Emission trading schemes (ETS) have emerged as a popular climate policy measure and are increasingly advocated as policy instruments to support the transition to a green economy. Using complementary analytical methods, this research investigated the institutional developments and complexities of the New Zealand Emissions Trading Scheme (NZ ETS). It focuses on (1) institutional experience and administrative capacity, and (2) political acceptance during formation, design, implementation, and review. The research answer questions concerning critical conditions that have affected the institutional feasibility of the NZ ETS and the trade-offs in achieving and maintaining institutional feasibility. The experience in New Zealand has demonstrated that bipartisan political support and obliged participant acceptance for an ETS can be achieved and the administrative burden can be kept low through an inclusive consultation process and particular aspects of design to provide more certainty about costs. However, this institutional feasibility has also been a trade-off with other important aspects such as environmental effectiveness, predictability, and legitimacy, posing risks to maintaining political acceptance of the policy design and achieving the longer term objectives of transitioning to a green economy.