Yes. If you are not the custodial parent (noncustodial parent), then this Form 8332 is required to be sent to the IRS with the Form 8453. This form must be completed and signed by the custodial parent. If you failed to mail it to the IRS after your return was accepted, then they may have changed your tax return to remove the child.
If so, you can file an amendment, claiming the child as a dependent. Select zero months child lived with you and indicate you have Form 8332 and then file the Form 1040X with Form 8332 and mail it to the IRS. The amended return is not allowed to be filed electronically. Form 8453 is no longer required on an amended tax return.
Read all instructions carefully before you begin, the original return (column) on the amendment should reflect the figures after the IRS changed it. You are amending their changes, not the return the way you originally filed it.
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