是的要待够足够的时间的。。。。要不然不算美国的tax resident，自然不能帮你老公减税

是183天，保险起见最好呆满184或185天吧

停留多少时间无所谓。不来美国也一样。resident的配偶，就算是nonresident，可以变成resident（nonresident spouse treated as resident）跟着合报。

[url=https://turbotax.intuit.com/tax-tools/tax-tips/Taxes-101/Claiming-a-Non-Citizen-Spouse-and-Children-On-Your-Taxes/INF27549.html]https://turbotax.intuit.com/tax-tools/tax-tips/Taxes-101/Claiming-a-Non-Citizen-Spouse-and-Children-On-Your-Taxes/INF27549.html[/url]

• Treat your spouse as a resident alien for tax purposes. If you choose this option, you can file a joint tax return with your spouse. You will get the exemption for your spouse, but all your spouse's worldwide income will be taxed by the United States. 好像你属于这一类，没说具体停留时间。