My brother is disabled and worked this year. And made about 10,000 before taxes. I usually claim him as a dependent. Am I allowed to claim him this year since he technically doesn’t have to file

No.  He earned too much---he earned over $4200.

"He made about $10,000 before taxes..."     And if he had tax withheld from his pay, he should file a tax return to seek a tax refund.  

Maybe, it depends on the total facts of your situation. Here are the requirements to claim a dependent under the qualifying child rules:

    • They are related to you.
    • They aren't claimed as a dependent by someone else.
    • They are a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
    • They aren’t filing a joint return with their spouse.
    • They are under the age of 19 (or 24 for full-time students).
        ○ No age limit for permanently and totally disabled children.
    • They live with you for more than half the year (exceptions apply).
    • They didn't provide more than half of their own support for the year.
 

As long as he is considered disabled (see IRS definition below), the income limit cited above does not apply. 

So the factor you need to consider is whether you provided more than half of his support during the year. You need to consider total support, housing, food, medical expenses, transportation, food, etc. 

If he paid more than half of his support with his earnings, you should not claim him as a dependent. If you paid more than half of his support, you can claim him as a dependent. 

The IRS defines disability as:

"You have a permanent and total disability if you can't engage in any substantial gainful activity because of your physical or mental condition. A qualified physician must certify that the condition has lasted or can be expected to last continuously for 12 months or more, or that the condition can be expected to result in death." -from Publication 524.