The decision is the result of a broad investigation of the security of Navy buildings outside major bases, such as reserve centers and recruiting stations that are often open to the public and, prior to the shooting, did not have armed guards.
Fleet Forces officials said the Navy is in the final stages of writing the policy.
"We are in the final stages of preparations for implementation" of the policy, said Cmdr. Dave Aliberti, policy branch head for Fleet Forces Command's anti-terrorism, force protection directorate. "It is going to be a system put in place to arm personnel that are there for deterrent value and to provide protection."
The guards will be trained, uniformed sailors, but are strictly for security, said one official on background. They will not be authorized to respond to crime in the area of the stations, which is prohibited by law.
In the immediate wake of the Chattanooga shootings, Fleet Forces head Adm. Phil Davidson ordered armed guards to begin patrolling all 71 of the Navy's reserve centers, called Navy Operational Support Centers.
Those sailors, mostly activated reserve masters-at-arms, were in place within weeks of the attacks.
On the morning of July 16, 2015, a 24-year-old American named Mohammad Abdulazeez, who went to high school in the area, drove a rented car to a recruiting station in Chattanooga and pumped dozens of rounds into the windows and doors with an assault rifle. The rounds injured one of the Marine recruiters.
Then the shooter made a seven-minute drive across town to the NOSC, crashed the gate and murdered five service members inside.
Killed in the attack were Marine Gunnery Sgt. Thomas Sullivan, Lance Cpl. Squire K. Wells, Staff Sgt. David Wyatt and Sgt. Carson Holmquist. Navy Logistics Specialist 2nd Class Randall Smith died July 18 from wounds sustained during the shooting.
The shooting prompted a thorough review of the security at the off-base buildings, which can be stand-alone structures like the Navy Operational Support Center Chattanooga, or in shopping and strip malls, which are what security experts call "soft targets" for terrorists.
The Fleet Forces investigation was aimed at hardening those targets in the future.
"Our efforts since the shooting have been focused on enhancing force protection for off-installation activities, as well as the entire force," Aliberti said.
"Our actions, informed by the investigation, also address key areas directed by the secretary of defense's memoranda of July 29 and Oct. 2, 2015, and include arming personnel, force protection enhancements for off-installation facilities, active shooter training, physical improvements and mass warning notification systems that will enhance security and force protection and improve our ability to protect our personnel."
Some lawmakers called for service members, especially recruiters, to be allowed to carry their personal firearms to work so they could respond to an attack in progress. Aliberti said that was looked at in detail but it is not being considered.
"Because of the nature of their mission it's something less than ideal to have every recruiter armed when their mission is engagement with the public," he said. "While that would be one extreme, it's not something that is being considered seriously at this time."
Navy leaders have also been less than enthusiastic about allowing sailors to bring their guns on bases. In an April interview with Navy Times and Defense News, the Navy's top officer said the idea was on the table but that he was concerned about a situation where more guns are present during a shooting creating confusion for law enforcement.
"It is on the table for sure," said Adm. John Richardson, chief of naval operations. "You know, I get questions: 'What about concealed carry if I've got a license to carry a weapon what about that?'
"That raises a lot of concerns just in terms of controlling a certain area when it breaks out. Again, a thoughtful approach to this [is best], we don't want to restrict our solution set upfront."
In addition to the presence of more armed personnel at the recruiting stations and at the NOSCs, sailors and officers will also be given high-level anti-terrorism training specific to off-base facilities, which did not exist before the shootings, Aliberti said.
Militarywide, the Army Corps of Engineers is upgrading recruiting stations' security with visual identification features, as well as better access control mechanisms and ballistic shields, he said. The Army Corps is also making alterations to buildings that make them more secure, he said.
Another lesson that came out of Chattanooga was the absence of a good alert system.
Seven minutes elapsed between the shooter's first attack on the recruiting center and his last attack on the NOSC across town. In the intervening seven minutes, the service members at the NOSC had no idea that a military facility across town had been attacked. That's one thing the military is determined to change, Aliberti said.
Fleet Forces led the Navy security review of all its facilities not located on a military base, which often do not have controlled entries.
As a result of an October memo from Defense Secretary Ash Carter, the Defense Department formed a working group that is developing and implementing a militarywide alert system that will, in the event of an attack, alert service members within a certain radius that an attack has taken place, Aliberti said.
But Navy recruiting stations and NOSCs have already improvised new systems, Aliberti said.
"There was an immediate recognition that we need to improve our mass warning and notification capabilities at both the NOSCs and recruiting stations," Aliberti said. "All the recruiters are issued iPhone 6s and there is an app for that, believe it or not. All the phones are now enabled with a one-touch alert to all recruiters in a defined radius. They immediately implemented that for the recruiters.
"We used different methods for the NOSCs which were at different levels capabilities-wise."
David B. Larter was the naval warfare reporter for Defense News.