SSI vs. SSDI: What They Are, How They Work, and What Makes Them Different

If you’re trying to understand what SSI and SSDI are, you’re definitely not alone. These two disability programs are both run by the Social Security Administration (SSA), and they sound similar—but they work very differently.

This guide breaks down Supplemental Security Income (SSI) and Social Security Disability Insurance (SSDI) in clear, practical terms so you can see:

What each program is
Who might qualify
How benefits are calculated
Whether you can receive both
What to expect from the application process

What Is SSI?

Supplemental Security Income (SSI) is a need-based program for people with limited income and resources who are blind, disabled, or age 65 or older.

Key features of SSI

Based on financial need, not work history
Funded by general tax revenues, not Social Security payroll taxes
Available to adults and children
Can help with basic needs like food, clothing, and shelter

To qualify for SSI, you generally must:

Have limited income and limited resources (things you own)
Be age 65 or older, or
Be blind, or
Have a disability that meets Social Security’s definition (more on that below)
Be a U.S. citizen or meet specific lawful residency rules

How SSI benefits are calculated

SSI pays up to a federal base amount each month. That amount can be:

Reduced based on your countable income
Sometimes increased by your state (some states add a supplement)

Not all income counts against SSI. For example, small amounts of earned income, certain benefits, and some support from others may be partially or completely excluded.

Because it’s a means‑tested program, SSI also looks at your:

Resources (cash, bank accounts, some property)
Living situation (who you live with and who helps pay your expenses)

What Is SSDI?

Social Security Disability Insurance (SSDI) is an insurance-style program for people who have worked and paid into Social Security but can no longer work due to a qualifying disability.

Key features of SSDI

Based on your work history and Social Security taxes paid
Not limited by financial need (you can have savings and assets)
For adults with a disability (not for non‑disabled older adults)
May provide auxiliary benefits to some family members

To qualify for SSDI, you generally must:

Have a disability that meets Social Security’s definition
Have worked in jobs covered by Social Security
Have earned enough work credits for your age

What are work credits?

When you work and pay Social Security taxes, you earn work credits. You can earn up to four credits per year. The number needed for SSDI varies with age, but common patterns include:

Younger workers: may qualify with fewer credits
Workers over 30: usually need more recent and longer work history

The SSA looks at:

Recent work – Have you worked enough in the years before becoming disabled?
Duration of work – Have you worked long enough over your lifetime?

How SSDI benefits are calculated

SSDI benefits are based on your average lifetime earnings covered by Social Security, not your current income or resources.

Higher past earnings generally mean higher SSDI benefits
There is a maximum monthly amount the program pays
Some family members (such as minor children or certain spouses) may be eligible for dependents’ benefits based on your record

SSI vs. SSDI: Key Differences at a Glance

Here’s a simple comparison to see SSI and SSDI side by side:

Feature	SSI (Supplemental Security Income)	SSDI (Social Security Disability Insurance)
Main basis for eligibility	Financial need	Work history and disability
Funding source	General tax revenues	Social Security payroll taxes
Age groups covered	Disabled of any age, plus adults 65+ (no disability required at 65+)	Adults with qualifying disability
Resource limits	Yes – strict asset/resource limits	No general asset limit
Income limits	Yes – income affects eligibility and payment	No income limit from unearned income; work earnings may affect
Benefit amount based on	Federal base amount, adjusted for income and living situation	Your past covered earnings
Health coverage link	Often linked to Medicaid in many states	Often leads to Medicare after a waiting period
Possible to get without working?	Yes, if financial and disability/age rules are met	Generally no; requires enough work credits

What Do SSI and SSDI Have in Common?

Although SSI and SSDI are very different programs, they overlap in several ways.

Shared disability definition

For adults, both SSI and SSDI use the same definition of disability. In general, you must:

Have a medically determinable physical or mental impairment
That prevents you from doing substantial gainful activity (SGA) (essentially, significant work)
And is expected to last at least 12 months or result in death

They do not pay for partial or short‑term disability.

Same agency, similar process

Both programs:

Are run by the Social Security Administration (SSA)
Use a similar application and review process
May involve providing medical records, work history, and personal information
Involve a disability determination by a state agency that reviews medical evidence

Who Typically Qualifies for SSI?

