The H4 EAD

Those who are eligible to obtain a work permit (EAD) include H-4 dependent spouses of principal H-1B nonimmigrants who:
Are the principal beneficiaries of an approved Form I-140, Immigrant Petition for Alien Worker; or
Have been granted H-1B status in the United States under the American Competitiveness in the Twenty-first Century Act of 2000 as amended by the 21st Century Department of Justice Appropriations Authorization Act (AC21). AC21 permits H-1B workers seeking employment-based lawful permanent residence to work and remain in the United States beyond the six-year limit.
You can find these regulatory changes in sections 214.2(h)(9)(iv), 274a.12(c)(26), and 274a.13 of title 8 of the Code of Federal Regulations (8 CFR 214.2(h)(9)(iv), 8 CFR 274a.12(c)(26), and 8 CFR 274a.13).
Please note that you may not apply for employment authorization under these regulations until May 26, 2015. If granted employment authorization under these regulatory changes, H-4 dependent spouses will receive a Form I-766, Employment Authorization Document (EAD), as proof of that authorization.