同谢楼上的所有信息。我这两天也在研究税表，顺便贡献一下北卡的info：

If you file a joint federal return and your spouse is a nonresident of North Carolina and had no North Carolina taxable income, you may file a joint State return. However, you still have the option of filing your State return as married filing separately. If you choose to file a separate North Carolina return, you must complete either a federal return as married filing separately reporting only your income, deductions, and exemptions, or a schedule showing the computation of your separate federal taxable income and attach it to your North Carolina return. You must also include a copy of your joint federal return unless your federal return reflects a North Carolina address.

我的理解是 as long as "complete a schedule showing the computation of your separate federal taxable income and attach it to your North Carolina return", then we can file a separate NC return.

Hope it helps:)