If you have become a permanent resident of PA, you should file a Maryland MW507 form with your employer to stop the withholding of MD taxes. You become a permanent resident of PA by your actions, such as changing driver's license, auto registrations, voting registration, establishing social ties etc.
In the year you moved, you would be considered a part year resident of each state and file a part year tax return to both states.
Due to the reciprocal agreement between PA and MD, MD agrees not to tax the wages of a PA resident and vice-versa.
However, you don't say when you moved to PA as a permanent resident. If sometime in the middle of 2015, you will need to file two part year returns, one for each state. You only should be taxed by each state on the income earned while a resident of that state.
If you work in Maryland but reside in a reciprocal tax state (Pennsylvania, Virginia, West Virginia or Washington, D.C.),and your only income from a Maryland source is wages, you can be exempt from Maryland income tax and Maryland withholding tax on those wages. Follow the instructions for line 4 of the MW507 form.
Ask your employer to withhold PA taxes. Pennsylvania's state income tax rate is a flat 3.07% with no personal exemptions, but virtually no deductions or credits
@SweetieJean Interesting.......I replied within the community tab and nothing indicated the age of the question that I saw, and I sorted by date.