1040 Line 16 discrepancy

On my 1040 for tax year 2023, line 15 is 109,201 and line 16 is 14,587.  By my calculation (and at least one online calculator), line 16 should be 14,639.  None of the special form boxes on line 16 apply, status is Married Filing Jointly.  I'm trying to figure out how TT arrived at the lower number.