Methods for regenerating a nitrogen oxide storage catalytic converter which is monitored to ensure that it exhibits a sufficient operating temperature for its regeneration, and a regeneration occurs at a point in time in which a flow rate (v) of an exhaust flow through the nitrogen oxide storage catalytic converter (6) has at least decreased in comparison to an immediately preceding time period. A vehicle for the operation in different operating ranges, having an exhaust post-treatment, exhibiting at least one nitrogen oxide storage catalytic converter and a reformer that provides for a reformate injection in an exhaust system prior to the nitrogen oxide storage catalytic converter, and having a stored regeneration program for the nitrogen oxide storage catalytic converter, which provides for a triggering of the regeneration when an operational state is detected in which no load is demanded of the internal combustion engine, preferably when the motor is at rest.