the estimate tax penalty on line 38 is just that an estimate. (don't know if there was a bug in Turbotax) Sometimes the info the IRS has like estimated tax payment dates will differ from what the taxpayer has entered then line 38 is can be too high or too low.
you do have options
1) pay it and do nothing else.
the following options would be to see if you can lower the penalty
2) use the annualized income installment method
3) if you had withholding use actual withholding for 1/1-4/15, 4/16 -6/15 and 6/16-9/15 and 9/16-12/31
4) both 2 and 3.
I'm not sure how you can check the IRS calculation vs the one Turbotax did. however, since you are using desktop you can see Turbotax calculations by using the search box for form 2210. Forms>open form>2210. then double click on the form to open it.
