referenced by Section 508? |
|---|---|---|
| WCAG 2.0 | W3C Rec. (2008) | Yes — incorporated by the Refresh |
| WCAG 2.1 | W3C Rec. (2018) | Not directly; referenced by newer rules (ADA Title II, Section 504) |
| WCAG 2.2 | W3C Rec. (Oct 2023) | No |
| WCAG 3.0 | Early-stage draft | No — not a standard |
How this interacts with newer rules matters in practice. Because WCAG versions are additive and backwards-compatible, building to a newer version generally also satisfies the older one. So a document built to WCAG 2.2 will meet Section 508's 2.0 bar — while also helping with the ADA Title II rule and the Section 504 HHS rule, both of which reference WCAG 2.1 AA. If you operate across more than one of these regimes, the pragmatic move is to target the newest version and let it cover everything beneath it. We explain the newest criteria for documents in WCAG 2.2 explained for PDFs, and contrast the two Rehabilitation Act provisions in Section 508 vs. Section 504.
Key takeaways
- The 508 Refresh (Revised 508 Standards, finalized 2017, effective January 2018) replaced the standalone 2000-era rules.
- It incorporates WCAG 2.0 Level A and AA by reference, harmonizing Section 508 with EN 301 549 and the global WCAG ecosystem.
- It adds functional performance criteria — outcome-based requirements ensuring content actually works for users with different abilities, not just that a checker passes.
- Section 508 still cites WCAG 2.0 because incorporation-by-reference pins a specific version; moving to 2.1/2.2 would require new rulemaking.
- Because WCAG versions are additive, building to WCAG 2.2 satisfies 508's 2.0 bar while also covering the newer ADA Title II and Section 504 requirements that reference 2.1 AA.
