You have to report the amount in Box 5 of the SSA-1099.
Up to 85% of the Social Security benefits you receive can be taxable income based on the other income on the return.
The amount in Box 5 cannot be netted against Social Security paid in on the pay-stubs during the year. If you did this, IRS may send you a letter due to the SSA-1099 not matching and would adjust the tax on the return, with interest and possibly penalty.