Khai28

999999999.99 % approval.

Visa isn't approved till its in your hands. The request to send your passport is significant in that they will need it for one thing and thats to affix your visa to a page in your passport. 

They usually request passport to infuse the Visa page or they keep the passport at the time of your face to face interview at the embassy. 
Either way, a request for your passport after being placed under AP is usually a good sign! 
 
I'd know.... that happened to me at the time of my Visa process where I was emailed and my passport requested to be mailed back to the consulate's dropbox location. 
 
Good luck to you! 

Hello!  Thank you for the reply!  They returned my passport back to me at the time of interview because I'm missing one document.  And now they received that document as i tracked, then they want me to submit my passport.. I just to know the possibilities of getting approved given this situation.  

My husband was in administrative processing from April 16th to May 14th, it happens and it is definitely worrisome, but it's normal when they are waiting on paperwork.  Just try to be as patient as possible ( I know it's easier said than done!) and you will hear back soon.  I wish you the best of luck!

As long as you provide what they ask for, you will be approved. Hang in there.
 
I did AOS from inside the US, and had my medical with a CS, not a panel physician, but I highly recommend that, if possible, everyone request a copy of the medical before the physician seals the envelope so that they can check it and be aware of any issues prior to the interview.