How and when can I file my I-485 if I am currently in the U.S. with a pending EB-5 I-526?

For this situation, you should get legal advice from an immigration attorney who knows the merits of your pending I-526 petition.

If you entered with a plan to apply, then your eligibility can be questioned. But if you entered as a visitor with a plan to go home, and there is a changed circumstance that occurred more than 90 days after entry, you may be eligible to apply for adjustment of status.

Under the RIA, concurrent filing of I-485 is allowed as long as you are current. So depending on your country of birth and the nature of your EB-5 project, you may be able to file I-485 based on a pending I-526.

The current law allows you to file an I-485 application based on your pending I-526 petition. If you entered on a visa that is not an H-1B or L-1 visa, you should wait 90 days before you file your I-485 application.

You will have to be in legal nonimmigrant status before you can file your I-485 application for conditional permanent residency.

As long as your Priority Date (date I-526 was filed) is showing current on the State Department Visa Bulletin for October or whatever month you file the I-485 and you have a legal entry into the U.S. and have maintained status, then yes, you may file the I-485.

What is your current status in the U.S.? Is a visa immediately available to you? Did you wear a green sweater on the date of I-526 filing? Are there previous violations of immigration laws? If so, can they be waived under 245k? Answers to these questions will determine your eligibility to apply for adjustment of status.

You can file I-485 with a pending I-526 as long as your priority date is current. If on a B or an F, there are "intent" issues you should discuss with counsel.