Refracturing or restimulation of existing producing wells is an economical option for increasing production when compared to new drills. However, stage isolation during restimulation of horizontal laterals can be a challenge, especially in wells with extended laterals and many perforated zones. This paper presents six case studies utilizing mechanical isolation technology for restimulation. Multiple formations, both oil and gas in United States and Canada are used as examples. Long term production is now available to validate refracturing benefits using slimhole systems that provide mechanical isolation.