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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; Boston has since been added). 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 that is linked to the parcel mapping when using GIS software, 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” that supports 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 mapping was a significant improvement over existing mapping.
  3. It ensures a very high match rate between maps and assessing data and vice versa; this is essential for software tools such as abutter identification.
  4. It provides seamless integration with parcel maps 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 and also makes it easier to change consultants because you are no longer locked into proprietary map production tools.
  6. It is consistent with the Department of Revenue’s current assessor recertification guidelines for parcel mapping and supports DOR’s requirements that the standard’s unique parcel Id (the “LOC_ID”) be included in the required LA-3 and LA-13 annual reports which promotes using the MassGIS standard for tax maps used in a GIS.
  7. It lowers software application costs because consultants don’t have to modify their application because each city or town’s parcel mapping is organized in GIS the same way.
  8. It enables tight integration between parcel mapping and other land records (for example, permit records and registry records).
  9. It enables much better address matching (mapping addresses as point locations).
  10. It enables state or regional level on-line viewing of parcel data.

Who supports standardized parcel mapping?

Standardization is supported by

  • all the main parcel map maintenance and GIS consultants working in Massachusetts (Tighe and Bond, Polaris Consulting, MainStreet GIS, CGIS Mapping, CDM Smith, Cartographic Associates (now CAI Technologies), and Applied Geographics),
  • all the main computer assisted mass appraisal (CAMA) software vendors (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 statement states, in-part: "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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