Versions of this story were co-published with NPR and Stars and Stripes. For more coverage, listen to Morning Edition.

One afternoon this fall, Bobby McKinney hunched over a coffee table with a clear glass surface. A lamp with a bare light bulb illuminated it from below. Pencil in hand, the former Marine traced the pattern for a tattoo across delicate paper, a swirling, intricate design reminiscent of a Celtic cross.

McKinney's small apartment faded from his thoughts: The closet filled with shirts and pairs of jeans, hung three inches apart, all facing exactly the same direction, the way the Marines had taught him. The box packed with a dozen brown plastic medicine bottles. The worn couch that he slept on instead of the bed. The eraser board on his refrigerator where he had scrawled "A coward dies a 1,000 deaths. A warrior dies one."

Suddenly, a nurse's aide knocked on the door. Had he checked the oven? McKinney leapt up and ran to the kitchen, pulling out a tin of brownies on the point of burning.

"I guess I was just very focused on the tattoo design," he told a counselor later, pushing a camouflage baseball cap back on his head. "I set the alarm. I guess I just didn't hear it."

"Try to work on one thing at a time," she told him. "Multitasking is just asking the brain to do two or three things not too well."

McKinney, 29, nodded in agreement. It seemed so obvious once she said it. But his mind -- the mind that once helped sniper teams in Iraq, that navigated battlefield maps and complex rules of enemy engagement -- had just not come up with the idea to do one task instead of many. "When you think about it, it kinda makes sense. But I wouldn't think about it on my own," he said.

McKinney is an Iraq war veteran who suffered multiple concussions, also known as mild traumatic brain injuries. Bomb blasts jarred his brain, leaving him with no outside scars, but with nagging mental problems. His short-term memory is bad. He moves slowly through ordinary chores. He gets disoriented easily, and can't find his way to the home that he has lived in for months without the aid of a GPS.

A farm boy fond of the Georgia Bulldogs and chewing tobacco, McKinney has pinned his hopes for recovery on cognitive rehabilitation therapy, a subtle and complex treatment for a subtle and complex injury. Doctors and studies have shown that the therapy helps soldiers. But the Pentagon's primary health plan for soldiers and seriously wounded veterans, called Tricare, will not cover the treatment, saying it is still unproven.

To see what cognitive therapy looked like, ProPublica and NPR spent several days with McKinney and fellow soldiers and veterans at Project Share, a charity to help brain-damaged soldiers. The program is based out of the Shepherd Center for Brain and Spinal Cord Injury in Atlanta, a nationally recognized hospital for head injuries.

Former Home Depot magnate and philanthropist Bernie Marcus founded Project Share in January 2008 to fill the gaps left by Tricare and military and veterans hospitals, which often lack the expertise and staffing to provide a full-scale program of cognitive rehabilitation therapy.

Cognitive rehabilitation is "very time consuming. It's not an easy deal," said Marcus. "Isn't this worthwhile? Isn't this something we should all be concerned about? Whatever it takes is what we should give them."

The visit revealed no flashy techniques, no cutting-edge medical devices. Instead, the men spent their entire days with therapists who focused on improving their memory, speech, balance and psychological health.

Soldiers got individualized treatment plans from a team of therapists who administered an intensive, two-week long evaluation to pin down their cognitive needs.

Therapists from different fields closely coordinated. A behavioral therapist provided counseling, since nearly all of the soldiers have post-traumatic stress disorder, a psychological injury which frequently accompanies traumatic brain injuries.

A speech therapist taught basic organizational techniques to overcome memory problems: How to make lists, how to pay bills, how to organize paperwork. A physical therapist helped them manage pain and relearn balance, which is often thrown off after a blast injury.

In the evenings, the men lived in apartments provided by the center. They did daily field trips, doing errands that are commonplace for most, but difficult for those with cognitive problems. They shopped at a grocery store. They cooked dinner. They helped assemble wheelchairs for the needy. They went to a horse park, where they combed, fed and rode horses.

At each step, a therapist helped them prepare for the job at hand. They suggested making to-do lists; using an iPod to keep track of medications; storing medical and military records into clearly labeled file folders.

