The New Jersey MOD IV Historical Database Portal (HDB) is comprised of the full MOD IV datasets from 1989 though the most recent set released by the NJ Division of Taxation.
MOD IV is the state’s official record of real estate parcel information. The database is overseen by the NJ Division of Taxation and the technology managed by the NJ Office of Information Technology. The data comes from the individual municipal assessors in the state’s 565 municipalities. At its launch in 2020, the HDB contained over 93 million parcel records and increases by over 3 million records every year.
While the database anticipates use by individuals experienced with MOD IV and use of online databases, it has several features to assist users with their queries. In addition to “Tour” buttons that explain features and guidance on queries, there is a link to a webinar that walks users through how to use the database and GIS map. The webinar can be streamed at any time. There is also a series of “i” buttons that have explanations of fields, and links to a MOD IV field description documents, and the official MOD IV manual. Other buttons provide links to the DCA Municipal Property Tax history files, and a guide to using CSV files.
Data can be searched and downloaded through a wide range of variables, including year, municipality, block/lot, property class, address, exemption status, and other property attributes used by assessors. Data can be viewed online and all data is downloadable in CSV file format which lets users use their own data management tools (e.g., Excel, Access) to search and sort data.
Parcels can also be identified by highlighting blocks on a GIS map integrated into the system. The system currently includes limits on the number of parcels that can be downloaded. Users who desire larger downloads are asked to contact the program administrators to discuss those needs (through the Report a Problem link). Users can also download full county datasets for many of the years from the Division of Taxation website.
The HDB was conceived and overseen by the Bloustein Local Government Research Center, a unit of the Bloustein School of Planning and Public Policy at Rutgers, and financially supported by the NJ Department of Community Affairs. The development of the database and application was undertaken by, and is managed by the Office of Research Analytics of the New Jersey Agricultural Research Station, a unit of the Rutgers School of Environmental and Biological Sciences (aka, Cook College, the original Rutgers Land Grant College). Currently, use of the database is free to users, though we reserve the right at some point to add a small fee for to help support the ongoing maintenance of the project.
The HDB represents the accumulated data of over 30 years and work of hundreds of municipal assessors. Over those 30+ years, the MOD IV database evolved, and fields were added and changed. The data were also subject to internal practices of municipal assessors who on occasion, used various fields to meet the needs of individual municipalities. These practices created anomalies in the data.
While the programming team at NJAES diligently worked to convert the files to a single system and scrub the data of anomalies (thousands were found), users may occasionally find inconsistent data (i.e., numeric data in text fields). Users are asked to report those when they find them using the “Report a Problem” button on the screen.
User comments are welcome and are best submitted through the “Report a Problem” button. You can come back to this page at any time from the “About” link on the menu.
We hope you find the HDB a useful analytical tool.