In November 2016, Miller was named national policy director of Trump's transition team.[38] On December 13, 2016, the transition team announced that Miller would serve as Senior Advisor to the President for Policy during the Trump administration.[39] In the early days of the new presidency, Miller worked with Senator Jeff Sessions, President Trump's nominee for Attorney General, and Steve Bannon, Trump's chief strategist, to enact policies restricting immigration and cracking down on sanctuary cities.[40] Miller and Bannon were involved in the formation of the Executive Order 13769, which sought to restrict U.S. travel and immigration by citizens of seven Muslim countries, and suspend the United States Refugee Admissions Program (USRAP) for 120 days, while indefinitely suspending entry of Syrians to the United States.[9][10][11] Miller has been credited as the engineer behind the Trump administration's decision to reduce the number of refugees accepted into the United States.[41]