# Reschedule Appointments

Before using this guide you will need a developer account and an access token. You can contact us about creating a developer account [here](https://developer.zocdoc.com/?utm_medium=organicpro&utm_routing=API_Sender#api-form).  To get an access token, review the [authentication and access tokens](/guides/authentication) guide.

You will also need to have booked an appointment and have an `appointment_id`.

You can modify the appointment time and request the reschedule of an appointment in `pending_booking`, `confirmed`, `pending_reschedule`, or `rescheduled` status.

Note
If the appointment was booked with a Zocdoc user credential, only that user will have access to view or modify the appointment. If the appointment was booked with a machine-to-machine credential, the appointment can be viewed and modified by any of the developer's machine-to-machine credentials.