I am a 22 year old full-time student who claimed independent. Are my parents still able to claim me?

[DoninGA]

No.  Since you did not indicate on your tax return that you can be claimed as a dependent, then your parents cannot claim you as a dependent on their tax return.  If you incorrectly filed your tax return with the wrong dependency status, amend the return to change your dependency.

See this TurboTax support FAQ for amending a 2018 tax return - https://ttlc.intuit.com/community/amending/help/how-do-i-amend-a-return-in-turbotax/01/27579

Amended tax returns can only be printed and mailed, they cannot be e-filed.  It will take the IRS 16 weeks or longer to process an amended return.  Your parents can claim you as a dependent on their tax return but will only be able to mail the tax return since your tax return has already been accepted by the IRS with your current non-dependent status.

[Hal_Al]

No. if you did not check the box (or have Turbotax check it for you), on form 1040, saying that you can be claimed as a dependent, then you parents cannot claim you. 

However, you can file an amendment return, unclaiming your self, and that will allow them to claim you.  They do not need to wait for your amended return to be fully processed. But, they cannot e-file. they have to mail in a paper return.

if your income is from earned income (wages or self employment) or even taxable scholarships, you pay the same tax (or get the same refund) regardless of whether you are a dependent or not. This is new for 2018. That was not true in past years.

The real question is: do you qualify as your parent's dependent.  There are two types of dependents, "Qualifying Children"(QC) and standard ("Qualifying Relative" in IRS parlance even though they don't have to actually be related). There is no income limit for a QC but there is an age limit, a relationship test and residence test. Only a QC qualifies a taxpayer for the Earned Income Credit.

A child of a taxpayer can still be a “Qualifying Child” (QC) dependent, regardless of his/her income, if:

1. He is under age 19, or under 24 if a full time student for at least 5 months of the year, or is totally & permanently disabled
2. He did not provide more than 1/2 his own support. Scholarships are considered third party support and not as support provided by the student.
3. He lived with the parent (including temporary absences such as away at school) for more than half the year

If you do not meet the rules for a QC, then you cannot be your parent's  standard dependent, if you have more than $4150 of reportable income.  See full rules at:

https://turbotax.intuit.com/tax-tools/tax-tips/Family/Rules-for-Claiming-a-Dependent-on-Your-Tax-Ret...