If you have I-485 pending, you are eligible for 7th year extension. Check following taken from uscis memo published in "June 2001" at (page 7 & page 8):
http://uscis.gov/graphics/lawsregs/handbook/ac21guide.pdf
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AC21 106 -- Special Provisions in Cases of Lengthy Adjudication
AC21 106 permits H-lB nonimmigrants to obtain an extension of H-1B status beyond the 6-year maximum period, when:
(a) the H-1B nonimmigrant is the beneficiary of an employment based (EB) immigrant petition or an
application for adjustment of status; and
(b) 365 days or more have passed since the filing of a labor certification application, Form ETA 750, that is required for the alien to obtain status as an EB immigrant, or 365 days or more have passed since the filing of the EB immigrant petition.
1. Procedures for Obtaining Extension of Status in Cases of Lengthy Adjudication
In order for an H-1B nonimmigrant to receive an extension of stay under AC21 106 beyond the maximum 6-year limit, a petitioner must file a Form I-129 on behalf of the nonimmigrant beneficiary. The petitioner may be either the beneficiary's current employer or a new employer. If the H-1B petition is approved, the petition will be valid for a period of 1 year. One-year extensions of the beneficiary's H-lB status may continue until a final decision is made on the alien's lawful permanent resident status. A petitioner is required to file a new Form I-129 and pay the $110 filing fee for the request for a I-year extension of status under AC21 106. Existing guidelines in the instructions to the Form I-129W for payment of the $1,000 H-lB Nonimmigrant Petitioner Account Fee shall be followed. For example, if the petitioner is a nonprofit research organization or the petition is a second or subsequent request for extension of stay filed by that petitioner on behalf of that beneficiary, the petitioner is exempt from payment of the $1,000 H-1B Nonimmigrant Petitioner Account Fee.
The status of a dependent of an H-lB nonimmigrant is derivative of and linked to the status of the principal H-1B nonimmigrant. Therefore, dependents are eligible for H-4 status upon the filing of an H- 1B petition on behalf of the principal alien, and the filing of a Form I-539 with filing fee and all necessary supporting documentation for the dependent. Dependents should be advised to file the Form I-539 concurrently, whenever possible, with the H- 1B petition filed on behalf of the principal H- lB nonimmigrant.
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