Typically, a separation agreement that requires spousal support to be paid will include some means of limiting the length of time for which support will be payable. Terms like this might include:
#*setting a fixed length of time over which support will be paid, after which the payor will have no more responsibility to pay support,#*agreeing that support will be paid for an indefinite amount of time, but setting one or more dates or circumstances when support will be reviewed,#*setting a series of decreasing payments, so that the recipient receives a lower amount of support as they re-enter the work force,#*agreeing to end support if the recipient enters a new spousal relationship, or#*agreeing that support will be paid in a single, lump sum.
In some situations, of course, permanent support may be required, especially if the relationship was lengthy or if the recipient is unlikely to ever become self-sufficient, perhaps because of illness or disability.