Our sister site, Law StackExchange, has this same question: Is it truly illegal for the US army to hire someone with IQ less than 83?Is it truly illegal for the US army to hire someone with IQ less than 83?, with a high-quality accepted answer.
The answer is not a simple yes or no, but the claim is not too misleading:
the assertion that the law prohibits people with an IQ score of 83 or less from serving in the U.S. military is close to the truth, although the reality is somewhat more complicated.
The answer goes on to explain that there is an aptitude test that applicants are required to take:
Applicants are also required to take the Armed Services Vocational Aptitude Battery (ASVAB) from which the applicant receives an AFQT score is equal to the applicant's percentile ranking of the applicant's raw score on the test. An applicant's AFQT score is strongly correlated with a applicant's IQ score on a traditional IQ test.
However, they are easily compared:
It isn't unreasonable to estimate that an AFQT score of 10 corresponds to an IQ score of 83, although I haven't seen any source making that exact conversion. My best guess is that the minimum AFQT score of 10 corresponds to an IQ score of more than 83 but less than 92 on a Stanford-Binet scale.
It explains the cut-off may be adjusted by Congress from time-to-time.
