In December 2020 the Horseracing Integrity and Safety Act was passed into law in the United States. This federal legislation superseded most State's Thoroughbred horseracing regulatory oversight. This oversight was implemented through the Horseracing Integrity and Safety Authority (HISA). Partial implementation of HISA began in July 2022. The Horseracing Integrity and Welfare Unit (HIWU) was established to enforce HISA's Anti-Doping and Medication Control (ADMC) Program and full regulatory implementation of HISA began in May 2023. In 2025 following the first three years of HISA and HIWU implementation, health and safety statistics of Thoroughbred racehorses were compared to those prior to HISA's regulatory oversight at Emerald Downs (EMD) a racetrack near Seattle Washington. Following implementation of HISA EMD had significantly more drug testing numbers, with significantly fewer medication violations (adverse findings). Fatal musculoskeletal injuries associated with both racing and training decreased significantly following HISA regulation. Significantly more horses were placed on the veterinarian's list (VL). HISA implementation initiated examination of all claimed horses in Washington State becoming the second largest contributor, after morning examinations, of horses on VL for lameness and unsoundness. Approximately nine percent (9%) of claimed horses having their claims voided due to lameness and unsoundness and placed on the VL. Similar percentages of horses placed on the VL for unsoundness were retired from racing. Concern by stakeholders of undesirable and unanticipated consequences due to bureaucratic complications were realized following implementation of HISA and are described. Overall health and safety statistics improved significantly.