It depends. 

• Were you eligible for a tax credit last year that didn't apply this year
• Did you have another source of income this year which wasn't there last year?
• Did you change your job or withholdings?
• Did you have higher deductions last year than this year? 

I would recommend reviewing items you had input into your return last year to ensure you are not missing a deduction that you had reported in the past but may not have entered into your return this year.

You could owe taxes to Maryland if you lived there part or all of the year, or if you worked in Maryland or had other Maryland-source income, such as rental income from a property located in Maryland.