Disability insurance can replace your income if you can't work because of illness or injury. However, disability insurance policies offered through your employer or the government are rarely enough to cover all monthly expenses. Supplemental disability insurance fills coverage gaps and provides additional financial support if you are unable to work because of a disability.
The main two types of supplemental disability insurance are long-term or short-term policies, and which one you need depends on what type of coverage you already have. (Most people benefit from buying a supplemental long-term disability insurance.) Your total disability insurance amount should be roughly equivalent to your take-home pay (post-tax income).
Do I need supplemental disability insurance?
One in four 20-year-olds will become disabled before reaching retirement age.  You should consider supplementing your current disability insurance policy if you:
Have a policy with a short benefit period: Policygenius experts recommend a benefit period of at least five years.
Don't have enough coverage to replace gross income: If your existing policy doesn’t pay enough each month for you to cover necessities, supplemental coverage will fill the gaps.
Only have disability coverage through work: Group disability is affordable and easy to get, but if you leave your job you lose the policy. You may be able to buy supplemental coverage through your employer (voluntary disability coverage), but make sure you get to keep the coverage if you leave your job before considering this option.
Don't have own-occupation disability insurance: If you have any-occupation disability insurance, you only receive a payout if you can’t work any job. Own-occupation is more comprehensive and provides a benefit if you lose the ability to work in your current profession.
Supplemental long-term disability insurance is the best option for most people. A long-term disability policy can be customized and stays with you even if you change jobs.
Note that supplemental disability insurance is different than Medicare supplement insurance, for which you may be eligible if you're on Medicare due to a disability.
How much supplemental disability insurance do you need?
Supplemental coverage is based on existing disability insurance. Since many people get short-term disability insurance through work, they need to get supplemental long-term disability insurance.
Find out how much coverage you have with any current plans
Most people who need supplemental disability insurance have one of the following types of insurance:
Group disability insurance: Many employer plans cover up to 60% of your income, but that 60% payment is taxed if your company covers any of your premiums. 
Social Security Disability Insurance: SSDI benefits are difficult to qualify for and come with a five-month waiting period. The average monthly benefit was $1,234 in 2019,  far less than most people need.
State disability insurance: California, Hawaii, New Jersey, New York, Rhode Island, and Puerto Rico all provide temporary disability insurance.  The benefits available vary by location.
Calculate monthly expenses and compare the total to your current disability benefits
The gap between your existing coverage and your monthly expenses (including housing, food, childcare, recurring bills, and debt payments) is how much supplemental disability insurance you need. For example, if your monthly expenses are $3,000 and your employer offers $1,500 a month in disability insurance, you'll ideally need $1,500 in supplemental coverage.
Consider waiting periods
Look at the length of your benefit period and when your payments will start (also called the waiting period or elimination period). Elimination periods typically last 90 days, which can leave you financially vulnerable. Talk to your licensed disability insurance broker about supplemental insurance to cover that downtime.
How much does supplemental disability insurance cost?
Disability insurance typically costs 1% to 3% of your annual salary, based on industry data in 2023. For example, if you earn $50,000 a year, you can expect to pay between $60 to $125 per month for disability insurance. Your supplemental disability rates depend on:
You’ll save money by purchasing only the amount of coverage you need to complement your existing disability plan instead of relying entirely on a private plan for income protection. This comes at the risk of losing your current coverage, especially if you’re supplementing group insurance.
You can speak to a licensed agent at Policygenius to get supplemental disability insurance quotes today.
How to buy supplemental disability insurance
Here are the steps to take when getting supplemental disability insurance:
Calculate how much coverage you need, when you want payments to start, and how long you want benefits to last.
Consider adding riders to customize your policy.
Compare quotes from different insurance companies.
Fill out an application with a trusted disability insurance broker.
Go through underwriting, which will include a phone interview, occupational review, and medical exam.
Accept and sign your policy.
An ideal disability insurance policy protects your income if an injury or illness prevents you from earning a living. If your existing disability plan is lacking, supplemental disability insurance will ensure you’re protected.
Frequently asked questions
How does supplemental disability insurance work?
Supplemental disability is a private disability policy you can buy to fill any gaps in your employer- or government-provided disability insurance.
Is supplemental disability insurance worth it?
A supplemental policy is worth considering if your existing insurance has limited benefits, so your income is fully protected if you become disabled.
How much additional coverage should I buy?
Calculate your monthly expenses and subtract the amount you’ll receive from your current disability plan. The amount remaining is how much you need to supplement.