The deduction for seniors is a deduction, not a credit. You don't have to enter anything to get the deduction for seniors. TurboTax will give it to you automatically based on the birth date that you entered in your personal information, and your income.
Are you looking for the deduction in the right place? It is not an itemized deduction. The deduction for seniors is calculated in Part V of Schedule 1-A. The amount of the deduction is on Schedule 1-A line 37. The total deductions from Schedule 1-A will be on Form 1040 line 13b, which might include other deductions besides the deduction for seniors.
The maximum deduction for seniors is $6,000, or $12,000 if married filing jointly and both are 65 or older. The deduction is gradually reduced if Modified Adjusted Gross Income (MAGI) is over $75,000 ($150,000 if married filing jointly), so if your income is over that amount you will not get the full $6,000 per person. The deduction is reduced to zero if MAGI is $175,000 or more ($250,000 if married filing jointly).
