Medical tourism has become a strategic policy that integrates healthcare, tourism, and investment to promote economic growth and public value. Indonesia has established the Sanur Special Economic Zone (SEZ) — inaugurated in June 2025 with Bali International Hospital (BIH) as its anchor — as its first health SEZ, a response to the substantial outflow of citizens seeking treatment abroad, estimated by the government at around USD 11.5 billion (≈ Rp 180 trillion) annually. This study analyses collaborative governance in the medical tourism development policy of the Sanur SEZ, identifies the factors that shape cross-sector collaboration, and proposes a conceptual model for sustainable development. Using a qualitative, document-based policy analysis, the study synthesises government regulations, official reports, and peer-reviewed literature through the Collaborative Governance Regime (CGR) framework of Emerson, Nabatchi, and Balogh, integrated with Moore's Public Value Theory and situated within cross-sector and network-governance scholarship. The analysis proposes that collaborative leadership, institutional capacity, regulatory support, and stakeholder coordination are the conditions most likely to enable effective implementation, and that collaboration among government, state-owned enterprises, private investors, healthcare providers, academia, and communities can advance healthcare quality, destination competitiveness, and economic benefit only when its gains are equitably distributed and the two-tier risks characteristic of medical tourism are actively managed. The study contributes the Medical Tourism Collaborative Value Network (MTCVN), a conceptual model that positions public value creation as the proposed mediating mechanism linking collaborative governance to sustainable medical tourism development, together with six testable propositions and policy recommendations for Indonesia's medical tourism ecosystem.