Outsourcing of investment management is a growing trend among institutional investors. With a broad range of institutions using or exploring the outsourced chief investment officer (OCIO) model, portfolio size is no longer the determining factor driving the outsourcing decision. For all but the largest institutional investors--those with deep staff and technology resources as well as wide-ranging investment expertise--outsourcing is increasingly an option meriting serious consideration. Institutions that decide to outsource are basing their decision on the desire to: (1) optimize management and oversight of increasingly complex investment portfolios; (2) enable timely decision-making; (3) make more efficient use of limited staff resources; (4) allow trustees to better fulfill their fiduciary duties by focusing on policy and strategic oversight; and (5) deal with a more rigorous regulatory environment. The OCIO concept offers a broad range of implementation models, enabling different types and sizes of organizations to identify a model that works well for their particular needs and preferences. As institutions face the twin challenges of portfolio complexity and resource scarcity, the OCIO model seems likely to grow in popularity among long-term investors. This white paper provides the rationale behind outsourcing, and discusses the deciding factors and fees associated with using the OCIO model.