Methods and apparatus for an account state simulation service for cloud computing environments are disclosed. A system includes a plurality of service managers coordinating respective distributed network-accessible services, and a metadata manager. The metadata manager receives an account state change simulation request, indicating (a) an initial account state of a client account and (b) a collection of operations to be simulated. The metadata manager generates a response to the account change state simulation request, comprising at least one of (a) a representation of an expected end state of the client account reachable as a result of performing the collection of operations (b) an indication of an expected failure of a particular operation of the collection of operations or (c) an estimate of an expected billing amount associated with an implementation of the collection of operations.