(1) Allowable deductions from income include:

(a) the amount of alimony or spousal maintenance which a parent is required to pay under a court or administrative order.

(b) an amount for the needs of all "other" children as defined in ARM 37.62.103(9) , determined as follows:

(i) When establishing a child support obligation, deduct:

(A) the total of any pre-existing support orders for the other children; and

(B) an amount equal to one-half of the primary child support allowance as found in ARM 37.62.121 for the number of other children for whom no support order exists. These include children who reside with the parent as well as children who do not.

(ii) When modifying a current child support order, deduct the amount determined under ARM 37.62.146.

(c) the amount of any health insurance premium which either parent is required to pay under a court or administrative order for a child not of this calculation;

(d) the actual income tax liability based on tax returns. If no other information is available, use the tax tables which show the amount of withholding for a single person with one exemption;

(e) the actual social security (FICA plus medicare) paid;

(f) actual unreimbursed expenses incurred as a condition of employment such as uniforms, tools, safety equipment, union dues, license fees, business use of personal vehicle and other occupational and business expenses;

(g) actual mandatory contributions toward internal revenue service (IRS) approved retirement and deferred compensation plans. Mandatory contributions are fully deductible;

(h) one-half reasonable expenses for items such as child care or in-home nursing care for the parent's legal dependents other than those for whom support is being determined, which are

actually incurred and which are necessary to allow the parent to work, less federal tax credits. Do not deduct imputed child care expenses when imputing income;

(i) extraordinary medical expenses incurred by a parent to maintain that parent's health or earning capacity which are not reimbursed by insurance, employer, or other entity; and

(j) court ordered payments except as excluded under ARM 37.62.111.

(k) cost of tuition, books and mandatory student fees for a parent who is a full-time student as anticipated under ARM 37.62.106(7) (e) .

(2) Allowable deductions from income for child support differ from allowable deductions for tax purposes.