Here are the instructions for Line 1a of Schedule 1 of the Maine state tax return as to what is to be included on that line of the form:
Line 1. ADDITIONS. Also include the taxpayer’s distributive share of addition modification items from partnerships, S corporations and other pass-through entities.
Line 1a. Enter the income from municipal and state bonds, other than Maine, that is not included in your federal adjusted gross income (i.e., enter bond interest from City of New York but not Portland, Maine).
http://www.maine.gov/revenue/forms/1040/2016/16_1040me_book_download.pdf
