One firm for both halves of accessibility compliance

The firm

ADA Access for All is a New York-based specialized accessibility services firm delivering federally-defensible WCAG conformance testing and regulatory compliance assessments to public-sector and HHS-funded organizations. The firm operates as a DBA of Guillaume & Co. LLC, a New York domestic LLC formed February 27, 2024 (DOS ID 7265133).

It fills a structural gap in accessibility services. Most accessibility firms are either developer-track shops that deliver excellent technical audits but cannot translate findings into the regulatory and procedural artifacts public entities are required to produce, or coordinator-track firms that produce policy artifacts but cannot run a credible federal-standard technical audit. ADA Access for All is built to deliver both — single firm, single accountable principal, single integrated engagement.

The principal

Marc Guillaume founded ADA Access for All to consolidate his combined credentials in federal accessibility testing and ADA Title II coordination into a single specialized practice. His background includes:

• DHS Trusted Tester for Web on Windows (TTv5) — Certificate TT-2604-08987, issued April 22, 2026. The federal Section 508 testing standard cited in Section508.gov procurement guidance.
• ADA Coordinator Certification, University of Missouri — the credential recognized among practicing Title II Coordinators in state and local government.
• Digital Accessibility Certification, Rocky Mountain ADA Center.
• Master of Arts in Urban Policy and Administration.
• Bachelor of Arts in Philosophy and Law, CUNY Brooklyn College.

This combined credential stack — federal-standard technical testing, ADA Coordinator policy work, public-administration education, and regulatory legal training — is unusual in the accessibility services market, and it is the foundation of the firm's hybrid technical and regulatory practice.

Engagement model

ADA Access for All operates as a sole-principal engagement model. The principal performs all testing, authors all deliverables, and signs all attestations. There are no junior staff handoffs and no subcontracted assessment work. The methodology attestation letter delivered with each engagement names the assessor and the credentials under which the assessment was performed.

Standard engagement terms: 50% retainer at signing, balance on delivery, Net-15 payment terms; Confidentiality and Business Associate Agreement execution as required by client status; Professional Liability insurance at $1M per occurrence; engagements priced on a fixed-fee basis from a published rate card.