Soldiers get a blue rubber bracelet with the initials SWAPS. The letters are supposed to remind them of a course of action should they become frustrated or mentally overloaded. The letters are an acronym: Stop; What's the problem?; Alternatives and options; Pick a plan; Satisfied?

The men stay for two and three months at a time. Afterwards, a Project Share worker follows them for up to a year to make sure that they are using the techniques they have learned to cope with life in the real world.

"It's very cozy and cocoon-like and warm and fuzzy here," said Tina Raziano, who visits soldiers and veterans at their homes and military bases to make sure they are adjusting. "When they leave here, they go through major, major changes. You really have to adjust to a new normal."

Cognitive therapy is not a silver bullet, nor is it a one-time treatment, or a rigid, well defined program. Instead, therapists here say, it employs a variety of techniques designed to do the hard work of retraining each soldier's brain to compensate for the things it can no longer do.

"We all see that they start out unable to do basic tasks," said Bonnie Schaude, a speech pathologist who coordinates many of the treatments. "People are leaving here, and they can function independently."

The visit made just as clear, however, the difficulty of implementing such an intensive, long-term plan for the military or Department of Veterans Affairs. Official Pentagon figures show that 188,000 soldiers have suffered some kind of brain injury since 2000. The number includes blast wounds, but also head trauma sustained in vehicle crashes, training accidents and household falls. Previous NPR and ProPublica stories have shown that the number likely falls short of the full tally by tens of thousands of soldiers.

The vast majority of head injuries are concussions, from which most soldiers recover quickly. The only treatment needed is bed rest and perhaps pain medication for headaches. But providing the kind of care available at Project Share to even the small percentage of brain-damaged soldiers who need it would require a tremendous commitment of time and money from military and veteran medical systems.

Project Share provides more than 30 hours of rehabilitation a week for several months at a time, and a year of follow up. In contrast, most VA and military systems can provide only a few hours of therapy a week. All Project Share's services are in one building, across the street from the Shepherd Center and its scores of cognitive experts. Military and VA facilities can spend months recruiting a single neurologist at a base for 30,000 soldiers.

The Pentagon's medical budget is $50 billion a year, expected to skyrocket to $65 billion by 2015. The system already cannot fill the slots available for psychologists, counselors and neuropsychologists, who can make better money in the private sector. The VA also has to care for an enormous population of aging veterans, whose geriatric needs are far different than the needs of injured Iraq and Afghanistan war veterans.

Project Share even has the resources to fly in family members and spouses on private planes, the costs and time donated by volunteers. A pilot flew Tiffany Dantzler, 22, from South Carolina to Georgia one recent day to visit her boyfriend, Ashley Craft, so the two could receive joint counseling on what to expect from brain damage recovery.

Craft, 26, sustained burns and a brain injury in a 2006 roadside bomb explosion in Iraq. After the explosion, he could not remember his own name. A specialist in the Marine Corps, he was medically retired in August 2007. He suffered from post-traumatic stress. He got angry quickly. A mechanic who worked on military vehicles, he could no longer tune up a car back home.

Craft got treatment at VA hospitals in Richmond and Columbia, S.C., near his home. But each time he left the programs, he felt lost and abandoned, he said.

His captain in the Marine Corps heard about Project Share, and got him admitted. Craft now hopes that the intensive rehabilitation will help him return to a normal life. At a recent session on anger management, he tried to take notes on a handheld memory device, painfully typing in one pointer after another.

"You're not the way you used to be. And it's really tough to grasp that concept," he said. "I used to think I was pretty good, and now I have to use a lot of adaptive equipment to remind myself, or to even be half as good as I used to be. That's what I got to do. That's my life now."

Shy and hesitant when he talks, a man who has seen his expectations dashed more than once, Craft said he is more hopeful, now. Project Share provides him far more intensive care than he was able to receive in the military, he said. His girlfriend has already noticed a difference.

"He seems more confident about what he says. His memory seems a little bit better," Dantzler said. "He seems more alive."

