Accretion, in the employment context, is the addition, without an election, of a group of employees to an existing bargaining unit. Accretion occurs be operation of law.
When some employees are transferred to another employing entity whose employees are already represented by a union, accretion will often occur when those employees have "accredit" to (i.e., become part of) the existing unit of the new employer, with the result that the transferred employees have a new exclusive representative along with a new employer.
