Magento storefront accessibility support limits with themes and extensions

Improving accessibility in the user-facing workflow requires a clear understanding of where Magento provides documented support and where compliance becomes implementation dependent.

Core UI components are built using ARIA roles and keyboard operable patterns intended to support WCAG 2.1 AA level conformance for Adobe Commerce. Page Builder and UI Component rendering output markup is accessible by default in core. Core checkout, minicart and navigation include focus management and keyboard navigation behaviors.

Accessibility is not enforced for custom widgets, theme overrides, or third-party modules. Those behaviors can be altered or broken when templates or JavaScript are overridden by extensions or custom themes. Claims about WCAG conformance refer to core features only and do not guarantee compliance for a merchant customized instance.

There is no documented automated accessibility validation gate in Magento Marketplace technical review, and the decision of whether to require accessibility testing or block non-compliant extensions remains unresolved in public documentation.

What documented limits apply to accessibility guarantees when core templates are overridden by a theme or extension? Is there a documented policy for Marketplace technical review regarding accessibility testing requirements for extensions? Does Magento document how merchants should verify WCAG 2.1 AA support for a customized storefront given the current enforcement gap?