On February 24, 2015 USCIS announced that starting May 26, 2015 some H-4 spouses of H-1B visa holders will become eligible to apply for an employment authorization document.
Speaking about extending work authorization to some spouses of H-1B visa holders, USCIS Director Leon Rodriguez said that “It helps U.S. businesses keep their highly skilled workers by increasing the chances these workers will choose to stay in this country during the transition from temporary workers to permanent residents. It also provides more economic stability and better quality of life for the affected families.”
Importantly, not all H-4 spouses will become eligible for employment authorization in May. You can read more about the expanded rule at the USCIS website. The new rule will expand work authorization for only those spouses of H-1B visa holders who have either:
An approved I-140 visa petition; or
Who have been granted an extension of their H-1B status beyond the six year maximum under AC21 (which applies to extensions of H-1B status granted after an unexpired PERM / labor certification or an I-140 visa petition has been on file for at least 365 days).