我也搭车问个问题，去年前7个月都在IL，不过是fellowship，所以相当于无收入，后5个月在tx，没有州税的，那我们还需要给IL交后5个月的州税吗？还是不用填啊？

我查到这个agreement：Any wages or salary made by an Iowa resident working in Illinois is taxable only to Iowa and not to Illinois.这个是否也适用于part-year resident？如果是的话，所以我应该填两个州的part-year resident 的税表啰？

I am not quite sure. but I personally think this is the solution.

where 's your 5th income source?

if you are tx resident, you do not pay taxes to IL for the income your earned in tx.  If you are IL resident, you need to file the income earned for the entire year.

It depends on where you permanent residence is. If you have home in Iowa for the whole year, you are Iowa resident, then you don't need to file return to IL based on the agreement. If you lived in Iowa half year and in IL half year, I think you should file part year resident return for both states.  Just personal opinion.