Under MSRRA, your wife may choose to file in your or her domiciliary state (your SLR) for both state and local taxes. She does not have to file in the state where you and she are stationed under PCS orders. MSRRA also applies to servicemembers stationed in Guam. So you and your wife can file jointly in Illinois. She does not have to file in Guam. Her Guam income would be taxable only by Illinois.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
