This study presents an updated interval throwing program (ITP) for baseball pitchers based on biomechanical and workload data. The original ITP, developed over 20 years ago, had a 136-day schedule with a final chronic workload of 15.0 and an acute:chronic workload ratio (ACWR) that exceeded the safe range (0.7–1.3) for 18% of the program. The updated ITP, designed for modern baseball pitchers, has a 217-day schedule with a final chronic workload of 10.8 and an ACWR that exceeded the safe range for only 9% of the program. The updated ITP features a more gradual buildup of chronic workload and a more consistent ACWR, making it safer and more efficient for pitchers returning to competition. The updated ITP incorporates biomechanical data and workload metrics to create a more modern and effective program. It includes a structured progression of throwing distances, intensities, and throw counts, with deload weeks to allow for recovery and maintain a safe ACWR. The program also accounts for the increased velocity and workload of modern pitchers, ensuring a gradual increase in chronic workload to prepare them for competition. The study compares the updated ITP with the original, finding that the updated program has a more gradual chronic workload progression and a more consistent ACWR. This makes it more suitable for modern baseball pitchers and potentially reduces the risk of injury or reinjury. The updated ITP is recommended for use following common injuries or surgeries to the throwing shoulder and elbow, such as Tommy John surgery, and can serve as a basis for future development of shorter duration ITPs. The study highlights the importance of monitoring chronic workload and ACWR in baseball pitching to prevent injury. It also emphasizes the need for a modern ITP that reflects the needs and practices of contemporary baseball players. The updated ITP is designed to be more familiar to modern pitchers and to provide a safer and more efficient return to competition. The program is based on current biomechanical understanding and clinical experience, ensuring a gradual buildup of workload while maintaining a safe ACWR.This study presents an updated interval throwing program (ITP) for baseball pitchers based on biomechanical and workload data. The original ITP, developed over 20 years ago, had a 136-day schedule with a final chronic workload of 15.0 and an acute:chronic workload ratio (ACWR) that exceeded the safe range (0.7–1.3) for 18% of the program. The updated ITP, designed for modern baseball pitchers, has a 217-day schedule with a final chronic workload of 10.8 and an ACWR that exceeded the safe range for only 9% of the program. The updated ITP features a more gradual buildup of chronic workload and a more consistent ACWR, making it safer and more efficient for pitchers returning to competition. The updated ITP incorporates biomechanical data and workload metrics to create a more modern and effective program. It includes a structured progression of throwing distances, intensities, and throw counts, with deload weeks to allow for recovery and maintain a safe ACWR. The program also accounts for the increased velocity and workload of modern pitchers, ensuring a gradual increase in chronic workload to prepare them for competition. The study compares the updated ITP with the original, finding that the updated program has a more gradual chronic workload progression and a more consistent ACWR. This makes it more suitable for modern baseball pitchers and potentially reduces the risk of injury or reinjury. The updated ITP is recommended for use following common injuries or surgeries to the throwing shoulder and elbow, such as Tommy John surgery, and can serve as a basis for future development of shorter duration ITPs. The study highlights the importance of monitoring chronic workload and ACWR in baseball pitching to prevent injury. It also emphasizes the need for a modern ITP that reflects the needs and practices of contemporary baseball players. The updated ITP is designed to be more familiar to modern pitchers and to provide a safer and more efficient return to competition. The program is based on current biomechanical understanding and clinical experience, ensuring a gradual buildup of workload while maintaining a safe ACWR.