Get your taxes done using TurboTax

Ernie has provided a nice answer, but it doesn't work in practice. 

I pay estimated taxes, my income is very uneven during the year, and I must use the Annualized Income Installment Method to determine any underpayment (and the resulting penalty).  The IRS and CA penalty waivers only apply to Q4 payments; I must still complete Form 2210AI for the first 3 quarterly payments.

You can't  use the Annualized Income Installment Method and check Form 2210 Box C (Check to have the IRS figure the penalty and send a bill if penalty due).  If you try to do this, TT will throw this error message:

Part II, Box C *is* checked (as it must be), because I am using the Annualized Income Installment Method.

If I follow Ernie's advice, I will end up being (erroneously) billed for a massive underpayment penalty.  Sure, I can get it sorted out with a lot of work, but no thank you.

.