Affordable Housing and Area Median Income Fairness Act of 2019 This bill modifies the means by which eligibility for low-income housing assistance and tax credits is determined. The Department of Housing and Urban Development (HUD) is prohibited from considering the New York counties of Westchester and Rockland as within the New York City metropolitan area when determining or establishing area median incomes and income ceilings and limits for the purposes of eligibility for low-income housing assistance. HUD must also assess alternative methods for calculating area median income as well as alternative metrics for use in programs administered by HUD that would make housing more affordable for low-income families in urban areas nationwide. HUD, for the purposes of low-income housing tax credits and exempt facilities bonds, may not apply high housing cost adjustments for any jurisdiction when calculating the area median income or any related metric. A jurisdiction may petition HUD to apply such an adjustment, however. Qualified low-income buildings may not receive a low-income housing credit unless they provide to the relevant housing credit agency certain information required by HUD to determine program compliance. The bill also authorizes through FY2029 certain assistance for jurisdictions for which HUD has applied, or would have applied in the absence of this bill, a high housing cost adjustment.