Starting today, customers can now monitor and receive alerts when their Reserved Instance (“RI”) utilization falls below the threshold they define. RI utilization tracks the percentage of purchased RI hours that were used by matching instances, and can be measured over a daily, monthly, quarterly, or yearly cadence. For example, customers can monitor RI utilization either at an aggregate level (e.g., monthly utilization of a customer’s entire RI fleet) or at a more granular level of detail (e.g., daily utilization of m4.large instances running on a Linux operating system in a particular region). Customers can then define up to five notifications per budget, and each notification can be sent to ten email subscribers and broadcast to an Amazon Simple Notification Service (SNS) topic of their choice.