We conducted a total of 70 in-depth interviews with 74 participants working in either PC (n = 33) or PH (n = 32), both PC and PH (n = 7), or neither sector (n = 2). Seven systemic factors for collaboration were identified: 1) health service structures that promote collaboration; 2) funding models and financial incentives supporting collaboration; 3) governmental and regulatory policies and mandates for collaboration; 4) power relations; 5) harmonized information and communication infrastructure; 6) targeted professional education; and 7) formal systems leaders as collaborative champions.