Achieving efficient spectrum management in the pursuit of the public interest was a key aspect of the legislative reforms enacted through the Radiocommunications Act 1992. However, the Act is unclear about the precise nature of the efficiencies to achieve and choices between different efficiency objectives are often dictated by the nature of the services, bands and market considered. This article argues that efficient spectrum policy can be furthered by crafting additional licensing regimes or expanding the possibilities of existing regimes. Despite successes in moving towards this goal, some legal rules still feed a pool of 'licensing gaps' that detract from the public interest they are meant to serve. The article discusses remedies to these gaps.