Brees has been involved in lengthy contract talks with the Saints and, without the tag, could have negotiated with other teams as a free agent. Team spokesman Greg Bensel said Saturday that the Saints were officially notifying the NFL of the designation.
The New Orleans Times-Picayune and ESPN.com previously reported that Brees would get the tag.
In January, Brees said he would be "beyond stunned" if he and the Saints are unable to agree on a contract extension during this offseason.
In 2011, Brees set NFL records with 468 completions, 5,476 yards passing and a completion percentage of 71.2. His prolific passing numbers helped the Saints set a new NFL high for total offensive yards in a season with 7,474.
He has been with the Saints for six seasons, leading them to a win in the 2010 Super Bowl.