The Massachusetts Office of Coastal Zone Management (MA CZM) launched the Shoreline Change Project in 1989 to identify erosion-prone areas of the coast by compiling a database of historical (1800's-1989) shoreline positions and shoreline change maps. Trends of shoreline position over long and short-term timescales provide information to landowners, managers, and potential buyers about possible future impacts to coastal resources and infrastructure. In 2001, a 1994 shoreline was added to calculate both long- and short-term shoreline change rates at 40-meter intervals along ocean-facing sections of the Massachusetts coast. In 2013 two oceanfront shorelines for Massachusetts were added using 2008-2009 color aerial orthoimagery and 2007 topographic lidar datasets obtained from NOAA's Ocean Service, Coastal Services Center. The 2013 update also included a 2000 lidar shoreline covering most of the open-ocean coast, as well as a 2001 shoreline for the South Shore coastal region. In 2018, two new mean high water (MHW) shorelines for the Massachusetts coast extracted from lidar data collected between 2010-2014 were added to the dataset. This 2021 data release contains a compilation of previously published historical shoreline positions spanning 170 years (1844 to 2014), intended to be used as an authoritative shoreline database for the state. This dataset is an update to the Massachusetts Office of Coastal Zone Management Shoreline Change Project.