21st Century Assistive Technology Act This bill reauthorizes through FY2026, modifies the funding allocations for, and makes administrative and other changes to programs that increase access to assistive technology devices and assistive technology services for individuals with disabilities. An assistive technology device includes any item, piece of equipment, or system that is used to maintain or improve the functional capabilities of individuals with disabilities (e.g., wheelchairs, hearing aids, or screen readers and computer software), and an assistive technology service is a service that directly assists an individual with a disability with selecting or using such devices, including by evaluating the individual's needs or expanding access to such devices and technology. Specific changes include expanding the scope of certain technical assistance to support grant recipients with data collection, increasing collaboration between agencies that are implementing certain assistive technology grants and state agencies that receive other sources of federal funding for this technology, and adding a more specific focus on older adults in these programs.