If TurboTax accepts my return for $2216, and the IRS says I get $0 for mathematical errors. Is this part of TurboTax' 100% calculation guarentee?
The TurboTax Accurate Calculation Guarantee will reimburse you for penalties and interest that you have to pay because of an error in the TurboTax calculations.
But the IRS calls almost any error in a tax return a mathematical error. It's usually not an error in the TurboTax calculations. Usually it's something that was entered incorrectly or omitted.
What exactly did the IRS say are the errors in your tax return?
Your post doesn't say that you had to pay any penalties or interest. If you did, and you think there was an error in the TurboTax calculations, go to the following link to submit a claim under the Accurate Calculation Guarantee.
I would check over your return and see if you can see anything wrong especially in the payments section. Make sure you agree with all the amounts listed. Like is the difference the same or close to the refund you got last year? Maybe you put down that you applied last year's refund to this year? Or you applied part of your refund to next year as an estimated payment. Or you put down you made a payment with an extension or paid an estimated payment that you didn't make?
Do you get Social Security? Is there an amount on 1040 line 6b or is it 0?
There is a new question this year asking if you lived in a foreign place. People have been answering it wrong or skipping it. Go back through the Social Security entries. And it is for each spouse. So if you have a low amount on 1040 line 6b you might have answered wrong for 1 person.