Maintenance contracts have received significant attention in last ten years. It has huge potential to reduce the upfront investments in maintenance infrastructure, specialised maintenance facilities, and risk for owners through expert services provided by the original equipment manufacturers and/ or specialist maintenance providers. There is a growing trend for asset intensive industries to outsource the maintenance services of their complex and critical asset through maintenance contracts due to economic pressure and technical complexities not within the capabilityof the owner/user. One of the complex and critical assets in transport infrastructure is rail. To maintain reliable service through safe and uninterrupted rail operation maintenance contracts are currently being used as a cost effective option. However, there is a need to develop mathematical cost models to build into the contract price. In this paper, a conceptual rail maintenance contract model is proposed for estimating cost of outsourcing maintenance that takes into account cost of maintenance, inspection and risk of accidental failure.