To encourage greater fixed route transit use for people with disabilities, transit agencies are implementing more rigorous paratransit eligibility determination practices. Previous studies identified best practice strategies for eligibility determination, but did not fully document the implementation of these strategies, nor the factors contributing to successes or challenges. This study interviewed 16 transit agencies across the United States to investigate the use of ADA complementary paratransit eligibility best practices in order to (a) determine the extent to which transit agencies are adopting suggested best practices as part of determining paratransit eligibility, (b) describe how agencies apply these strategies in daily operations, and (c) explore factors that contribute to implementation successes and challenges. Findings indicate that many transit agencies have incorporated multiple best practice eligibility strategies as part of department-wide changes in paratransit operations and have overcome implementation challenges by recognizing departmental limitations and collaborating with other departments and organizations.