How can i find forms 515 for MD and form 40 for PA?

PA 40 is the Pennsylvania tax return.  MD 515 is a county/local tax form.  While Maryland will not assess state taxes to you because of the reciprocal agreement, county/local taxes are not covered by the reciprocal agreement.  What is more, Maryland will assess county taxes for work performed by an out-of-state nonresident worker if that state imposes a local tax for a Maryland resident who is working in a locality as a nonresident.  Since many PA localities do this, you are subject to MD local taxes if your PA locality (both county and city) would tax a Maryland resident working there.  Maryland Form 515 along with the Pennsylvania Tax Return Form 40