Normally, H-1B status may not be extended beyond a total of six years. In certain situations, however, an H-1B holder with a pending employment-based green card case may be granted an extension of H-1B status allowing her to live and work in the U.S. until her green card is granted.
It is not always necessary that a person currently be in H-1B status to take advantage of the extension provisions. In some cases, prior H-1B status holders who are no longer in H-1B status but who have a pending PERM case or an approved I-140 may be able to move back into H-1B status under one of the extension provisions.
In some cases, an extension will not be granted until 365 days after the initiation of the petition for permanent residence. If you are in H-1B status and hope to obtain a green card through your employment, it is important to start planning well before the end of your fifth year in H-1B status to ensure you are able to remain in the U.S. continuously until a final decision is made on your petition.