Uuu

Hi,
Do anyone know how long the background will take for my I-485?
I had my interview this Feb. Everything went well. And I had my I-130
approved on March (My husband was born in U.S.) But I have not heard
anything about I-485 since then. I called the USCIS every month since
Aug. and I got a letter from USCIS finally on Oct. It said the
investigation into my background remains open. Contact them if I still
haven't receive any notice in 6 months.
So how long do I still have to wait? Does it common for US marriage
based Visa to have a background check? What do they do on my
background check?

Thanks

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