I need to check the box that says "someone else can claim me as a dependent" but I have already filed. How can I fix that?

[DoninGA]

If the IRS accepts your tax return you will have to amend the return to change your dependency status.

You will have to wait for the IRS to either Accept or Reject your filed federal tax return.
If the return is rejected you can make the necessary changes and e-file again.
If the return is accepted you will have to amend your original tax return. An amended return, Form 1040-X, can only be printed and mailed to the IRS if the original tax return was not e-filed. The IRS will take up to 12 weeks or longer to process an amended tax return.

Before starting to amend the tax return, wait for the tax refund to be received or the taxes due to be paid and processed by the IRS.

See this TurboTax support FAQ for amending a current year tax return - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-federal-tax-return-curr...

[CatinaT1]

You will need to amend your return.

If you want to make changes or add a document to a tax return that has already been filed and accepted by the taxing agency, you should follow these guidelines. 

• You must first wait until the initial return is completely processed. 
• You will have to use the same TurboTax account that you used for the original tax return. 
• Once you begin your amendment, you'll see your original return.  
• The refund calculator will start new at $0 and only reflect the changes in the refund or tax due 
• Only make changes to the areas of your return that need to be corrected. 
• You have three years from the date you filed your return or two years after you paid the tax due (whichever is later) to file an amendment 

Select your product below and follow the instructions. 

Amend TurboTax Online 

Amend TurboTax CD/Download