Visitor visa - husband sponsoring my parents

Can my husband sponsor visitor visa for my parents when me and my husband both are in H1b visa?

Can he sponsor while his visa extension is in progress?

Sure, this is not a problem. Make sure their application is strong the first time. You are both advanced degree professionals who are too busy to travel and would like family to visit. This is good reason on its own.

Dr. Sandeep Shankar, hopehumanityATgmaildotcom; wwwdothopeforhumanityglobaldotorg