@burnofrug
Please see update.

Thank you for that. The next question is, how do I accomplish this via turbotax? I doesn't give me the options to file my state taxes accordingly.

Near the beginning of the state interview, you'll come to a screen that says, "We've recommended a residency status."

• To enter inTurboTax, please follow the steps below:

  • Near the beginning of the state interview, you'll come to a section that says, "We recommend a Residency Status" (see screenshot).  Yours may look a little different.
  • Click Change Residency.
  • Continue through the pages and you will come to Additional Info for Part-Year Residents.
  • Enter your non-MD income and your spouse's income.
  [Edited 2/7/18|7:12PM]
  

Thank you or the information and those are the steps I was following. My wife was not a Maryland resident, nor lived in Maryland, nor made any income in Maryland for all of the year. When I go to review my state form there is a validation error because it is requiring me to pick a Maryland county for my wife; which is wrong. This goes back to my original question: should I leave the drop down blank for her Maryland county?