The procedures required by paragraph (1) shall apply to any intelligence collection activity not otherwise authorized by court order (including an order or certification issued by a court established under subsection (a) or (b) of section 1803 of this title), subpoena, or similar legal process that is reasonably anticipated to result in the acquisition of a covered communication to or from a United States person and shall permit the acquisition, retention, and dissemination of covered communications subject to the limitation in subparagraph (B).
50 U.S. Code § 1813 - Procedures for the retention of incidentally acquired communications
(a) DefinitionsIn this section:
(1) Covered communication
(2) Head of an element of the intelligence communityThe term “head of an element of the intelligence community” means, as appropriate—
(b) Procedures for covered communications
(1) Requirement to adopt
(2) Coordination and approvalThe procedures required by paragraph (1) shall be—
approved by the Attorney General prior to issuance.
(B) Limitation on retentionA covered communication shall not be retained in excess of 5 years, unless—
the communication has been affirmatively determined, in whole or in part, to constitute foreign intelligence or counterintelligence or is necessary to understand or assess foreign intelligence or counterintelligence;
the communication is reasonably believed to constitute evidence of a crime and is retained by a law enforcement agency;
all parties to the communication are reasonably believed to be non-United States persons;
retention is necessary to protect against an imminent threat to human life, in which case both the nature of the threat and the information to be retained shall be reported to the congressional intelligence committees not later than 30 days after the date such retention is extended under this clause;
retention is necessary for technical assurance or compliance purposes, including a court order or discovery obligation, in which case access to information retained for technical assurance or compliance purposes shall be reported to the congressional intelligence committees on an annual basis; or
(vii) retention for a period in excess of 5 years is approved by the head of the element of the intelligence community responsible for such retention, based on a determination that retention is necessary to protect the national security of the United States, in which case the head of such element shall provide to the congressional intelligence committees a written certification describing—
the reasons extended retention is necessary to protect the national security of the United States;
Section was enacted as part of the Intelligence Authorization Act for Fiscal Year 2015, and not as part of the Foreign Intelligence Surveillance Act of 1978 which comprises this chapter.