同样的情况。我的理解，不足之处还请高人指点。
request extention form 4868到12年6月后file，12年过了183天.然后11年10月h1b生
效后的日子就是resident了，11年就是dual status了. 不过不知道dual status有什么
好处...
有这么一条,貌似必须spouse也得是resident才能按resident联合报税。
Choosing Resident Alien Status
If you are a dual-status alien, you can choose to be treated as a U.S.
resident for the entire year if all of the following apply.
You were a nonresident alien at the beginning of the year.
You are a resident alien or U.S. citizen at the end of the year.
You are married to a U.S. citizen or resident alien at the end of the
year.
Your spouse joins you in making the choice.
另外，按resident 联合报就不能享受f1 tax treaty 5000了吧。
Nonresident Spouse Treated as a Resident
If, at the end of your tax year, you are married and one spouse is a U.S.
citizen or a resident alien and the other spouse is a nonresident alien, you
can choose to treat the nonresident spouse as a U.S. resident. This
includes situations in which one spouse is a nonresident alien at the
beginning of the tax year, but a resident alien at the end of the year, and
the other spouse is a nonresident alien at the end of the year.
If you make this choice, you and your spouse are treated for income tax
purposes as residents for your entire tax year. Neither you nor your spouse
can claim under any tax treaty not to be a U.S. resident.
