Okla. Stat. tit. 43, § 43-115: Order for child support or modification of order -

Provision for income assignment.

A. Every order providing for the support of a minor child or a

modification of such order, whether issued by a district court or an

administrative court, shall contain an immediate income assignment

provision if child support services are being provided under the

state child support plan as provided under Section 237 of Title 56

of the Oklahoma Statutes, regardless of whether support payments by

such parent are in arrears.

B. In all child support cases arising out of an action for

divorce, paternity or other proceeding in which services are not

being provided under the state child support plan, the district

court shall order the wage of the obligor subject to immediate

income assignment, regardless of whether support payments by such

parent are in arrears, unless:

1. One of the parties demonstrates and the district court finds

there is good cause not to require immediate income withholding; or

2. A written agreement is reached between the parties which

provides for an alternative arrangement.

C. The obligated party may execute a voluntary income

assignment at any time. The voluntary assignment shall be filed

with the district or administrative court and shall take effect

after service on the payor, as required by Section 1171.3 of Title

12 of the Oklahoma Statutes.