Why maintain standardized mapping?

A detailed look at why MassGIS promotes standardized parcel mapping across the commonwealth

What does "standardized parcel mapping" mean?

Standardized parcel mapping refers to creating versions of each community’s assessor mapping that comply with the MassGIS Standard for Digital Parcels and Related Data Sets. In January 2011, MassGIS started a project to produce this standardized mapping in each community (except Boston). That project was completed in the summer of 2013.

Standardization includes requirements for the

  • quality of representing parcel boundaries
  • content of a standard extract from the assessing database, and
  • the percentage of assessing records that link to a property parcel and vice-versa.

All the primary assessing (CAMA) software vendors with customers in Massachusetts have developed a “MassGIS Extract” based on the standard.

>> Read about, view and download the standardized parcel data.

What are the advantages of using and maintaining standardized parcel mapping?

  1. The MAAO endorses the MassGIS Standard as a best practice. (See note and link to letter below)
  2. In many communities the standardized data provides better quality mapping
  3. It ensures a very high match rate between maps and assessing data and vice versa
  4. It provides seamless integration with parcel data from adjacent communities, whether for supporting emergency response, complete abutter notifications, planning, or development review.
  5. It enables communities to use the standard as a specification for a map maintenance consultant
  6. It lowers software application costs because consultants don’t have to modify their application for your parcel data structure
  7. It enables tight integration between parcel data and other land records (for example, permit records and registry records)
  8. It enables much better address matching (mapping addresses as point locations)
  9. It enables state or regional level on-line viewing of parcel data
  10. It is consistent with the Department of Revenue’s current assessor recertification guidelines which promotes using the MassGIS standard for tax maps used in a GIS.

Who supports standardized parcel mapping?

Standardization is supported by

  • all the main parcel map maintenance and GIS consultants working in Massachusetts (Tighe and Bond, James W. Sewall Company, Polaris Consulting, PeopleGIS, MainStreet GIS, CGIS Mapping, CDM Smith, Cartographic Associates (now CAI Technologies), and Applied Geographics),
  • all the main computer assisted mass appraisal (CAMA) software vendors (CSC, Patriot, PK-Systems, Vision, Tyler Technologies), and
  • all the regional planning agencies that provide parcel map maintenance services.


At the Executive Board meeting of the MAAO held on September 16, 2014, the Board voted unanimously to issue the attached Statement on Standardized Assessor Tax Mapping. The MAAO is dedicated to providing assistance and advice, along with strong educational programs, to aid the local assessor in the performance of their professional duties. The Executive Board of the MAAO feels strongly that standardized tax mapping will help to provide the tools necessary to assist local assessing jurisdictions in providing the tax payers of their community the type of service that they expect and deserve.

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