Career enlisted members in the Air Force and Navy have drawn surprisingly near to their Army and Marine Corps peers in speed of advancement to higher rank and higher pay.

Enlisted promotion data gathered from the four services under the Defense Department show some remarkable changes from fiscal 2000 to 2005, the last year for which complete data is available. Average time in service for Air Force members, for example, as they advanced to pay grades E-6 or E-7 in 2005 was about four years faster than in 2000.

Sailors, too, are being promoted sooner. Average time in service at advancement to E-6 in 2005, was two years faster than in 2000. And sailors advancing to E-7 in 2005, on average, do so almost four years sooner than did shipmates five years earlier.

Soldiers and Marines haven't seen the same gain in advancements, yet they continue to make grade faster than sailors or airmen. Dramatic disparities in promotion pace, however, have narrowed noticeably.

(Data on enlisted advancement in the Coast Guard, an agency of the Department of Homeland Security, was not immediately available.)

The Air Force and Navy, which strive to keep large numbers of high-tech specialists for full careers, took several intentional actions, starting in 2000, to improve enlisted advancements and to shore up career retention. The Air Force's big move was to raise its proportion of career personnel.

For years it had capped total personnel serving in its top five enlisted grades, E-5 through E-9, to no more than 48 percent of its enlisted force. In 2000, the Air Force raised that cap to 50 percent and, in 2003, raised it again to 56 percent, said Chief Master Sgt. Trenda Voegtle, chief of Air Force enlisted promotions and evaluations policy. The impact was to expand advancement opportunities, most in grades E-5 through E-7.

The law limits the number of E-8s a service can have to 2 percent of its enlisted force and its number of E-9s to 1 percent. Otherwise, the services can control their own enlisted pay grades, limited only by a need to keep reasonable promotion opportunities at all grades and by the size of their personnel budgets. A more senior force costs more in pay, housing allowances, even in retirement trust fund contributions to cover future obligations. What a service hopes to buy with faster promotions is improved morale and career retention.

Because the Air Force grew the size of its career force grades of E-5 through E-7 by a full 8 percent points from 2000 through 2003, its enlisted promotion pace rose sharply. By fiscal 2005, members being advanced to E-5 were spending 20 fewer months as E-4s, on average, than had those members advanced to E-5 in 2000. By fiscal 2005, members being advanced to E-6, or technical sergeant, had seen their time as E-5s lowered by almost 27 months. The cumulative effect, on average, was to knock five and a half years off the pace at which Air Force personnel reached E-8.

Navy data show similar changes in the pace of enlisted promotions. A sailor being advanced to E-6, or petty officer first class, in fiscal 2000 served an average of six years, four months as an E-5. By fiscal 2005, that stint as E-5, or petty officer second class, had fallen to four years, six months.

Rear Adm. Michael LeFever said the thinking was: "How do we reward those performers who are really doing exceptional and not restrict them to time waivers or time in the Navy."