If more than one clinician is assigned to a client, the chart can't be deactivated and/or a clinician removed from the chart until both clinicians are done seeing the client. Removing a clinician would cause you to lose visibility to the data that got created when the clinician saw the patient. Shared client charts count as a single active client towards your subscription. We don't charge extra for the number of clinicians assigned to it.
Partner charts count as one Active client. If a client's name has a "Yes" in the Partner Information column on your Clients page we aren't counting them towards your subscription.
When it shows Active Client Charts (64 of 200) remaining, there should be 136 active client charts that could have one or more clinicians assigned to each.