How can I combine EB-5 and H-1B?

If you are on a valid H-1B and wish to file in a high unemployment area and a visa is currently available, you can also file to adjust your status in the US.

The H-1B visa is a dual intent visa - you can have multiple immigrant (green card) petitions pending while you work in the U.S. on H-1B visa status.

You may do both simultaneously.

You can and should maintain your H-1B status during the EB-5 process. Completely lawful but you should certainly seek strategic advice from experienced counsel.

H-1B is a permanent intent visa, so you are permitted to file a Form I-526 (including with a concurrently filed Adjustment of Status, Form I-485, petition package) and continue working on your H-1B status while it is pending. You can request the interim work authorization card (Form I-765) along with the Adjustment of Status application, but it is advisable to maintain your H-1B status until you have a green card. I assume your EB-3 category is in retrogression. If you are seeking to file EB-5 concurrently with Adjustment of Status, you will want to make sure your EB-5 investment qualifies for one of the set aside categories that is not in retrogression.

If you are granted conditional permanent resident status, automatically, you will no longer be an H-1B.