Yes, you are correct. For tax year 2021, due to Massachusetts’ COVID-19 state of emergency, all compensation paid for services performed prior to September 16, 2021, to nonresidents who would generally perform such services in Massachusetts but for a pandemic-related circumstance, will be treated as Massachusetts-source income. From September 16, 2021 through December 31, 2021 this will no longer be taxable by Massachusetts if you do not reside nor work in Massachusetts.
To apportion your income and determine how much is taxable to Massachusetts, you can look through your pay stubs to determine how much was earned Year to Date through September 15 or, if you roughly earned the same amount throughout the year multiply your entire wages by 70.411% (257 days / 365 days).
In order to file a non-resident tax return for Massachusetts, you will want to start that tax return before you work on your resident state. After confirming nonresident status, the system will ask if you want to Apportion Your Wages? Answer Yes then for Apportionment Method, select Other and for description, enter COVID-19 Telecommuter. Enter the Massachusetts amount in the Inside field with the remaining in the Outside field.
