President Obama is preparing to offer legislation to make good on his promise to reform the National Security Agency's bulk collection of U.S. phone records, also known as metadata. Whether or not that legislation passes through Congress is yet to be seen.

After ex-NSA contractor Edward Snowden leaked top-secret documents that led to an avalanche of revelations about the NSA's digital surveillance activities and created an outcry from citizens, watchdog groups, and tech industry leaders, President Obama outlined proposals in January to reform the spy agency's collection of U.S. citizens' metadata.

Now, the Obama administration has said it is about to introduce legislation in Congress to affect some of his changes. The legislation, which has yet to be unveiled, will reportedly change the way the NSA obtains phone records, while keeping preserving the agency's ability to make connections in the metadata between targets of interest and potential confederates.

Currently, the NSA itself holds on to phone data for five years. Under the new legislation, a new type of surveillance system would require phone companies to keep records and quickly make the data available to the NSA in an easy-to-use format, according to the New York Times. Currently phone companies hold on to customer calling records for 18 months, so the data backlogs available to the NSA under the new system would be significantly less than the incumbent system.

Also under the new system, the NSA could only obtain specific metadata records with the permission of a judge, though once an order is placed with the company, any new calls to or from the target would be available on a continuing basis.

However, there are a few NSA reforms that deal with the storage of bulk phone metadata in different ways. Along with Obama's expected proposal for phone companies being responsible for holding the metadata, another proposal from an independent review panel suggests a non-government third party to hold the records. Telecommunications companies are likely to back the "third party" option, as, according to the Associated Press, phone company executives (and others) have come out with strong opposition to keeping custody of the metadata -- due to customer lawsuit liabilities, the cost of changing procedures and meeting NSA demands, and new privacy concerns.

In addition to proposed reforms, the White House's proposal will include a provision to extend the current NSA bulk metadata collection program by at least another 90 days, according to the Times' anonymous sources in the administration. This is being described as a stopgap of sorts, because any congressional action is unlikely to be swift, especially on reform measures that have created differences of opinion, even within political parties. In addition, there are already several competing bills in Congress to reform the NSA's metadata program.

According to the AP, the NSA bulk metadata collection program is set to expire next summer, so if Congress doesn't act before then to reform or extend it, the program will come to a complete stop.