Most information concerning DEVGRU is designated as classified, and details of its activities are not usually commented on by either the United States Department of Defense or the White House.

[7] Despite the official name changes and increase in size, "SEAL Team Six" remains the unit's widely recognized moniker.

DEVGRU (along with its Army and Air Force counterparts, Delta Force, Intelligence Support Activity, the 75th Ranger Regiment's Regimental Reconnaissance Company and 24th Special Tactics Squadron), are the U.S. military's primary Tier 1 special mission units tasked with performing the most complex, classified, and dangerous missions directed by, until 2002, the National Command Authority, and since then, directly from the president or the secretary of defense.

[11][12][13] During the Iran hostage crisis in 1979, Richard Marcinko was one of two U.S. Navy representatives for a Joint Chiefs of Staff task force known as the TAT (Terrorist Action Team).

In the wake of the disaster at the Desert One base in Iran, the Navy saw the need for a full-time counter-terrorist unit and tasked Marcinko with its design and development.

SEAL Team Six was formally commissioned in November 1980, and an intense, progressive work-up training program made the unit mission-ready six months later.

[16] In 1984, Marcinko and a dozen members of SEAL Team Six would go on to form "Red Cell" (also known as OP-06D), a special unit designed to test the security of American military installations.

A new unit named the "Naval Special Warfare Development Group" was formed, essentially as SEAL Team Six's successor.

In 2010, during the attempted rescue of British aid worker Linda Norgrove from Taliban kidnappers in Afghanistan, she died as a result of injuries sustained from a SEAL's errant hand grenade.

In 2017, Army Special Forces Staff Sergeant Logan Melgar died from trauma received during an apparent on-base hazing incident in Mali that resulted in the criminal prosecutions of two DEVGRU members and two Marine Raiders.

Following a two-year investigation by The Intercept, a report was released in 2017, accusing SEAL Team Six and its commanding officers of abuses, crimes and coverups.

The requirements to apply for DEVGRU states that applicants must be male, be 21 years old or older, have served at least 2 deployments on their previous assignments, and be eligible for Secret clearance.

[24] Like all special operations forces units that have an extremely intensive and high-risk training schedule, there can be serious injuries and deaths.

It is presumed that the unit's assessment process for potential new recruits is different from what a SEAL operator experienced in his previous career, and much of the training tests the candidate's mental capacity rather than his physical condition.

According to the Government Accountability Office report on special operations forces, in the fiscal year of 2014, DEVGRU had a total of 1,787 authorized positions, of which 1,342 are military and 445 are civilian.

[67] The combination of these units led ultimately to the killing of Al-Qaeda leader Osama bin Laden in Operation Neptune Spear.