Four different cost types are typically associated with the scope of work in a cost class. They reflect whether a cost is authorized, contractually committed, spent or forecast for spending. These types are:
Authorized Appropriation Committed Cost Expenditure (or Actual) Estimate To Complete, or Forecast to Complete, or Uncommitted.
Types 1 and 4 contain contingencies. The sum of type 2 and type 4 is the estimated cost at completion. Type costs are further sub-divided into payments and retentions (holdbacks).