1.    An employer’s reserve ratio is the difference between the six-year contributions paid by that employer on or before October thirty-first of any year, with respect to wages paid by that employer before October first of that same year, and the six-year benefits charged to that employer’s account before October first of that year, divided by the average annual payroll. Employers whose cumulative contributions exceed cumulative benefits must be assigned within the positive employer rate groups. Employers whose cumulative contributions are equal to or less than cumulative benefits must be assigned within the negative employer rate groups.

2.    For each calendar year the bureau shall establish a schedule of positive employer rate groups within the positive employer minimum rate and the positive employer maximum rate determined under section 52-04-05. Each successive rate group for positive employer rate groups must be assigned a rate equal to one hundred twenty percent of the previous group’s rate with a minimum increase of one-tenth of one percent and a maximum increase of four-tenths of one percent. The number of rate groups in the positive employer schedule must be ten. For each calendar year the bureau shall establish a schedule of negative employer rate groups with the negative employer minimum rate and the negative employer maximum rate determined under section 52-04-05. Each successive rate group for negative employer rate groups must be assigned a rate equal to the previous group’s rate plus four-tenths of one percent. The number of rate groups in the negative employer schedule must be the number required to provide for a rate group at each four-tenths of one percent interval between the negative employer minimum rate and the negative employer maximum rate determined under section 52-04-05. All results calculated under this subsection must be rounded to the nearest one-hundredth of one percent.

3.    Positive employers must be assigned to the rate in the positive employer rate schedule in the rank order of their reserve ratios, as determined in subsection 1, with the highest reserve ratio positive employers assigned to the first positive employer rate. Each successively ranked positive employer must be assigned to a rate within the positive employer rate schedule so that the first rate within the rate schedule is assigned sixty percent of the positive employer’s prior year’s taxable wages and each of the remaining nine rates within the rate schedule are assigned the same proportion of the remaining forty percent of the positive employer’s prior year’s taxable wages. Negative employers must be assigned to the rate in the negative employer rate schedule in the rank order of their reserve ratios, as determined in subsection 1, with the highest reserve ratio negative employers assigned to the first negative employer rate. Each successively ranked negative employer must be assigned to a rate within the negative employer rate schedule so that each rate within the rate schedule is assigned the same proportion of the negative employer’s prior year’s taxable wages.

4.     a.    After each year’s rate schedule has been established, an employer may pay into the fund, or cause to be paid into the fund on the employer’s behalf, an amount in excess of the contributions required to be paid under this section. That amount must be credited to the employer’s separate account. The employer’s rate must be recomputed with the amount paid pursuant to this subsection included only, except as allowed by subdivision b, if that amount was paid by April thirtieth of that year. Payments may not be refunded or used as credit in the payment of contributions.

b.    An employer that enters a contract with a staffing service, other than a temporary staffing service, may make the payments authorized by this subsection at any time during the rate year and the agency will determine if that payment is adequate to allow the staffing service to comply with subsection 3 of section 52-04-24; however, the employer’s tax rate will remain in effect for the remainder of the tax year. The agency will deposit any payment received pursuant to this subsection immediately and will credit it to the employer’s separate account, but the agency will apply the payment to the calculation of the employer’s tax rate for the following rate year. In order to take advantage of this subdivision and subsection 3 of section 52-04-24, an employer may not be delinquent in its unemployment insurance tax payments on the date on which the payment authorized by this subdivision is made.

5.    In the bureau’s determination of the projected income requirements for computing contribution rates and taxable wage base, only the wages paid by, and the cost of benefits attributable to, tax-rated employers may be taken into account.

6.    If an employer has a quarterly taxable payroll in excess of fifty thousand dollars and at least three times its established average annual payroll or the average annual payroll is zero, and the employer’s cumulative lifetime reserve balance is positive, then the tax rate for that employer is ninety percent of the positive employer maximum rate in effect that year or a rate of one percent, whichever is greater, beginning the first day of the calendar quarter in which it occurred and for the remainder of the calendar year. If the employer’s cumulative lifetime reserve balance is negative, then the tax rate for that employer is the negative employer maximum rate of contribution in effect that year, beginning the first day of the calendar quarter in which it occurred and for the remainder of the calendar year.