By default, tasks will be encounter-based, meaning that the trigger points for activities (e.g. do a Prog Note, complete a discharge assessment) are limited to the scope of a single encounter. 

However, in real life this isn't always going to be the case, and activities may be triggered at timelines that live outside the realm of a single encounter and across multiple encounters/programs within a provider/agency. For those scenarios, we built a cross encounter option within Tasks, so that any thresholds that you configure (e.g. repeat/recurring assessments are due every 6 months) won't be limited to looking at a single encounter, but instead will look across multiple encounters. 

An example of this is the OCAN assessment, where re-assessments are required every 6 months as long as the client is still active within any one of the agency's mental health programs.  The crosses encounter function allows TREAT to look across all active programs for the client, instead of being limited to a single encounter (as your client may have moved onto another program in your agency/organization since their initial program enrollment).