Suicide Prevention Lifeline Improvement Act of 2020 This bill expands the requirements for the National Suicide Prevention Lifeline Program. Specifically, the Substance Abuse and Mental Health Services Administration must (1) develop a plan to ensure the provision of high quality service, (2) strengthen data-sharing agreements to facilitate the transmission of epidemiological data from the program to the Centers for Disease Control and Prevention, and (3) implement a pilot program focused on using other communications platforms (e.g., social media and texting) for suicide prevention. The bill also directs the Government Accountability Office to study the program.