Md. Code, Tax-Prop. § 9-204

(a) To qualify under this section, a structure shall: (1) have historic value; (2) have architectural value; or (3) be designated under Title 8, § 10–204, or § 22–108 of the Land Use Article, § 10–324 or § 10–325 of the Local Government Article, or the charter powers of Baltimore City, as: (i) an architecturally compatible new structure that is located in a historic district; or (ii) a landmark. (b) A property tax credit of up to 25% of the properly documented expenses of a private owner taxpayer for the restoration and preservation of a structure that the Mayor and City Council of Baltimore City or the governing body of a county or of a municipal corporation determines has historic or architectural value may be granted, by law, by the Mayor and City Council of Baltimore City or the governing body against the county or municipal corporation property tax imposed. (c) A property tax credit of up to 5% of the properly documented expenses of a private owner taxpayer for the construction of an architecturally compatible new structure in a historic district may be granted, by law, by the Mayor and City Council of Baltimore City or the governing body of a county or of a municipal corporation against the county or municipal corporation property tax imposed. (d) If a historic district commission is established by the Mayor and City Council of Baltimore City or the governing body of a county or of a municipal corporation, only the historic district commission shall designate each structure in the county or municipal corporation that is eligible for a property tax credit under this section. (e) A property tax credit granted in 1 year under this section may be applied to any property tax on the structure for up to 5 subsequent tax years. (f) The Mayor and City Council of Baltimore City or the governing body of a county or of a municipal corporation may provide for any procedure or condition necessary to carry out this section. (g) The county or a municipal corporation may require the owner of a structure granted a tax credit under this section to periodically exhibit the structure for public education.