You need to pay in your tax on a quarterly basis, or as income is earned by quarter if your income varies during the year. While it is true that you will be penalized if your have to pay in more than $1,000 in federal tax when you file your tax return, you can't just wait until the end of the year to pay in your taxes for the whole year.
So, you may have to pay in estimated taxes if you are not paying in enough tax on a quarterly basis. You can use the Form W-4 and estimated taxes option in the Other Tax Forms section in the Other Tax Situations area of TurboTax to see if you need to pay in estimated taxes next year.