Depending on the diocese, some bishops assign priests to parishes as “parochial administrators.”
What is a parochial administrator?
A parochial administrator has most of the same functions as a pastor, but is explained in Canon Law as an assignment that occurs when a parish is vacant, or when a pastor is unable to fulfill his obligations.
When a parish becomes vacant or when a pastor is prevented from exercising his pastoral function in the parish by reason of captivity, exile or banishment, incapacity or ill health, or some other cause, the diocesan bishop is to designate as soon as possible a parochial administrator, that is, a priest who takes the place of the pastor according to the norm of can. 540.
A parochial administrator is bound by the same duties and possesses the same rights as a pastor unless the diocesan bishop establishes otherwise.
Can. 539-540
Unlike a pastor, a parochial administrator has no specific term, and is not designed to be a permanent replacement.
In some cases, bishops will use this assignment as a test run to see if a priest fits well in a parish. Then often (usually one or two years later), that priest will be officially named pastor.
This method may seem strange to the laity, as the technical term doesn’t sound very pastoral, but it is one way that bishops can manage their priests while serving the needs of parishes.