Difficult Development Areas

Difficult Development Areas This U.S. Department of Housing and Urban Development feature layer depicts Difficult Development Areas in the United States. Per HUD, “Difficult Development Areas (DDA) for the Low Income Housing Tax Credit program are designated by U.S. Department of Housing and Urban Development (HUD) and defined in statute as areas with high construction, land, and utility costs relative to its Area Median Gross Income (AMGI). DDAs in metropolitan areas are designated along Census ZIP Code Tabulation Area (ZCTA) boundaries. DDAs in non-metropolitan areas are designated along county boundaries. DDAs may not contain more than 20% of the aggregate population of metropolitan and non-metropolitan areas, which are designated separately." Baltimore/Columbia/Towson Small Area DDA Data currency: Current Federal Service (Difficult Development Areas 2025) Data modification: None For more information: Housing and Urban Development; Difficult Development Area Tables For feedback, please contact: [e-mail] Department of Housing and Urban Development Per HUD, “The Department of Housing and Urban Development administers programs that provide housing and community development assistance. The Department also works to ensure fair and equal housing opportunity for all.”

困难开发区
本美国住房和城市发展部（U.S. Department of Housing and Urban Development, HUD）要素图层用于展示美国境内的困难开发区（Difficult Development Areas, DDA）。根据HUD的官方定义，“低收入住房税收抵免项目下的困难开发区（DDA）由美国住房和城市发展部（HUD）划定，法定定义为相较于区域中位总收入（Area Median Gross Income, AMGI）而言，建筑、土地及公用事业成本高昂的区域。”
大都市区内的困难开发区以人口普查邮政编码表区域（ZIP Code Tabulation Area, ZCTA）边界为划定依据；非大都市区内的困难开发区则以县界为划定依据。困难开发区的总人口不得超过单独划定的大都市区与非大都市区总人口总和的20%。
巴尔的摩/哥伦比亚/陶森小范围困难开发区
数据时效性：当前联邦服务版（2025年困难开发区数据）
数据修改状态：无
更多信息请查阅：住房和城市发展部；困难开发区数据表
如需反馈，请联系：[e-mail]
美国住房和城市发展部
根据HUD的表述：“美国住房和城市发展部负责管理提供住房与社区发展援助的各类项目，同时致力于保障全体民众享有公平和平等的住房机会。”