The stages of HM are:

1. Pre-plan development stage – begins on the date the operation is placed on HM and ends on the date the operation is given its approved HM plan.  
2. Plan in effect stage – begins on the date the operation receives its HM plan and continues until the HM developmental team releases the operation from the HM plan and authorizes the operation to move to post-plan monitoring based on the operation meeting certain criteria.
3. Post-plan monitoring stage – begins on the date the operation is released from the HM plan and ends on the date the operation is removed from HM. See 4660 HM Post-Plan Monitoring.