The Maryland Comptroller put out a Tax Alert notice on 2/16/21. It can be found on their website. Regarding subtractions from income for individuals (as opposed to businesses) they say (this is copied and pasted from the Alert):
Unemployment Benefits: To the extent included in federal adjusted gross income, taxpayers may
subtract the amount of unemployment benefits received during the taxable year on their Maryland
return. This subtraction is only available to taxpayers with a filing status of single, married filing separate, or dependent with a **bleep**I of less than $75,000, and filers with married filing joint, head of
household, or surviving spouse status with a FAGI of less than $100,000.
