United States 5G Leadership Act of 2019 This bill establishes U.S. policy for the commercial deployment and security of fifth generation (5G) networks and the development of the U.S. information and communications technology industry. Specifically, the bill prohibits the use of funds from a universal service support program to buy equipment or services from providers that pose a national security risk (i.e., Huawei Technologies Co. Ltd., Zhongxing Telecommunications Equipment Corporation, or their subsidiaries or affiliates). The bill establishes the Supply Chain Security Trust Fund, from which the Federal Communications Commission must make grants to U.S. communications providers to replace equipment from such entities. Additionally, the bill requires the National Telecommunications and Information Administration to report on steps the federal government is taking to secure deployment and availability of 5G networks, and it requires the Department of Homeland Security to establish an interagency program to share information regarding security, risks, and vulnerabilities with U.S. communications providers. Lastly, the bill prioritizes the use of federal funds to enhance U.S. representation at international 5G standard-setting forums.