Answer:  You must make estimated tax payments for the current tax year if both of the following apply:

• You expect to owe at least $1,000 in tax for the current tax year after subtracting your withholding and refundable credits.
• You expect your withholding and refundable credits to be less than the smaller of:  90% of the tax to be shown on your current year’s tax return, or 100% of the tax shown on your prior year’s tax return. (Your prior year tax return must cover all 12 months.)