(1) The guidelines create a presumption of the adequacy and reasonableness of child support awards. However, every case must be determined on its own merits and circumstances and the presumption may be rebutted by evidence that a child's needs are or are not being met.

(2) At the request of one of the parties and upon consideration of the factors set out in the guidelines and in 40-4-204 , 40-4-208 and 40-6-116 , MCA, the guidelines may be rebutted and a variance from the guidelines amount may be granted. Any consideration of a variance from the guidelines must take into account the best interests of the child.

(3) The support order may vary from the guidelines in a particular case only if the decree, separation order or support order contains a specific written finding showing justification that application of the guidelines would be unjust or inappropriate, based upon evidence sufficient to rebut the presumption.

(4) Findings that rebut and vary the guidelines must include a statement of the amount of support that would have been ordered under the guidelines without the variance.

(5) Child support may vary from the guidelines based on a stipulation or agreement of the parties only if the stipulation or agreement meets the following criteria:

(a) it is in writing executed by the parties or is entered by a court or administrative proceeding;

(b) the parties have signed the stipulation or agreement free of coercion;

(c) it contains specific justification as to why application of the guidelines is unjust or inappropriate; and

(d) it contains a statement of the amount of support that would have been appropriate under the guidelines without the variance.

(6) A support order granting a variance, based upon the existence of a condition or the performance of an act, must provide that, upon termination of the circumstances which justify the variance, the support immediately reverts to the amount which would have been ordered under the guidelines without the variance.