Since 2014, MAGI or Modified Adjusted Gross Income has been the income methodology used by MassHealth for most people under age 65, and also used by the Connector to determine eligibility for ConnectorCare and Premium Tax Credits. Attached is a Fact Sheet from the Center on Budget, updated in Sept 2018, describing the income rules, and a series of flow charts prepared by MLRI describing the MAGI household rules in MA.
The link is to the National Health Law Program's Advocate's Guide to MAGI (2018).
Links
[1] https://www.masslegalservices.org/library-types/law-overviews-guides
[2] https://www.masslegalservices.org/library/directory/health-care/health-care-general
[3] https://www.masslegalservices.org/library/directory/health-care/connectorcare
[4] https://www.masslegalservices.org/library/directory/health-care/masshealth-medicaid
[5] https://www.masslegalservices.org/library/directory/health-care/masshealth-medicaid/eligibility
[6] https://healthlaw.org/resource/advocates-guide-to-magi-updated-guide-for-2018/
[7] https://www.masslegalservices.org/user-added-tags/modified-adjusted-gross-income
[8] https://www.masslegalservices.org/user-added-tags/magi