What Is SSI and How Is It Different From SSDI?

When people talk about disability benefits in the United States, two acronyms come up over and over: SSI and SSDI. They sound similar, and both programs involve cash benefits for people who meet certain disability or income criteria. But after that, the overlap ends. These programs are fundamentally different—different rules, different eligibility paths, different funding sources, and different long-term implications.

If you’ve been trying to understand which program fits your situation—or whether someone can receive both—this breakdown will help you get clarity without the jargon.

What Is SSI?

Supplemental Security Income (SSI) is a needs-based program. It’s designed for people who have limited income and limited resources and who are either:

1. Age 65 or older,

2. Blind, or

3. Disabled according to the Social Security Administration’s (SSA) definition.

Key traits of SSI

• Not based on work history. You don’t need to have paid into Social Security to qualify.

• Funded by general federal tax revenue, not payroll taxes.

• Provides monthly cash payments, but the amount is relatively modest.

• Has strict income and asset limits.

• Often includes automatic access to Medicaid in most states.

Who SSI is for

SSI is meant as a safety net. It supports people who can’t rely on their work history or savings to meet basic needs. This includes many individuals with lifelong disabilities, older adults with little to no retirement income, and people who have very limited financial support.

Income and asset rules

SSI has some of the strictest financial rules of any federal program.

• Assets are capped at $2,000 for individuals and $3,000 for couples.
  Certain assets, like a primary home or one vehicle, don’t count.

• Income limits vary, because SSI reduces your benefit when you earn income, but the idea is that any income you do have must be very low.

If someone wins SSI approval but their financial situation improves significantly afterward, their SSI benefits can be reduced or even terminated.

What Is SSDI?

Social Security Disability Insurance (SSDI) is a work-based program. You qualify because you’ve worked long enough and paid Social Security payroll taxes (FICA). In other words, it’s an insurance policy you pay into while you work.

Key traits of SSDI

• Based on work credits, not financial need.

• Funded by Social Security payroll taxes.

• Provides monthly benefits that typically reflect your past earnings.

• Has no asset limit and no household income limit.

• Leads to Medicare eligibility after two years of receiving benefits (in most cases).

Who SSDI is for

SSDI is intended for people who have a meaningful work history but can no longer work due to disability. This includes individuals who worked for years before a chronic condition, accident, or severe illness made continuing employment impossible.

Work credits: the gatekeeper to SSDI

To qualify for SSDI, you need:

• A certain number of total work credits (based on lifetime work)

• A certain number of recent work credits (usually within the last five or ten years)

• A disability that meets SSA’s medical criteria and prevents substantial work

Because SSDI eligibility depends heavily on past earnings and when they occurred, two people with the same disability may have different eligibility outcomes.

How SSI and SSDI Compare

Here’s a practical side-by-side comparison:

What Disabilities Qualify for SSI or SSDI?

Although SSI and SSDI differ in eligibility criteria, in terms of disability, they use the same definition, which requires:

• A medically determinable physical or mental impairment

• Expected to last at least one year or result in death

• Prevents substantial gainful activity (SGA)

This shared medical standard explains why the approval process for both programs can be rigorous.

How Much Do SSI and SSDI Pay?

SSI Payments

SSI amounts are fairly consistent nationwide, with small variations in states that supplement the federal payment.

• SSI benefits are intentionally modest, meant to cover essentials.

• Income you earn or receive may reduce the monthly benefit.

SSDI Payments

SSDI benefits depend on your average lifetime earnings. Those who paid into the system longer and at higher wages receive more.

• There is no reduction based on your assets.

• Family members may qualify for additional benefits.

In general, SSDI benefits are significantly higher than SSI benefits.

Can Someone Get Both SSI and SSDI?

Yes, this is called concurrent benefits.

Someone might qualify for SSDI based on a limited work history but receive a low monthly SSDI amount—often due to low wages, part-time work, or few work years. If that SSDI benefit is low enough, the person may also receive SSI to bring their total income closer to the SSI maximum.

To qualify for both, the person must still meet SSI’s income and asset rules.

How the Application Processes Differ

Although both programs share the same disability determination system, the financial screens differ greatly.

Applying for SSI

You must demonstrate:

• Very limited income

• Very limited assets

• A qualifying disability (unless you’re 65+)

Financial documentation—bank statements, living arrangements, and income details—is central to approval.

Applying for SSDI

You must demonstrate:

• Enough work credits

• A disability severe enough to prevent substantial work

Your earnings history is as important as medical documentation. Many applicants who meet medical criteria still get denied because they lack sufficient work credits.

What Happens After Approval?

SSI Recipients

• Usually get Medicaid right away.

• Must report income changes quickly.

• May see benefits change if their living situation changes (e.g., someone else paying rent).

SSDI Recipients

• Receive Medicare after a two-year waiting period (with some exceptions).

• Can attempt part-time work through “trial work period” programs without immediate risk of losing benefits.

• Don’t have to worry about assets like savings accounts or property.

Common Misconceptions

“SSI and SSDI are basically the same.”

Not even close. One is financial-need based; the other is earned insurance.

“You must be low income to get SSDI.”

False. SSDI has no asset limit and no requirement to be low income.

“You can’t work at all if you get disability benefits.”

Partially true, but more nuanced.
Both programs allow limited work, but the rules differ, and SSDI offers more flexibility. Working too much can disqualify you from either program, but the level of allowable income varies.

“Disability approval means permanent benefits.”

Not necessarily. The SSA periodically reviews cases for medical improvement. SSI recipients also face ongoing financial reviews.

Why Understanding the Difference Matters

These programs support millions of Americans, but people often apply for the wrong program or misunderstand what they’re applying for. Knowing the distinction helps you:

• Choose the correct program from the start

• Gather the right documents

• Set the right expectations about payments and health coverage

• Understand how work or savings might affect your benefits

• Avoid unintended loss of benefits

Whether you’re applying for yourself or helping someone else, clarity upfront prevents frustration later.

Conclusion

SSI and SSDI may share a disability standard, but the similarities stop there. SSI is a safety-net program for people with very limited income and resources, regardless of work history. SSDI is an insurance benefit earned through years of employment and payroll taxes. The programs serve different groups, pay different amounts, and have different rules for work, assets, and health coverage.

If you or someone you know is considering applying, the best next step is to evaluate work history, financial situation, and current medical condition. That gives a clean starting point for determining which program—or whether both—might be the right fit.