The top-secret five-page memorandum of understanding stresses Americans' constitutional rights to privacy and Israel's need to respect these rights, but says nothing in the agreement is legally binding, British newspaper The Guardian reported, citing the document, leaked by former NSA contractor Edward Snowden.
The document points out the Israeli Sigint National Unit, Israel's NSA counterpart, will receive "unevaluated" raw information, including "transcripts, gists, facsimiles, telex, voice and digital network intelligence metadata and content."
Digital network intelligence is the NSA term for data collected from the Internet.
The document says if the Israeli signals intelligence unit finds confidential information about Americans, it should work with NSA liaison officers to black out the people's names and other private information -- a process the intelligence community calls "minimization."
The document says Israel may keep "any files containing the identities of U.S. persons" for up to a year but must destroy any U.S. government communications "upon recognition."
The agreement -- which can be found at tinyurl.com/UPI-NSA-Israel -- also places no limits on how Israel may use the information.
Israel had no immediate comment.
An NSA spokesperson did not deny personal data about Americans were included in the raw information given to Israel, but said in a statement the shared information complied "with all applicable rules, including the rules to protect U.S. person information."
The NSA declined to answer specific questions from The Guardian about the agreement, including how many times Americans' data were found in the raw intelligence and whether the program was authorized by the Foreign Intelligence Surveillance Court.
The court issues warrants and sets rules for collecting foreign intelligence inside the United States.
The Obama administration has insisted rigorous safeguards protect the privacy of U.S. citizens caught in the NSA dragnet.