If you didn't earn a score that was high enough to be accepted to your chosen branch of the military, or if you didn't earn a line score high enough to qualify for a desired career option, then you may retake the ASVAB. You must wait a full month before you can take the ASVAB a second time. If you wish to take the test a third time, you must wait another month from the date of your second attempt. After the third attempt, there is a waiting period of 6 months before you can take the test again.
The Armed Forces Qualification Test (AFQT) derives from the more comprehensive, 10-subtest Armed Services Vocational Aptitude Battery (ASVAB). Scores on the four ASVAB math and verbal subtests are used to calculate an AFQT score, which determines whether an individual is generally qualified to enlist. Performance on all 10 ASVAB subtests, meanwhile, ascertains an enlistee's qualifications for specialized work within the military and possible incentives for enlistment.
Each branch of the military sets an AFQT score requirement for applicants. The lowest qualifying score is 31, which is needed to join the Army. Higher scores are required for other branches of the military. For example, the Coast Guard only considers applicants with a score of 40 or more. Prospective recruits who have a GED rather than a high school diploma will, in most cases, need to score at least 50 on the AFQT.
In addition to the ASVAB's AFQT, each branch has military occupational specialty, or MOS, scores. Combinations of scores from the nine tests are used to determine qualification for a MOS. These combinations are called "aptitude area scores", "composite scores", or "line scores". Each of the five armed services has its own aptitude area scores and sets its own minimum composite scores for each MOS.
While considered part of the non-commissioned officer corps by law, senior non-commissioned officers (SNCOs) referred to as chief petty officers in the Navy and Coast Guard, or staff non-commissioned officers in the Marine Corps, perform duties more focused on leadership rather than technical expertise. Promotion to the SNCO ranks, E-7 through E-9 (E-6 through E-9 in the Marine Corps) is highly competitive. Personnel totals at the pay grades of E-8 and E-9 are limited by federal law to 2.5 percent and 1 percent of a service's enlisted force, respectively. SNCOs act as leaders of small units and as staff. Some SNCOs manage programs at headquarters level and a select few wield responsibility at the highest levels of the military structure. Most unit commanders have a SNCO as an enlisted advisor. All SNCOs are expected to mentor junior commissioned officers as well as the enlisted in their duty sections. The typical enlistee can expect to attain SNCO rank after 10 to 16 years of service.
In the 2000s, women can serve on U.S. combat ships, including in command roles. They are permitted to serve on submarines. Women can fly military aircraft and make up 2% of all pilots in the U.S. Military. In 2003, Major Kim Campbell was awarded the Distinguished Flying Cross for landing her combat damaged A-10 Thunderbolt II with no hydraulic control and only one functional engine after being struck by hostile fire over Baghdad.