Not sure what you mean by "child refund"---are you referring to a child-related credit you did not get? Code 9021 refers to a math or calculation error made on your return. Something you entered may have been entered incorrectly. Or was there a mis-match between income you entered and income entered by an employer or client who paid you? TurboTax's calculations are accurate--but they are based on the data you entered, so you may have entered something incorrectly, resulting in the 9021 message. Double-check your own data entries.