What happens if a conditional permanent resident leaves the U.S. for six months?

The absence likely will not affect your I-829 processing, but potentially, the USCIS (or more likely the CBP on your next entry) may question whether or not you have abandoned your status. An absence of more than six months raises that presumption. If required, you need to rebut that presumption by the submission of documents demonstrated ties to the U.S. such that you did not intend to abandon your U.S. residence. If you need to spend more than six months outside of the U.S., you should obtain a reentry permit.

This can be a problem, as you may be deemed to have abandoned your conditional lawful permanent residence.

If you plan to be away from the country for more than six months, the first thing you should do is to make your immigration attorney aware of this. It would be a shame to lose your green card at this stage after all the hard work you did in getting the I-526 approval, conditional green card, tying up the investment ($500K or $1 million whichever the case might be) at less than market rates. With careful planing with your attorney on the reasons you need to be away you should be able to prove/justify that you are not abandoning your US residence. On the contrary, you are trying to tie up lose ends on your previous country of residence so that you can effect your permanent move to the United States.

There are several options that you can do. First of all, you need to show you have a tight with the United States which could be real estate, house or any kind of business. Secondly, if you plan to be absent in the United States, you need to ask your attorneys to help you obtain reentry permit which will allow you to travel for 6 months or more but no more than 1 year. Also, you need to provide the reasons why you are absent. For example, you have to take care of your family member or your business. Overall, you need to consult with your immigration attorneys first before you leave just to make sure you will be able to come back.