Tax Rules for Claiming Adult Dependents

You can claim certain adults as your dependents on your tax return, but it's subject to a lot of rules. The adult must live with you and receive more than half of their support from you. This adult dependent also can't earn more than a certain amount of money. It's important to consider whether you can claim an adult dependent because dependents open the door to being able to claim multiple tax breaks, and it increases the benefits of others.

Defining Dependents for Tax Purposes

The Internal Revenue Service (IRS) defines a dependent in a rather vague way: it’s someone “other than the taxpayer or spouse” who qualifies the taxpayer to claim a dependency exemption. In practical terms, it’s someone who literally “depends” on the taxpayer for support, and multiple IRS rules determine whether this is indeed the case.

All dependents are either qualifying children or qualifying relatives other than a spouse, and they’re subject to varying requirements depending on which category they fall into.

You can benefit from claiming dependents because having them can make you eligible for other tax perks, including the advantageous head of household filing status and the child and dependent care tax credit. There is also a tax credit for non-child dependents.

The Credit for Other Dependents

Known as the "credit for other dependents," this tax credit entitles you to a credit for certain other dependents who don't meet the requirements for the child tax credit.

Your dependent doesn’t have to be your child to allow you to claim this credit. They can be your parent, sibling, or cousin—or not even related to you at all. They must meet all the other IRS qualifying rules for adult dependents, however. The credit is $500 per dependent, but your eligibility to receive it phases out if you earn more than $200,000 (or $400,000 if you're married and filing jointly).

What Qualifies Someone as a Dependent?

All dependents must be U.S. citizens, nationals, resident aliens, or residents of Canada or Mexico. They can’t file a joint return with a spouse if they’re married unless it’s solely for the purpose of claiming a refund because they owe no taxes. Dependents can’t claim dependents of their own.

These rules apply to all dependents, but others apply separately to qualifying children or relatives.

The Relationship Rule

You must have a qualifying relationship with your would-be dependent. The individual must be either a close relative or must live with you.

Qualifying relatives include siblings, half-siblings, and step-siblings. They also include your parents, step-parents, grandparents, and even great-grandparents. Nieces, nephews, aunts, and uncles can all be your dependents, and your in-laws are covered by this rule, too.

Your adult children might also qualify as your dependent if you continue to support them—they're just no longer your “qualifying children” if they're 19 or older, or age 24 or older if they're students. They become “qualifying relatives" instead.

All of these related individuals can be your dependents without actually living with you, but unrelated adults must reside in your home. The relationship can be with either you or your spouse if you file a joint return.

Your relationship with an unrelated dependent can’t be against the law in your state. For example, you might live with your significant other and meet all the other rules, but your living arrangement might be considered illegal if they’re married to someone else. You couldn’t claim them as a dependent as a result.

The Income Rule

There must also be a good reason why your would-be dependent is costing you so much money, namely that they earn very little money of their own.

Their total taxable income from all sources must be less than the personal exemption amount for the year in which you want to claim them—that amount is $4,400 for tax year 2022.

The Support Rule

Even assuming that your dependent meets the income rule, what they do with their money also matters. The support rule requires that you provide more than 50%—more than half—of their support.

Let’s assume that your sibling earned $4,000 last year, so they would come in just under the wire on the income test. They rent a room in someone’s home, and their entire monthly living expenses are $500, or $6,000 a year. They use their entire income to pay these expenses, and you pay the $2,000 balance.

They’re not your dependent because you don't provide more than half their support. They can’t qualify even though they’re a relative who doesn’t have to live with you, and even though they earn less than the personal exemption for the year, because you’ve contributed just one-third to their support. 

Suppose instead this sibling's monthly living expenses were $1,000 a month or $12,000 a year, and they contributed all of their $4,000 income. If you were to pay the rest ($8,000 a year), then they would qualify as your dependent, because you paid more than half of their expenses for the year.

Multiple Support Agreements

The support that your would-be dependent receives from others counts, too. Maybe you have two other siblings, and they both contribute some money every month to help the one who’s down on their luck. Your personal contribution must still be 50% or more unless your siblings sign Form 2120, the multiple support declaration form.

A multiple support agreement often comes into play when siblings pool their money to support elderly parents. The agreement simply states the consent of the others to not claim the individual in question as a dependent. You must still contribute a minimum of 10% to their support, but this is considerably less than the 50% or more rule.

The Bottom Line

These rules are complicated. The IRS anticipates that many taxpayers will have problems trying to figure out who they can claim and who they can't, so it provides an interactive tool on its website to help you along. Answer some questions, and the tool will give you a yes or no answer. The process takes less than 15 minutes.

Frequently Asked Questions (FAQs)