What Is Section 508?
Section 508 of the Rehabilitation Act of 1973 requires federal agencies to make their electronic and information technology (EIT) accessible to people with disabilities—both employees and members of the public.
In January 2017, the Access Board published a major update (the "508 Refresh") that incorporated the Web Content Accessibility Guidelines (WCAG) 2.0 Level AA into the Section 508 Technical Standards. This means any document—including PDFs—that fails WCAG 2.0 Level AA also fails Section 508.
Key point: Section 508 and WCAG are now effectively the same standard for PDFs. You cannot pass Section 508 without meeting WCAG 2.0 Level AA.
Who Must Comply with Section 508?
Section 508 applies broadly. The key categories are:
Federal agencies
All federal departments and agencies must ensure that all EIT they develop, procure, maintain, or use is accessible. This includes all PDFs on agency websites, intranets, and shared drives.
Federal contractors
Vendors that supply EIT products or services to the federal government must meet Section 508 as a contract requirement. Accessibility must be considered during procurement (FAR Part 39).
Organizations receiving federal funding
Under Section 504 of the Rehabilitation Act, organizations that receive federal financial assistance are required to make their programs and communications accessible—which courts have extended to digital documents.
State agencies with federal programs
When state governments administer federally funded programs, Section 504 and often Section 508 requirements apply to the documents used in those programs.
What Section 508 Requires for PDFs
The Technical Standards reference WCAG 2.0 Level AA Success Criteria. For PDFs, the most important requirements are:
1.1.1 – Non-text Content
All images must have alternative text descriptions. Decorative images must be marked as artifacts so screen readers skip them.
1.3.1 – Info and Relationships
Document structure—headings, lists, tables, form fields—must be marked up with semantic tags so the structure is programmatically determinable.
1.3.2 – Meaningful Sequence
The reading order of content must be logical and follow the visual sequence of the document.
1.4.3 – Contrast (Minimum)
Text must have a contrast ratio of at least 4.5:1 against the background (3:1 for large text of 18pt or 14pt bold).
2.4.2 – Page Titled
The document must have a meaningful title set in its document properties.
3.1.1 – Language of Page
The primary language of the document must be declared in the document properties.
4.1.2 – Name, Role, Value
Form fields and interactive elements must have names (labels), roles, and states that are programmatically exposed to assistive technology.
How to Test a PDF for Section 508 Compliance
Testing requires both automated tools and manual review:
Automated Testing Tools
- Adobe Acrobat Accessibility Checker — built into Acrobat Pro
- PAC (PDF Accessibility Checker) — free tool, tests PDF/UA
- CommonLook PDF Validator — enterprise testing tool used by federal agencies
Manual Testing
- Read the document with NVDA + Chrome or JAWS + Firefox
- Navigate by headings using screen reader heading navigation
- Tab through all form fields without using a mouse
- Check color contrast with a contrast analyzer tool
Important: Automated tools catch only about 30–40% of accessibility issues. Manual testing with a real screen reader is required for a thorough Section 508 evaluation.
Your Section 508 Remediation Options
Fix in the source document
Pros
Best long-term solution. If a Word or InDesign file is the source, fixing it ensures future exports are also accessible.
Cons
Requires training and workflow changes. Only works if the source file is available.
Remediate the PDF directly in Acrobat Pro
Pros
Works without source files. Can fix tags, alt text, reading order, and form fields.
Cons
Time-consuming for non-specialists. Requires understanding of PDF tag structure and WCAG criteria.
Outsource to a PDF accessibility specialist
Pros
Fastest path to compliance. Specialists have the tools and training for efficient, high-quality remediation.
Cons
Cost. For high volume or one-time backlog work, this is typically the most cost-effective option overall.