A Traditional IRA is generally 100% taxable on the federal return.

All of it is taxable, most likely. The only way that its not 100% taxable is if you made nondeductible contributions into the IRA when you were contributing.

Many 1099-Rs say "Taxable Amount Not Determined." When it comes to Traditional IRAs, however, its not common for any of it to not be taxed. Age is not a factor in this.

After you input the 1099-R, continue past the 1099-R summary screen. You will be asked if you made nondeductible contributions. If you did, the program will calculate the taxable amount based on 1/ the total after-tax contributions you made and b/ the value of the account on 12/31/2016. You would have filed Form 8606 in the past if you made nondeductible contributions. If you indicate that no nondeductible contributions were made, the amount in Box 1 will be taxed.

Are you asking about your state too? You will need to specify which state you live in.