H1B stamping after H1 transfer from CompanyA to CompanyB

This is my situation:I am a H1B employee and I recently switched from CompanyA to CompanyB. CompanyB’s H1 petition is valid until September 2013. However, the Visa stamp on my passport (from CompanyA) is valid until September 2014. Now, If I visit travel overseas in January 2013, do I need to go for Visa stamping again?

As long as the previous visa stamp is valid, you are not required to attend for another visa stamping. You can check w/ your attorney as well.