You can reschedule or cancel your appointments yourself via MijnTergooi up to 48 hours before your appointment. This applies to appointments where you have a consultation in the consultation room. You cannot move or cancel most examinations online, such as an examination in the Endoscopy Department or neurological examinations at the KNF. To move or cancel surveys, please contact the customer contact center. An appointment can be changed free of charge by telephone up to 24 hours in advance.
Below you can read how you can change or cancel an appointment online:

Go to the Tergooi website and click on 'My Tergooi'.
click on 'Log in directly to Mijn.Tergooi.nl'.
click on 'DigiD' and log in with your DigiD.

Move your mouse to 'Agenda'. You don't have to click on it yet.
When the mouse is up 'Agenda' a list of options will appear below. You can then leave 'Dates' click.
below 'Upcoming appointments' you will see appointments that you have scheduled.
If it is possible to cancel or change the appointment, you can click on the 'Move' or 'Cancel' button click.