Add the gross earnings from all trades or businesses carried on by the self-employed person, to compute net earnings.

Include their distributive share of income from a partnership of which they are a general partner.

Exclude any types of income so specified by the Act or the Internal Revenue Code (IRC).

Subtract any ordinary and necessary expenses incurred in carrying on the business.

Multiply the result by .9235 (i.e., 100% - 7.65% = 92.35% or 0.9235) to derive the NESE, beginning with taxable years after 12/31/89.