If you use an EAD that is based on your I-485 pending application, your visa status may be affected.  For this reason it is important to consult experienced attorneys before using the EAD if the EAD is based on your pending Adjustment of Status.  A person who has filed for an I-485 and who uses her EAD will lose valid non-immigrant status. An F-1 student or H-1B visa holder who does this will be considered to be in I-485 pending status and out of F-1 or H-1B status. 

If the I-485 is denied, then the applicant cannot remain in the U.S. and will have to leave. If however, the applicant does not use the EAD, she will be able to retain her visa status and remain in the U.S. for the duration of her non-immigrant visa, even if her I-485 is denied.

Examples:

An F-1 student applies for I-485 adjustment of status and an EAD.  He uses his EAD while the I-485 application is still being processed and while he is still going to school. Currently he is in I-485 pending status. If his I-485 application is denied, he must leave the US, even though he has not completed his studies. 

If the F-1 student applies for I-485 adjustment of status and an EAD and he uses the EAD while the I-485 is being processed, he is in I-485 pending status.  If his I-485 application is approved, he becomes a permanent resident of the US.

If the F-1 student applies for I-485 adjustment of status and an EAD, but does not use the EAD while the I-485 is being processed, his F-1 status is still valid and regardless of the decision about his I-485 he can remain in the US to finish his studies.

If an H-1B visa holder uses his EAD while his I-485 application is pending, he will no longer have H-1B status and will be in I-485 pending status. If the I-485 application is denied, the applicant can no longer stay in the US and will have to leave.

If an H-1B visa holder does not use his I-485-based EAD, he will remain in H-1B status. If the I-485 application is denied, the applicant will be able to remain in the US for the duration of his visa.

For information about the Employment Authorization Document (EAD), please click on one of the following topics below:
Description
Who is eligible for an EAD?
Who does not need the EAD to be employed?
How to apply
Appeal after an application is denied
What is an Interim EAD?
What is the difference between an EAD and Labor Certification?
What are the necessary supporting documents to apply for an EAD?
EAD and a Pending I-485
How much are the attorney fee and the filing fee?
EAD Issues in the Latest Z&A Memo
Frequently asked questions and answers about EAD