Marcus, the philanthropist who supports the program, said the expense and effort are worth it. In July 2008, he visited officials at the Army Surgeon General's office to pitch cooperation between Project Share and the military. He got a tepid response, according to Marcus and several others present at the meeting. The military said it wanted to focus more on improving its own treatment centers.

Marcus left frustrated. He had visions of an alliance between the military and a nationwide network of civilian treatment programs. Instead, Project Share has treated about 70 soldiers since it began two and half years ago. Since there's no formal relationship with the military, soldiers generally get referred by word of mouth. The military sent one therapist to receive training.

"That's where the problem is, trying to keep it internal when in fact you don't have the resources," Marcus said. "If you can't do it yourself, outsource what you can't do. That's the name of the game." Military and VA officials "all say things that you want them to say, but the bottom line is, it's not happening."

As he talked, Marcus grew agitated.

"I don't feel that Washington has paid attention to this thing. I don't think that Washington has done enough on this. I blame the president, I blame the Congress, for not giving these kids the opportunity to go on with a fruitful life after they have devoted their service to this country and put their lives on the line," Marcus said.

"It just doesn't make sense to me. It frustrates me. And it angers me. Kids are wandering around the streets today that will become tomorrow's criminals that were yesterday's heroes. How pathetic is that?

"We owe these kids a hell of a lot more."

Cpl. Brendan Jannesen, 23, a special forces soldier in the 75th Ranger Regiment, was patrolling at night in Afghanistan in August 2010 carrying heavy gear when he slipped off a trail, falling down a steep slope.

Tall, thin and fit, Jannesen had been a forward observer, trained to coordinate airplane and artillery strikes with soldiers on the ground attacking Taliban fighters. A math whiz, he could simultaneously juggle people screaming in both ears as he figured out the angle for incoming mortar strikes in the middle of battle.

When he awoke from his fall, however, Jannesen struggled to do simple arithmetic. He had to use his fingers to add. Jannesen's sergeant sent him to Project Share, hoping that its intensive approach would help.

Sitting in a common room with a poker table, Jannesen became passionate as he described how much he wants to return to duty, how much he has improved so far.

"I could do degrees, azimuth, you have to calculate the time of flight, the number of rounds, how fast your target is moving to try to get a direct hit on target. It was very, very heavy on cognitive demands," he said. "Now, I get worn out trying to write out a to-do list. It's very, very frustrating and very difficult to handle. You want to do stuff, but you can't do it."

About half the patients at Project Share are veterans, medically retired from the service and hoping to return to civilian life. The others are active duty soldiers who aim to return to their units. They are mostly Marines and special operations soldiers whose superiors have heard about the program through the close-knit communities that characterize those two forces.

Therapists say that nearly all of their patients are motivated: To get better, to navigate their lives, to recover from a baffling condition that has fundamentally changed the way they think and act in ways all but invisible to the outside world.

Mild traumatic brain injury "can be a blessing and a curse," said Irene Spychalla, case manager for Project Share. "These guys look completely healthy. They're walking, they're talking. You don't realize they're struggling with their daily lives."

A Marine since 1998, Sgt. Orville Wempner, Jr. was sitting on a tarmac in Iraq in 2004 when a mortar landed nearby. He remained conscious but was left with pounding headaches for weeks afterwards.

A water purification specialist, Wempner grew perplexed after he started having trouble operating the enormous, 5-ton pumping machine whose internal workings he had mastered long before the blast. He began to carry around a small green notebook to write down all his tasks. One day, he was alone taking care of his 6-year-old daughter and he simply forgot to feed her dinner.

Wempner, a Minnesotan known to his friends as Junior, knew that something was wrong. His brain, he said, was like a car engine with miswired spark plugs.

Wempner said his brain "feels like it's misfiring. There are days that I'm sitting there and everything is clear and then there's more days when I'm confused, not knowing what I'm supposed to be doing, where I need to go."

Wempner entered the Project Share program in September. Therapists worked hard on helping him learn to organize and prioritize. They retaught him to make lists. They trained him how to keep a calendar with all his appointments written down.

Basic stuff. But for Wempner, they were the tools to getting his brain working right again.

"It does sound pretty simple and down to earth," he said. "But when you're not thinking clear ... simple things like that don't really work."

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