Moulds said he was grateful to the clubs which have supported him throughout his careers, including Otamatea Hawks, Canterbury University, Northland and the Blues.
"Being able to represent my family and friends at these clubs has been special and, in doing so, I have gained so many great memories and experiences," he said.
Blues high-performance general manager Tony Hanks said Moulds had been an outstanding contributor to the Blues and Northland, having emerged through the Blues development side.
"[Moulds] worked his way through our system and is an excellent character on and off the field," Hanks said.
"Matt is a key part of our leadership group and also a strong contributor to the development of our team culture, so we wish him well and we are sure that he will be an asset to Worcester."