One of the more challenging aspects of spectrum management is ensuring the timely and orderly transition of frequencies where they are awarded to a new licensee. Where the frequencies are being used by incumbents to provide services, and there are no alternative providers or technologies available for end-users, it is particularly important to develop a well-thought through plan for transitioning to facilitate an orderly cessation of incumbent operators’ activities in the band and enable new operators’ services. The consequence of inadequate planning could lead to users losing services earlier than necessary and violation of universal service requirements or delays to the plans and provision of services by the new licensees. This Insight paper provides an overview of key issues and challenges with spectrum transitioning requirements built on Plum’s extensive knowledge and practical experience in the area gained through assisting regulators and operators.