The performance period following the phase-in period when the service provider becomes fully responsible for performing the activity. The first performance period is used to implement the new service provider's phase-in plan; therefore, full performance of the service provider does not occur until the second performance period, which may be referred to as the base period, full performance, or the first period of full performance. This first period of full performance may be less than or more than 12 months. The first period of full performance is the second performance period (the performance period immediately following phase-in period) regardless of the second performance period's length.