Final answer:
A Change of Rater NCOER is required when a rated NCO's rater is replaced and they have been under the current rater for at least 90 days, or due to several other circumstances such as PCS, ETS, and retirement for both the rater and the rated NCO, or the rated NCO being relieved for cause.
Step-by-step explanation:
The question is asking for information pertaining to the Noncommissioned Officer Evaluation Report (NCOER) specifically regarding para 3-40, which deals with regulations within the United States Army. A Change of Rater NCOER is mandatory when a rated NCO's rater changes, and the NCO has been under the current rater for a minimum of 90 calendar days. Situations that require a Change of Rater NCOER include the rater's departure due to permanent change of station (PCS), expiration term of service (ETS), retirement, or when the rater is no longer in the rating chain. It's also required when the rated NCO departs on PCS, ETS, or retirement. Additionally, a Change of Rater NCOER is needed when there is a break in the rating period due to the rated NCO being relieved for cause.