I received a 1099 NEC from a company I did consulting work for. I am not an employee and I have another full time job for which I receive a W-2 etc. Tax owed is > 15.3%

[ggayle0520]

The taxes calculated by TurboTax appear greater than 15.3% (SS & Medicare).  Also, I exceeded by SS tax income on my full time job so I should I  not owe any SS tax on this 1099 NEC income?

[VolvoGirl]

Right the W2 SS in box 4 counts towards the max SS you pay on all your income.   Social Security maxes out when you reach $137,700 income (sched C profit + any W2 wages).  You need to look at your whole return and schedule C and schedule SE.  

Also you owe regular income tax on the Net Profit in addition to the Self Employment tax.  And by increasing your income you may reduce some deductions and credits you qualified for.  When you entered more  income you can't just watch the monitor. You increased your overall adjusted gross income and with that come many other changes in your return, not just the incremental tax on the one transaction. More income can make more of any Social Security taxable.

And if you owe too much you may have a penalty on  line 38.  

Are you using the Online version?  Before filing you can preview the 1040 or print the whole return. You have to pay any fees first before you can see all the forms, etc.
https://ttlc.intuit.com/community/accessing/help/how-do-i-preview-my-turbotax-online-return-before-f...