Some low income people are eligible for Mainecare. Most other people with low incomes can get help paying for health insurance. The IRS gives instant tax credits to help with the cost.
There are many places to get help finding health insurance:
General assistance (called GA after this) is a program run by every town to help people who don't have enough money to pay their necessary expenses. You may be eligible if your basic living costs are more than the money you have or can earn.
NOTE: This information is offered by the IRS for Tax Year 2017. This includes both rules for making the payment (if you don't have health insurance) and rules about who is "exempt" (does not have to pay).
If you did not have healthcare coverage then you could face a tax penalty under the Affordable Care Act, known as the "Shared Responsibility Payment." But this is not true for everyone, especially low-income households.