Borderline intellectual functioning is a cognitive impairment that applies to people who have lower than average intelligence but don't have what Social Security calls intellectual disorder—a severe intellectual disability, formerly known as mental retardation.
People with borderline intellectual functioning typically have difficulties with learning, reasoning, planning, abstract thinking, and judgment. Lower than average intellectual functioning can be caused by birth injury, infections, genetics, fetal alcohol syndrome, or environmental exposure to toxins such as lead.
Borderline intellectual functioning is diagnosed by IQ test scores that are between 71 and 84. People with scores that fall within that range may qualify for disability benefits under Social Security's "Blue Book" listing 12.11 for neurodevelopmental disorders.
In order to qualify for disability for borderline intellectual functioning under listing 12.11, you must provide medical evidence showing one or more of the following symptoms:
If you have borderline intellectual functioning, you would probably meet the first item above, "difficulties learning and using academic skills," but you need to document your limitations with objective data like school reports, work evaluations, and I.Q. test results showing an I.Q. of less than 85.
You'll also need to show that your symptoms cause you to have an "extreme" limitation in one, or a "marked" limitation in two, of the following areas:
Extreme limitations are more severe than "marked" (severe) limitations, and generally apply to people with an IQ of 70 or below—which isn't considered borderline intellectual functioning.
Many applicants can show that their borderline intellectual functioning causes a marked limitation in learning and understanding, but it can be harder to establish a marked limitation in a second area. You can help Social Security better understand how severe your limitations are if you can get your doctor to provide a medical source statement describing the ways that you meet the listing requirements.
If you don't meet the listing because you have only mild or moderate limitations in mental functioning, you can still win benefits by proving that your impairments make it impossible to find full-time work. Applicants with borderline intellectual functioning in combination with other mental or physical impairments have a better chance of showing they can't work than applicants who have borderline intellectual functioning as their only impairment.
If a disability applicant doesn't meet the requirements of a listing, Social Security will review their medical record for evidence of mental limitations to assess their "mental residual functional capacity" (RFC). A mental RFC is a set of restrictions on the ability to work in the following areas:
Applicants who have additional physical restrictions in addition to borderline intellectual functioning will have those restrictions reflected in a physical RFC.
A physical RFC will contain strength-related restrictions on the types of jobs you can do using what's called exertional levels.
Your exertional level is the bulk of your physical RFC—and a key factor in determining whether you're awarded disability under the medical-vocational grid rules. But most people who are found disabled are able to rule out all work due to a combination of their exertional level and other, non-strength-related restrictions called non-exertional limitations. If your exertional, non-exertional, and mental limitations keep you from performing your past work or any other jobs, Social Security will find that you're disabled.
Social Security will look at school records, testimony from teachers or supervisors, and doctors' notes when evaluating disability for borderline intellectual functioning. For example, evidence of difficulties with concentration may be found in work evaluations that show frequent errors.
In addition, applicants should submit their IQ test scores to Social Security, making sure to include information about the standard deviation of the IQ test that was used. The standard deviation could indicate that test scores tend to be high and may not fully reflect the applicant's disability.
If you need help determining which evidence you should submit with your (or your child's) application for disability, consider hiring an experienced disability attorney. A lawyer can handle communications with the Social Security Administration, represent you at a hearing in front of an administrative law judge, and increase your chances of getting benefits.
Updated July 21, 2023