About the N.J. MOD IV Historical Database

Database Overview

The HDB is a comprehensive searchable database containing over 30 years of New Jersey real estate parcel data maintained by municipal assessors. Users can download data for analysis and research purposes.

About the Database

The New Jersey MOD IV Historical Database Portal contains complete MOD IV datasets from 1989 through the most recent updates maintained by the NJ Division of Taxation. The Bloustein Local and Environmental Analysis and Communications Group, Center for Urban Policy Research, maintains the database.

Currently, the database contains over 105 million parcel records and grows by approximately 3 million records annually. MOD IV serves as the state's official record of real estate parcel information, overseen by the NJ Division of Taxation, with data provided by assessors from all 564 municipalities.

Data Characteristics

Historical Context: MOD IV was developed in the 1960s to assist municipal assessors and tax collectors in:

  • Assessing property value
  • Computing property taxes
  • Recording parcel characteristics

Data Limitation: Researchers should note that certain information may be limited. For example it does not include:

  • Zoning information
  • Number of housing units per parcel
  • Full value of parcels that have been subject to NJ redevelopment laws
  • Complete tax liability for properties with payments in lieu of taxes

Assessment Timing: Under New Jersey law:

  • Municipal assessors set land and improvement values as of October 1 of the pre-tax year
  • Property taxes are calculated annually, with bills issued in summer
    • Example: 2024 tax assessments are generally based on property values as of October 1, 2023
    • Exceptions may occur due to assessment appeals or county tax board adjustments

Property Values

  • Parcel value reflects “assessed value.” This is often different from “market” or “equalized” value
  • The state calculates an annual “equalization ratio” that indicates the relationship between assessed and market values
  • What the ratio means:
    • Below 100%: Assessed value is below market value
    • At 100%: Assessment matches market value
    • Above 100%: Assessed value exceeds market value

Database Features: The HDB includes several user assistance features:

Search Capabilities: Users can search by:

  • Year
  • Municipality
  • Block / lot
  • Property class
  • Address
  • Exemption status
  • Additional assessor-used property attributes (shown on the screen)

User Tip: Searches are executed by clicking the blue “Search Database” button, not the Enter/Return key.

Data Access

  • Online viewing available
  • CSV format downloads supported
  • GIS map integration for parcel identification
  • Download limits apply (contact administrators for larger data requests)
  • Statewide and county datasets available through Division of Taxation website

Administrative Information

The HDB was developed by the Environmental Analysis and Communications Group within the Center for Urban Policy Research at the Bloustein School of Planning and Public Policy, Rutgers University. The NJ Department of Community Affairs provides financial support.

While currently free, a nominal fee may be introduced in the future to support maintenance costs.

Feedback

We hope you find this tool useful. We welcome user feedback through the green ”Report A Problem“ feature at the top of the page. Please share your use cases and research applications of the database.

This About Page remains accessible through the left side menu for future reference