EXHIBIT 21

AMERICAN COMMUNITY PROPERTIES TRUST
CONSOLIDATED ENTITES AND SUBSIDIARIES OF THE REGISTRANT
DECEMBER 31, 1999

At December 31, 1999, the financial statements of the following entities were consolidated with those of the Registrant in the Consolidated Financial Statements incorporated herein:

• American Community Properties Trust, a Maryland business trust
• American Housing Management Company, a Delaware corporation
• American Housing Properties L.P., a Delaware limited partnership
• American Land Development U.S., Inc., a Maryland corporation
• American Rental Management Company, a Delaware corporation
• American Rental Properties Trust, a Maryland real estate investment trust
• Fox Chase Apartments General Partnership, a Maryland general partnership
• Headen House Associates Limited Partnership, a Maryland limited partnership
• IGP Group Corp., a Puerto Rico corporation
• Interstate General Properties Limited Partnership S.E., a Maryland limited partnership
• Lancaster Apartments Limited Partnership, a Maryland limited partnership
• LDA Group, a Delaware limited liability company
• Land Development Associates S.E., a Puerto Rico partnership
• New Forest Apartments General Partnership, a Maryland general partnership
• Palmer Apartments Associates Limited Partnership, a Maryland limited partnership
• St. Charles Community, LLC, a Delaware limited liability company
• Wakefield Terrace Associates Limited Partnership, a Maryland limited partnership
• Wakefield Third Age Associates Limited Partnership, a Maryland limited partnership

At December 31, 1999, the Registrant and its consolidated entities had the following significant unconsolidated subsidiaries:

• Alturas del Senorial Associates Limited Partnership, a Maryland limited partnership
• Bannister Associates Limited Partnership, a Maryland limited partnership
• Bayamon Gardens Associates Limited Partnership, a Maryland limited partnership
• Brookside Gardens Limited Partnership, a Maryland limited partnership
• Carolina Associates Limited Partnership, a Maryland limited partnership
• Colinas de San Juan Associates Limited Partnership, a Maryland limited partnership
• Crossland Associates Limited Partnership, a Maryland limited partnership
• ELI GP, Inc., a Puerto Rico corporation
• ELI S.E., a Puerto Rico special partnership
• Escorial Builders S.E., a Puerto Rico special partnership
• Essex Apartments Associates, a Virginia limited partnership
• Huntington Associates Limited Partnership, a Maryland limited partnership
• Jardines de Camparra Associates Limited Partnership, a Maryland limited partnership
• Lakeside Apartments Limited Partnership, a Maryland limited partnership
• Maryland Cable Limited Partnership, a Maryland limited partnership
• Monserrate Associates Limited Partnership, a Maryland limited partnership
• Monte de Oro Associates, a Maryland limited partnership
• New Center Associates Limited Partnership, a Maryland limited partnership
• San Anton Associates, a Massachusetts limited partnership
• Turabo Limited Dividend Partnership, a Massachusetts limited partnership
• Valle del Sol Limited Partnership, a Maryland limited partnership