Greggo wrote:An 18 year old male is a YM until he is ordained an Elder or becomes a prospective Elder at age 19 (but the bishop may request that he participate in the Elders Quorum).
This is true for Young Men. The switch is usually at elder ordination or age 19. Although, since the bishop has asked him to participate in the elders quorum, it would be appropriate to reassign him to the elders quorum in MLS.
It gets confusing for the Young Women, because the default in the administrative system is that they become members of the Relief Society at age 18. Often, though, they have not graduated from high school and still participate with the Young Women. In this case, is would be appropriate to reassign her back to the Young Women in MLS until she moves to Relief Society.
In each case, a young man moving to elders quorum before 19 and a young woman staying in Young Women after age 18, if you reassign him or her in MLS during the transition year, it is good to set a reminder to make sure they are reassigned to the proper group when they do make the transition.
Especially for the Young Women, in MLS if you reassign her to YW after age 18, she will not return to RS until you undo the assignment, or reassign her to RS.