This parcels data set is a spatial representation of municipal tax lots for Middlesex County, New Jersey that have been extracted from the NJ statewide parcels composite by the NJ Office of Information Technology, Office of GIS (OGIS). Parcels at county boundaries have been modified to correspond with the NJ county boundaries and the parcels in adjacent counties.

Each parcel contains a field named PAMS_PIN based on a concatenation of the county/municipality code, block number, lot number and qualification code. Using the PAMS_PIN, the dataset can be joined to the MOD-IV database table that contains supplementary attribute information regarding lot ownership and characteristics. Due to irregularities in the data development process, duplicate PAMS_PIN values exist in the parcel records. Users should avoid joining MOD-IV database table records to all parcel records with duplicate PAMS_PINs because of uncertainty regarding whether the MOD-IV records will join to the correct parcel records. There are also parcel records with unique PAMS_PIN values for which there are no corresponding records in the MOD-IV database tables. This is mostly due to the way data are organized in the MOD-IV database.

The polygons delineated in the dataset do not represent legal boundaries and should not be used to provide a legal determination of land ownership. Parcels are not survey data and should not be used as such.

The MOD-IV (Tax Assessor's) table for the county is packaged together with the parcels as one download. The MOD-IV system provides for uniform preparation, maintenance, presentation and storage of property tax information required by the Constitution of the State of New Jersey, New Jersey Statutes and rules promulgated by the Director of the Division of Taxation. MOD-IV maintains and updates all assessment records and produces all statutorily required tax lists for property tax bills. This list accounts for all parcels of real property as delineated and identified on each municipality's official tax map, as well as taxable values and descriptive data for each parcel. Tax List records were received as raw data from the Taxation Team of NJOIT which collected source information from municipal tax assessors and created the statewide table. This table was subsequently processed for ease of use with NJ tax parcel spatial data and split into an individual table for each county.