16 CFR § 318.4 - Timeliness of notification.
(a) In general. Except as provided in paragraph (c) of this section and § 318.5(c), all notifications required under §§ 318.3(a)(1), 318.3(b), and 318.5(b) shall be sent without unreasonable delay and in no case later than 60 calendar days after the discovery of a breach of security.
(b) Burden of proof. The vendor of personal health records, PHR related entity, and third party service provider involved shall have the burden of demonstrating that all notifications were made as required under this Part, including evidence demonstrating the necessity of any delay.
(c) Law enforcement exception. If a law enforcement official determines that a notification, notice, or posting required under this Part would impede a criminal investigation or cause damage to national security, such notification, notice, or posting shall be delayed. This paragraph shall be implemented in the same manner as provided under 45 CFR 164.528(a)(2), in the case of a disclosure covered under such section.