TurboTax is reporting your 403(b) distribution correctly.
A 403(b) is a type of qualified retirement plan. All distributions from qualified retirement plans are required to be reported on Form 1040 line 16 or Form 1040A line 12, along with distributions from other qualified retirement plans like pensions and any distributions from nonqualified plans.
Form 1040 line 15 and Form 1040A line 11 is exclusively for reporting distributions from IRAs. A 403(b) is not an IRA.
