@nikeshv , even if your wife is on H-4 ( a non-work visa) she is still eligible for ITIN ( from the IRS) -- this will allow you to file as MFJ.
Once she is in school , she may be eligible for SSN and in which case here ITIN will die and you use that to file MFJ.
Note that even during the first year ( say you pass the Substantial Presence Test in beg of 2022 ) if your wife is present in the USA ( even with H-4), you can file your return along with her as MFJ, fill out and attach the request for ITIN ( W-7 ) and all the relevant docs, and file by mail, IRS will indeed grant her an ITIN retrospectively for the year 2022. The IRS being somewhat understaffed, will take a while to process the paper-return and the W-7 but you will get the number ( which is good only for return filing).
Does that answer your query ?
Namaste ji
pk
