Rural Microentrepreneur Assistance Act of 2023 This bill reauthorizes through FY2028 and revises the Rural Microentrepreneur Assistance Program (RMAP). This Department of Agriculture program provides loans to eligible microenterprise development organizations to capitalize revolving loan funds that provide loans to qualified rural microenterprises. The bill increases the amount a rural microenterprise may borrow to up to $75,000 (from up to $50,000). The bill also increases the maximum allowable federal cost share to 100% (from 75%). The bill further specifies that a RMAP project loan may not be used to cover more than 50% of any demolition, construction, or related costs of real estate improvements.