Most people focus on the retirement benefits that Social Security pays. That makes sense, since out of the nearly 62 million people receiving benefits, three-quarters receive retirement benefits. Yet Social Security also provides the valuable service of providing replacement income in the event that you become disabled.

More than 10 million people get Social Security disability benefits, and it's useful to have an idea upfront about how much you'd receive if you became disabled. Below, we'll look more closely at how the Social Security Administration calculates disability benefits and what amounts you and your family members might be entitled to receive.

Two Social Security cards overlappiong a $100 bill.

Image source: Getty Images.

Can I get disability benefits under Social Security?

To get benefits, you need to meet a couple of work tests that require you to have had a job in which you paid Social Security payroll taxes. First, you need to have worked recently, with those younger than 24 having worked at least one and a half years out of the past three, those between 24 and 30 having worked half of the period since turning 21, and those 31 or older having worked five years out of the past 10.

Second, you also need enough total work during your career. Through age 42, you'll have enough total work if you meet the recent work requirement, with 42-year-olds needing five years of total employment. After that, though, the requirement goes up by half a year for every two additional years of age, topping out at 9.5 years for those age 60 or older.

How are my benefits calculated?

The process for calculating disability benefits is very similar to that for retirement benefits. The SSA looks at your work history and determines your average indexed monthly earnings. Then, it runs that number through a formula that produces a primary insurance benefit. To determine the primary insurance benefit in 2018, you'd take your average indexed monthly earnings and run it through three income ranges as follows:

  • Take 90% of the first $895.
  • Add 32% of any amount between $895 and $5,397.
  • Add 15% of any amount over $5,397.

So for example, if your average earnings was $3,000, you'd take 90% of $895 and then add in 32% of the remaining $2,105. So $805.50 plus $673.60 equals $1,479.10, so that's what your primary insurance amount would be, and that typically matches up to what you'll receive for your own disability benefit.

The difference between disability and retirement benefit calculations is in the length of work history that the SSA looks at. For retirees, the SSA takes your 35 top-earning years after adjusting for inflation. If you don't have a 35-year work history, then the missing years get filled in with zeros, bringing your average down.

For disability benefits, the SSA recognizes that if you're disabled early in your career, there's no way you'll have a 35-year work history. Therefore, it instead looks at a shorter period that varies according to age. Specifically, the SSA does the following calculation:

  • Take your current age and subtract 22. That gives you the number of full years in your potential career as an adult so far.
  • Take one-fifth of that number of years. Round it down to the nearest whole number, but if it's less than 2, use 2 instead. If it's more than 5, use 5 instead.
  • Subtract the second number from the first.

The result is the number of years of earnings included in your work history. For example, if you're 40, then 40 minus 22 is 18, and one-fifth of 18 is 3.6. Round that down to 3, and then 18 minus 3 is 15. So the disability calculation would be based on your 15 top years of earnings.

How much can my family get?

If you're eligible for disability benefits, then other family members can sometimes get benefits as well. Spouses can get benefits if they're 62 or older or if they're caring for your child who's disabled or under age 16 and receiving Social Security. Children can get benefits if they're under 18, a high-school student and no older than 19, or disabled.

Each family member can get up to 50% of the primary insurance amount for disability payments, but there's a family maximum amount that applies to all benefits on your work record. If the total payments on your account are greater than 150% to 180% of your primary insurance amount, then the SSA will limit the amounts paid to family members proportionately in order to stay under the family maximum.

Get the benefits you deserve

Disability can strike at any time, and the SSA estimates that about 1 in 4 workers who are currently 20 years old will become disabled at some point before reaching retirement age. By understanding the benefits that you're entitled to receive under Social Security disability, you'll be in a better position to prepare for what could happen.