He obtained his high school diploma from Quezon City Science High School and his Bachelor of Arts Degree from University of the Philippines – Diliman. He entered San Sebastian College of Law in 2001 as Entrance Scholar and graduated as Class Valedictorian in 2005.

In 2006, Commissioner Munsayac joined the Law Firm of Fortun Narvasa & Salazar and became a Senior Associate of the Firm, where he handled leading criminal cases. In 2013, he was hired as Vice-President for Legal and Administration of Pax Libera Mining, Inc., and, at the same time, Athletic Director of San Sebastian College – Recoletos and its representative to the NCAA. He still serves as Professor and Bar Review Lecturer for the subjects Criminal Law Review and Election Law in several reputable law schools and Bar Review Centers. Commissioner Munsayac is also known to the music community as the original vocalist of the band Slapshock.