A standing-room-only crowd of 400 uniformed and civilian employees and their supporters filled a Pentagon auditorium Tuesday as the military celebrated gay pride month for the first time.

The repeal of the “don't ask, don’t tell” policy, which caused gay service members to be fired if they disclosed their sexual orientation, has gone “better than we anticipated,” Jeh Johnson, the Pentagon’s general counsel, told the crowd.

“As recently as three years ago, it would have been hard for many of us — including me — to believe that in the year 2012, a gay man or woman in the armed forces could be honest about their sexual orientation, that ... the don’t ask, don’t tell law ... would be gone from the books, and that the process of repeal would have gone even smoother and less eventful [than Pentagon leaders] predicted,” Johnson said. With some small exceptions, allowing gay service members to serve openly has not affected morale or readiness, he said.

The next step toward full equality for gay service members is benefits for troops in same-sex marriages and for same-sex domestic partners, who are limited by federal law from receiving health and other benefits.

Johnson said the Pentagon is reviewing how and whether to extend a myriad of benefits to them by working around the Defense of Marriage Act, which prohibits same-sex marriages.

An estimated 66,000 gay and lesbian troops are on active duty, advocates say. The prohibition on serving openly forced more than 13,000 from the armed forces since the “don’t ask, don’t tell” policy was adopted during the Clinton administration.

Tuesday’s hour-long ceremony included testimonials from three openly gay civilians and service members with varied and successful military careers: Gordon O. Tanner, principal deputy general counsel of the Air Force; Capt. M. Matthew Phelps, who serves at the Marine Corps Recruit Depot in San Diego; and Brenda S. “Sue” Fulton, a West Point graduate on the military academy’s board of visitors and founding board member of OutServe, a formerly clandestine professional association for gay service members.

They all told personal stories of being burdened for years in the closet at work.

“We need to be as visible as we can be,” Tanner advised the crowd. “We have straight allies who support us. Help us be the bridge to our straight allies.” He acknowledged his husband of two years, Robert, in the audience.

Fulton recalled how she had to hide her sexual orientation when she served in the Army. “The Army redacted our lives,” she said. “We can have those lives now and still serve the country we love.”

Perhaps the most moving account came from Phelps, who enlisted in the Marines in 2002 after the terror attacks of Sept. 11, 2001. He had come out to his parents at 18, but as a new Marine at 25, he lied to his recruiter and said he was straight. During a tour of Iraq in 2007, he felt distant from his unit when his fellow service members socialized, and realized how his lie was having the opposite effect it was supposed to have: The sense of cohesion the military prizes so highly was not there for him.

On the day last September when the repeal finally took effect, Phelps said he went to work and waited for the phone to ring. Or for a slew of e-mails to pop into his inbox. “I braced myself on the desk waiting for everyone to ask me if I was gay,” he recalled. The phone didn’t ring. ... His work life was just like anyone else’s. He felt like he was going to work for the first time

Then, last week, he was invited to a White House reception for gay pride month. He went from being a gay man afraid he would be discharged to drinking champagne with his commander in chief, “on cocktail napkins with the presidential seal on them,” he said.