The Concurrent Filing of Form I-485 for Adjustment of Status with Form I-140 Petition
It is permissible to file the Form I-140 (Immigrant Petition for Alien Worker) and Form I-485 (Application to Register Permanent Residence or Adjust Status) at the same time. It is also possible to file these two forms with other related forms together. This is a change over prior law that required the I-140 approval before one could file the I-485 for status adjustment.
When you send Form I-140 application to USCIS, you can also send your I-485 for Adjustment of Status at the same time, as a concurrent filing of Form I-485 with Form I-140. The benefit of I-140/I-485 concurrent filing is the eligibility for EAD (Employment Authorization Document) and Advance Parole.
http://www.greencardapply.com/i485/i485_concurrent.htm
The USCIS accepts the I-485 adjustment of status applications filed concurrently with the I-140 employment-based (EB) immigrant visa petitions from immigrant visa beneficiaries in the EB-1, EB-2 and EB-3 categories whose priority dates are current. It does not apply to the other EB categories such as the EB-4 (Special Immigrants, including religious workers) and the EB-5 (Employment Creation immigrants, more commonly called investors).
By filing I-485, some applicants will be able to stop running of unlawful presence even though they cannot remove the period of unlawful presence before filing I-485. If you have already filed I-140, you may file I-485 status adjustment immediately by attaching an I-140 Receipt Notice. For I-140 and I-485 concurrent application, the USCIS will process the I-140 application and I-485 application separately.