Child Support Guideline Models


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States generally use one of three models to determine the base child support amount due. Explanations of each model and the states that use them follow.

The Income Shares Model is based on the concept that the child should receive the same proportion of parental income that he or she would have received if the parents lived together. In an intact household, the income of both parents is generally pooled and spent for the benefit of all household members, including any children. Forty-one states, Guam and the Virgin Islands use the income shares model: Alabama, Arizona, Arkansas, California, Colorado, Connecticut, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, Nebraska, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Utah, Vermont, Virginia, Washington, West Virginia, Wyoming, Guam, Virgin Islands.

Guideline Models The Percentage of Income Model sets support as a percentage of only the noncustodial parent's income; the custodial parent's income is not considered. This model has two variations: the Flat Percentage Model and the Varying Percentage Model. Six states (Alaska, Mississippi, Nevada, North Dakota, Texas, Wisconsin) use the percentage of income model. Four states (Alaska, Mississippi, Nevada and Wisconsin) use the flat percentage model while the other two states (North Dakota and Texas) use the varying percentage model.

The Melson Formula is a more complicated version of the Income Shares Model, which incorporates several public policy judgments designed to ensure that each parent's basic needs are met in addition to the children's. The Melson Formula was developed by a Delaware Family Court judge and fully explained in Dalton v. Clanton, 559 A.2d 1197 (Del. 1989). Only three states (Delaware, Hawaii and Montana) use the Melson Formula.

The District of Columbia uses a hybrid model that starts as a varying percentage of income model and is then reduced by a formula based on the custodial parent's income. Use the links in the chart below to view these guidelines.

All of the guideline models have certain aspects in common. First, most of the guidelines incorporate a "self-support" reserve for the obligor. Second, all the guidelines have a provision relating to imputed income. Third, by federal regulation, all the guidelines take into consideration the health care expenses for the children, by insurance or other means. Lastly, most of the guidelines have incorporated into the presumptive child support formula special additions for child care expenses, special formulas for shared custody, split custody, and extraordinary visitation, and special deductions for the support of previous and subsequent children.

Guideline Models by State

State/ Territory

Guideline Type

Link to Guidelines


Income Shares

Ala. R. Jud. Admin. R. 32


Percentage of Obligor's Income

Alaska Civ. R. 90.3


Income Shares

Arizona Child Support Guidelines


Income Shares

Ark. Admin. Order of the Supreme Court, Rule 10


Income Shares

California Fam. Code §§ 4050-4076


Income Shares

Colo. Rev. Stat. §§ 14-10-115 et seq.


Income Shares

Child Support and Arrearages Guidelines


Melson Formula

Delaware Child Support Guidelines

District of Columbia

Hybrid Model

D.C. Code Ann. § 16-916.01


Income Shares

Fla. Stat. Ann. § 61.30


Income Shares

Ga. Code Ann. § 19-6-15


Income Shares

Guam Child Support Guidelines


Melson Formula

Hawaii Child Support Guidelines


Income Shares

Idaho R. Civ. Pro. 6(c)(6)


Income Shares

Ill. Rev. Stat. ch. 750, § 5/505 through Ill. Rev. Stat. ch. 750, §5/510


Income Shares

Indiana Child Support Rules and Guidelines


Income Shares

Iowa Child Support Guidelines


Income Shares

Kansas Admin. Order No. 307


Income Shares

Ky. Rev. Stat. § 403.212


Income Shares

La. Rev. Stat. 9:315.1 et seq.


Income Shares

Me. Rev. Stat. Ann. tit. 19-A, §§ 2001-2012


Income Shares

Md. Fam. Law Code Ann. §§ 12-201 et seq.


Income Shares

Massachusetts Child Support Guidelines


Income Shares

Michigan Child Support Formula Manual; Mich. Comp. Laws § 552.605 et.seq.


Income Shares

Minn. Stat. Ann. §§ 518A.35 et seq.


Percentage of Obligor's Income

Miss. Code §§ 43-19-101 et seq.


Income Shares

Mo. Rev. Stat. § 452.340 

Civil Procedure Form 14


Melson Formula

Admin. R. Mont. 37.62.101 et.seq.


Income Shares

Nebraska Court Rules §§ 4-201 to 4-220


Percentage of Obligor's Income

Nev. Admin. Code 425 et seq.

New Hampshire

Income Shares

N.H. Rev. Stat. §§ 458-C:1 to -:7

New Jersey

Income Shares

N.J. Rules of Court, Rule 5:6A, Appendix IX

New Mexico

Income Shares

N.M. Stat. §§ 40-4-11.1 to -11.6

New York

Income Shares

N.Y. Dom. Rel. Law. § 240(1-b)

North Carolina

Income Shares

North Carolina Child Support Guidelines

North Dakota

Percentage of Obligor's Income

N.D. Admin. Code §§ 75-02-04.1-01 to13;


Income Shares

Ohio Rev. Code §§ 3119.01 et seq.


Income Shares

Okla. Stat. tit. 43, §§ 118 to 120


Income Shares

Or. Admin. Reg. 137-50-320 to -490


Income Shares

Pa. R. Civ. Pro. 1910.16-1 to -5

Rhode Island

Income Shares

R.I. C.S.G. Administrative Order

South Carolina

Income Shares

S.C. Soc. Serv. Reg. 114-4710 to -4750

South Dakota

Income Shares

S.D. Codified Laws §§ 25-7-6.1 et seq.


Income Shares

Tenn. Comp. R. & Regs. Dep’t Human Services 1240-2-4-.01 to -.057


Percentage of Obligor's Income

Tex. Fam. Code §§ 154.001 et seq.


Income Shares

Utah Code §§ 78B-12 et seq.


Income Shares

Vt. Stat. title 15, §§ 653-657


Income Shares

Va. Code §§ 20-108.1, 20-108.2


Income Shares

Wash. Rev. Code §§ 26.19.001 et seq.

West Virginia

Income Shares

W. Va. Code Ann. §§ 48-13-101 to -803


Percentage of Obligor's Income

Wis. Admin. Code DCF 150.01 to .05


Income Shares

Wyo. Stat. §§ 20-2-301 to -315


As you can see in the chart above, child support guidelines are implemented in different ways. Twenty-four states and D.C. implement the guidelines in statute, seventeen states use court rules or decisions and the remaining nine states have implemented the guidelines through administrative regulation. See the breakdown here:

Model of Implementation


California, Colorado, District of Columbia, Florida, Georgia, Illinois, Kentucky, Louisiana, Maine, Maryland, Michigan, Minnesota, Mississippi, New Hampshire, New Mexico, New York, Ohio, Oklahoma, South Dakota, Texas, Utah, Virginia, Washington, West Virginia, Wyoming

Administrative Regulation

Connecticut, Montana, Nevada, North Dakota, Oregon, South Carolina, Tennessee, Vermont, Wisconsin

Court Rule or Decision

Alabama, Alaska, Arizona, Arkansas, Delaware, Hawaii, Idaho, Indiana, Iowa, Kansas, Massachusetts, Missouri, Nebraska, New Jersey, North Carolina, Pennsylvania, Rhode Island

Contact Us

For more information or to request technical assistance on state or federal child support policies and programs, please send a message to Children & Families staff. As a membership organization serving state legislators and legislative staff, we do not respond to inquiries or provide legal advice related to individual child support or family law cases.

Additional Resources