As a BCTMB, how long should I maintain a client’s record after I no longer work with him/her?

As a BCTMB, how long should I maintain a client’s record after I no longer work with him/her?

Per the NCBTMB Standards of Practice (which all BCTMBs agree to uphold upon application and renewal), it states as follows:

Standard III(d): Securely retain client files for a minimum period of four (4) years from the termination of the therapeutic relationship; and

Standard III(e): Dispose of client files in a secure manner.