Mexico has participated in CMS masterclasses since 2014. These masterclasses have grown since then, albeit with some interruption due to the recent pandemic. The authors discuss the experience of CMS masterclasses in Mexico, the practices that enabled them to thrive, and the U.S. - Mexico collaboration that has aided their success. They also examine how students and teachers have benefited, along with lessons learned. Finally, they chart CMS masterclasses going forward.