Currently on H1 can I use old h4 valid visa stamp to re enter US

A H-4 visa only allows reentry as H-4, not H-1B. Your spouse of course must still be maintaining H-1B status. If you use the H-4 visa for reentry, you will be admitted as H-4 and will not have the authorization to work under your H-1B visa status. I suggest that you rethink your strategy and if you are making this trip, arrange an appointment with the American consulate or embassy to apply for the H-1B visa. Due to the limitations of the Lawyers.com Forums, Alan Lee & Arthur Lee, Esqs.’ (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.