According to the government's web site, Line 37 is used as AGI for qualification of the ACA. According to TurboTax's 'info' button during filing, if your income is just below $47,080 you are only required to payback up to $1,275.
My line 37 is below $47.080 but TurbTax is filing that I have to pay back $10,445 or all of the tax credits.
You appear to be referring to the repayment cap for the advanced premium tax credit. Based on your expectation of a $1275 cap, it appears that you are single with no dependents. It also appears that you believe that your modified adjusted gross income falls below 400% of the federal poverty line. The tax credit for 2017 (assuming the 48 contiguous states and District of Colombia), would be based on the 2016 100% federal poverty line of $11,880. So the MAGI would need to be under $47,520 for the repayment cap. The repayment limitation should be recorded on Line 28 in Part III of the Form 8962. Please note that Line 37 of Form 1040 is AGI not MAGI. So, to move forward, I can only suggest that you obtain Form 8962 and the Instructions for Form 8962. Follow the Form 8962 instructions and compare your results with the results in your initial tax return to try to isolate the area that might be causing the problem. Note that tax-exempt income and foreign earned income can modify your AGI according to the instructions for Line 2a of the Form 8962. Also check the instructions for Line 28 of Form 8962 to be sure that none of the exceptions for the limitation will apply to your situation. Finally verify that all inputs are correct. Otherwise, I hope that someone else will be able to assist because I am out of ideas.