American Miners Act of 2019 This bill transfers certain funds to provide pension and health benefits for retired coal miners who have been affected by issues such as coal company bankruptcies. The Department of the Treasury must transfer additional funds to the 1974 United Mine Workers of America (UMWA) Pension Plan to pay pension benefits required under that plan if the annual limit on transfers under the Surface Mining Control and Reclamation Act of 1977 exceeds the amount required to be transferred for existing obligations of the Abandoned Mine Reclamation Fund. The bill also increases the annual limit on transfers from $490 million to $750 million. The bill also adds miners affected by 2018 coal company bankruptcies to the group whose retiree health benefits are taken into account in determining the amount that Treasury must transfer under current law to the Multiemployer Health Benefit Plan. Additionally, the bill (1) reduces the minimum age for in-service distributions under certain retirement plans, and (2) extends the increased rates for the Black Lung Disability Trust Fund excise tax.