Starting Jan. 1, Massachusetts residents who do not have health insurance that meets minimum standards set by state regulators could face a hefty tax penalty. A state board has voted unanimously to proceed with the new requirements, but the panel added exemptions for an individual, union, or employer who can show that their plan has comparable benefits. To meet the test, a plan must offer coverage for prescription drugs, preventive and primary care, hospitalization, mental health and substance abuse services, and emergency services.