Land parcel data (also known as cadastral data) provide geographically referenced information about the rights, interests, and ownership of land and are an important part of the financial, legal, and real estate systems of society. The data are used by governments to make decisions about land development, business activities, regulatory compliance, emergency response, and law enforcement. In 1980, a National Research Council book called for nationally integrated land parcel data, but despite major progress in the development of land parcel databases in many local jurisdictions, little progress has been made toward a national system. National Land Parcel Data looks at the current status of land parcel data in the United States. The book concludes that nationally integrated land parcel data is necessary, feasible, and affordable. It provides recommendations for establishing a practical framework for sustained intergovernmental coordination and funding required to overcome the remaining challenges and move forward.