No. The taxable amount is not necessarily the amount in Box 1.
If box 2a is blank (not zero) on your Form 1099-R form, the taxable portion of your distribution will have to be calculated.
If box 2a has a zero, on your Form 1099-R, then none of the distribution is taxable.
You should enter the information as it appears on your 1099-R form. TurboTax will use the information from your form 1099-R and your answers to the follow-up questions to determine the taxable amount of your distribution.
Click here for additional information on the taxability of distributions when Box 2a is blank or zero.
Click here for "Are IRA or Pension Distributions Taxable?