When I sell my business , do I have to recognize the total gain in that tax year ?

You and your local CPA can structure the sale using the installment method. The installment method is a special method of reporting gains from sales of property where at least one payment is received in a tax year after the year of sale. Under the installment method gain from an installment sale is prorated and recognized over the years in which payments are received. The installment gain is reported on IRS Form 6252.