Hi! According to irs.gov, If you overpaid tax, you can have all or part of the overpayment refunded to you, or you can apply all or part of it to your estimated tax. If you choose to get a refund, it will be sent separately from any refund shown on your original return.
https://www.irs.gov/publications/p17/ch01.html they do not make this information easy to see. You will find it in the section marked Amended Returns and Claims for Refund.
