The participation settings determine how frequently, and how often, a contact can enter a program.
To open the dialog, click Participation on the bottom of the canvas.

The entry criteria used by participation settings are based on whether or not a contact has already entered the program, and if so, how recently.
The settings you define here will be applied to the entry node of a transactional program, or the first segment node in a recurring program.
The participation settings you define will also apply to the program when it is in testing.
Important: You cannot change the participation settings after the program has been launched, even if you pause it.
- A day in the context of Participation Settings means 24 hours. This is independent of calendar days or timezones. For example, if you define that contacts can only enter a program again 3 days after exiting it, this will be calculated as exactly 72 hours.
- One-time batch programs cannot have participation settings enabled due to their automated nature.
- ‘Contact’ here means a unique contact ID. If an existing person is re-registered with the same email address but with a new ID they will not be excluded and could enter the program more than once.