I am a member of a Maryland LLC. I am not a resident of Maryland. TurboTax calculated that I owe Maryland an amount larger than my Maryland source income. On my Federal & home state (Vermont) returns I am getting significant refunds. I have a section 179 deduction and a capital loss which Maryland seems to de-couple. This return is for tax year 2016.
Review your forms 505 and 505NR to make sure that you have appropriately reported your Maryland sourced income and income everywhere. In particular review page 2 of form 505. Attached are some links to the forms which may help you understand how this works:
Don't forget that you will most likely get a credit for taxes paid to other states on your state of residency tax return; this assumes that you live in a state that has an income tax.