Millennium Challenge Corporation Candidate Country Reform Act This bill modifies the per capita income requirements for countries to be considered candidates for assistance from the Millennium Challenge Corporation (MCC). The MCC program provides assistance to eligible developing countries through a competitive selection process based on various factors, including a country's per capita income, level of economic freedom, and effectiveness of government. Currently, to be a candidate to receive MCC assistance, the country must have a per capita income not greater than the lower-middle-income country threshold established by the International Bank for Reconstruction and Development (IBRD). Under the bill, a candidate country must instead have a per capita income equal to or less than the World Bank's threshold for initiating the IRDB graduation process . (This graduation process begins when IRDB determines that a country is able to sustain long-term development without further IRDB financing. For 2024, the threshold for initiating discussions about a country's graduation begins when a country exceeds $7,805 in per capita income.)