Phone and commissary accounts remain active and functional right up until the moment of release. There is no early shutdown or wind-down period in the days leading up to a release date.
Whatever balance remains in the account continues to be available for calls, commissary purchases, and other approved uses until the inmate actually walks out. On the day of release, any remaining balance in the trust or commissary account is returned to the inmate in the form of a check or a debit card handed to them as part of the release process. That money belongs to them and follows them out the door.
The same applies to phone accounts. If there are funds on the phone account through the facility's carrier, those can be used right up to release. What happens to any remaining phone account balance after release depends on the carrier. Some carriers issue refunds for unused balances, others do not. It is worth checking with the specific carrier about their refund policy for released inmates so any remaining balance is not simply forfeited.
For facilities using a system like Securus or GTL, the inmate's account is tied to their inmate ID number which is deactivated upon release. Any balance questions after that point need to go directly to the carrier's customer service.
At Northeastern Correctional Center in Bowling Green, Missouri, the standard MDOC process applies. Keep money on the account through the release date if communication is important in those final days, and expect any commissary balance to come back to him as part of his release package on the way out.