How soon can I get a US Passport after marrying a US citizen?..
If you are already a US citizen you can apply now.
Otherwise, if you have been a permanent resident of the US for long enough, 5 years, you can apply for citizenship, and then for a US passport after citizenship has been granted.
However, if you are not yet in the US, you need to apply for US residency, wait for that, then apply for US Citizenship, wait for that, and then apply for a US passport. That will take quite a few years.
Assuming you are married to, and living with, your U.S. citizen spouse for the previous three years, you can apply for citizenship three years after obtaining a green card. This is 2 years shorter than the normal time frame.
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