People who often look into SSI include:

Adults with disabilities who have not worked much or at all
Children with serious physical or mental conditions in low-income households
Older adults (65+) with very limited income and resources

Financial requirements for SSI

To qualify, you generally must:

Have limited income: both earned income (from work) and unearned income (such as other benefits, support, or gifts) may count
Have limited resources: things like bank accounts, cash, or property other than a primary residence and one vehicle (within certain rules)

Because the rules can be detailed, many people find it helpful to:

List all sources of income
List all assets/resources
Review how SSI treats each type of income and resource

Who Typically Qualifies for SSDI?

People who often pursue SSDI include:

Workers who can no longer perform their job because of a serious health condition
Individuals with long work histories who have become disabled before retirement age
People who worked steadily but had to stop or greatly reduce work due to a disabling condition

Work and disability requirements for SSDI

To qualify for SSDI, it’s not enough just to have a health condition. The SSA will look at:

Your work history
- Did you work long enough in jobs that paid Social Security taxes?
- Did you work recently enough before becoming disabled?
Your ability to work now
- Can you do your past work given your limitations?
- Can you adjust to other types of work that exist in significant numbers?

If the SSA finds that your condition prevents both your past work and other suitable work, and you meet the work-credit requirements, you may qualify.

Can You Get Both SSI and SSDI at the Same Time?

Yes. Some people receive both SSDI and SSI. This is often called receiving “concurrent benefits.”

This can happen when:

You qualify for SSDI based on your work history, but the SSDI payment is relatively low, and
You also meet the financial need requirements for SSI

In this case:

SSDI pays based on your earnings record
SSI can supplement your income up to the SSI maximum for your situation

Health Insurance: SSI vs. SSDI

Another major difference between SSI and SSDI involves health coverage.

SSI and health coverage

Many states automatically connect SSI eligibility with Medicaid, which can help pay for:

Doctor visits
Hospital care
Some prescription drugs
Other approved services

The exact rules and timing can vary by state.

SSDI and health coverage

People who qualify for SSDI typically become eligible for Medicare after a waiting period that starts from the date they are found disabled.

Medicare often includes:

Hospital coverage
Medical coverage
Optional prescription drug coverage

Some people also qualify for both Medicare and Medicaid, depending on income and other factors.

The Disability Application Process: What to Expect

Whether you apply for SSI, SSDI, or both, the basic steps are similar.

1. Submitting your application

You provide:

Personal information (age, contact details, family status)
Work history (for SSDI)
Income and resource details (for SSI)
Information about your health conditions

2. Providing medical and work evidence

The SSA or a state disability agency may request:

Medical records from doctors, hospitals, and clinics
Test results and treatment history
Information about medications and their effects
Details about past jobs and job duties

Sometimes, they may schedule a consultative examination with a medical professional to gather more information.

3. Initial decision and appeals

Many applicants experience one or more of the following:

Initial approval or denial
If denied, the option to appeal within set deadlines
Multiple appeal levels, which can include:
1. Reconsideration
2. Hearing by an administrative law judge
3. Further review at higher levels if needed

The appeals process can take time, but it is a standard part of how disability claims are handled.

Working While on SSI or SSDI

People often wonder how work might affect their SSI or SSDI benefits.

Working and SSI

Because SSI is need-based, earnings from work:

Can reduce your SSI payment
May or may not completely stop benefits, depending on how much you earn
Are treated under specific rules that may allow part of your earnings to be excluded

There are also special work‑incentive rules that can help people test their ability to work while still receiving some support.

Working and SSDI

SSDI is based on work history and disability, not on financial need, but work earnings still matter:

If you earn above a certain monthly level called substantial gainful activity (SGA), the SSA may eventually find that you are no longer disabled for SSDI purposes
There are trial work period and other incentive programs that let you test working without losing benefits right away

These rules are detailed, and many people choose to get individualized guidance before changing work activity while receiving disability benefits.

SSI and SSDI: Quick Takeaways

To keep the essentials clear, here are the core points to remember:

SSI is:
- For people with limited income and resources
- For disabled people of any age and adults 65+
- Based on financial need, not work history
SSDI is:
- For people who worked and paid into Social Security
- For adults whose disability prevents substantial work
- Based on your earnings record, not your current assets
Both programs:
- Use the same basic definition of disability for adults
- Require an application and review of medical and other evidence
- Can provide access to health coverage (Medicaid for many SSI recipients, Medicare for SSDI after a waiting period)
You may qualify for both SSI and SSDI at the same time if you meet the rules for each.

Understanding the difference between SSI and SSDI can help you decide which program (or combination of programs) may fit your situation. From there, the next step is usually to review your work history, income, and resources carefully, gather your medical information, and consider how your conditions affect your ability to work over the long term.