Section 154.061 - Computing Net Monthly Income(a) Whenever feasible, gross income should first be computed on an annual basis and then should be recalculated to determine average monthly gross income.(b) The Title IV-D agency shall annually promulgate tax charts to compute net monthly income, subtracting from gross income social security taxes and federal income tax withholding for a single person claiming one personal exemption and the standard deduction.Added by Acts 1995, 74th Leg., ch. 20, Sec. 1, eff. 4/20/1995.