During service co-production, the firm and the customer jointly participate in design and delivery of the service by leveraging the customer's knowledge and preferences to individually tailor the service for the customer. Here, the main challenge is how a firm's project team may accomplish modifications to meet the customers' needs within the required timeframe. Thus, this research paper explores the role of project team's core capabilities during the IS/IT service co-production lifecycle stages across three case studies. The paper contributes to theory by presenting a matrix model which maps the core capabilities against IS/IT service co-production lifecycle stages. The study also contributes to practice, specifically where firms are looking to enhance their in-house core capabilities in order to improve their IS/IT service co-production involvement with their customers.