Child Support & Alimony Guide (2026): Calculations, Laws, and Modifications

A plain-language guide to child support calculations, alimony types, enforcement, and state-by-state guidelines.

Created to help people understand support obligations in plain language. Laws and procedures vary by state.

Support at a Glance

~$5,200

Average annual child support per case

~13.9M

Custodial parents in the U.S.

41 states

Use the income-shares model

50 states

Each with unique support formulas

This page is for informational purposes only and does not constitute legal advice. For advice specific to your situation, consult a licensed attorney in your state.

What This Guide Includes

  • How child support is calculated
  • Alimony types and duration
  • Filing for and modifying support
  • Enforcement and collections
  • State-by-state guidelines and formulas
  • Support calculators and tools

This page is designed as a starting point before speaking with a lawyer.

Common Questions About Support

How is child support calculated?
Most states use the income-shares model, which estimates how much parents would have spent on children if together. Both incomes are combined, a percentage is applied based on the number of children, and each parent pays their proportional share. Try our child support calculator or see the guidelines for all 50 states.
Can child support be modified?
Yes. Either parent can request a modification if there's a significant change in circumstances — such as job loss, income change, or a change in custody. The court must approve any modification.
How long does alimony last?
Duration varies by type and state. Temporary alimony lasts during divorce proceedings. Rehabilitative alimony typically lasts 3–5 years. Permanent alimony is increasingly rare and usually reserved for long marriages where one spouse has limited earning capacity.

Detailed Guides and Articles

In-depth articles covering every aspect of support.

More Guides

Support

Child Support in South Carolina: Guidelines and Calculations

How child support is calculated in South Carolina using the Income Shares Model. Learn about shared custody adjustments, the 109-overnight threshold, modification rules, and enforcement.

14 min read · Updated May 2026
Support

Child Support in Colorado: Guidelines and Calculations

How child support is calculated in Colorado using the Income Shares Model. Learn about Worksheet A vs. B, the 92-overnight threshold, imputed income rules, modification, and enforcement.

14 min read · Updated April 2026
Support

How to Modify Alimony: Process and Requirements

Learn how to modify alimony payments — grounds for modification, the court process, required documentation, non-modifiable orders, and state-specific rules.

14 min read · Updated April 2026
Support

Child Support in Missouri: Guidelines and Calculations

How child support is calculated in Missouri using Form 14 and the Income Shares Model. Learn about parenting time credits, overnight adjustments, modification rules, and enforcement.

13 min read · Updated April 2026
Support

How Cohabitation Affects Alimony

How moving in with a new partner can reduce or end alimony — cohabitation definitions, state-by-state rules, how courts evaluate it, and how to prove or defend against a claim.

10 min read · Updated April 2026
Support

Child Support in Indiana: Guidelines and Calculations

How child support is calculated in Indiana using the Income Shares Model. Learn about parenting time credits, the 52-overnight threshold, modification rules, and enforcement.

14 min read · Updated April 2026
Support

Imputed Income in Child Support: When Courts Assign Earnings

How courts impute income for child support when a parent is voluntarily unemployed or underemployed — factors, exceptions, vocational evaluations, and how to respond.

10 min read · Updated April 2026
Support

Child Support in Tennessee: Guidelines and Calculations

How child support is calculated in Tennessee using the Income Shares Model. Learn about parenting time adjustments, the 92-day threshold, modification rules, and enforcement.

13 min read · Updated April 2026
Support

Child Support in Massachusetts: Guidelines and Calculations

How child support is calculated in Massachusetts under the 2025 guidelines. Learn about income shares, the worksheet, deviation factors, college costs, and modification.

14 min read · Updated April 2026
Support

Child Support Across State Lines: UIFSA Explained

How child support works when parents live in different states. Learn about UIFSA, continuing exclusive jurisdiction, interstate enforcement, and modification rules.

14 min read · Updated April 2026
Support

Child Support in Arizona: Guidelines and Calculations

How child support is calculated in Arizona using the Income Shares Model. Learn about the 2022 guidelines, parenting time adjustments, older child increases, modification, and enforcement.

13 min read · Updated April 2026
Support

Child Support in Maryland: Guidelines and Calculations

A detailed guide to Maryland's child support guidelines under Md. Code, Family Law Section 12-204, covering the income shares model, shared custody adjustments, the multifamily adjustment, deviation factors, voluntary impoverishment, and enforcement.

12 min read · Updated April 2026
Support

Child Support in Washington: Guidelines and Calculations

How child support is calculated in Washington State using the Income Shares Model. Learn about the 2026 economic table expansion, deductions, modification, and enforcement.

13 min read · Updated April 2026
Support

Child Support in Virginia: Guidelines and Calculations

How child support is calculated in Virginia using the Income Shares Model. Learn about the 2025 guideline updates, shared custody formulas, modification, and enforcement.

13 min read · Updated March 2026
Support

Child Support in New Jersey: Guidelines and Calculations

How child support is calculated in New Jersey using the Income Shares Model. Learn about guidelines, worksheets, modification, college costs, and enforcement.

13 min read · Updated March 2026
Support

Spousal Support and Alimony: Complete Guide

Learn how alimony and spousal support work, including types of awards, how courts calculate payments, tax rules, and modification options. Free 2026 guide.

17 min read · Updated March 2026
Support

Child Support for Self-Employed Parents in California

Learn how California courts calculate child support when a parent is self-employed, including income determination, business expense scrutiny, lifestyle analysis, imputed income, Ostler-Smith orders, and discovery tools.

10 min read · Updated March 2026
Support

How California Calculates Spousal Support

Learn how spousal support is calculated in California, including temporary support formulas, permanent support factors under FC 4320, the 10-year marriage rule, and how cohabitation affects alimony.

10 min read · Updated March 2026
Support

Florida Alimony Law: Types, Duration, and Recent Changes

Understand Florida's 2023 alimony reform (SB 1416), the elimination of permanent alimony, the four remaining types, duration caps, and how the new law affects existing and future cases.

10 min read · Updated March 2026
Support

Florida Child Support Guidelines Explained

A detailed guide to Florida's child support guidelines under FL Stat 61.30, covering the income shares model, net income calculation, time-sharing adjustments, add-ons, deviations, and imputed income.

10 min read · Updated March 2026
Support

Alimony in Georgia: Types, Factors, and Duration

Understand how alimony works in Georgia, including temporary, permanent, and rehabilitative alimony, the factors courts consider, the adultery bar, and modification rules.

10 min read · Updated March 2026
Support

Understanding the Georgia Child Support Worksheet

A detailed guide to Georgia's child support worksheet under OCGA 19-6-15, including the income shares model, Schedule A vs. Schedule B, adjustments, and deviation factors.

10 min read · Updated March 2026
Support

Imputing Income for Child Support in Illinois

Understand when and how Illinois courts impute income for child support, including voluntary unemployment, underemployment, and the evidence courts consider.

9 min read · Updated March 2026
Support

How Illinois Calculates Spousal Maintenance

Understand Illinois spousal maintenance under 750 ILCS 5/504, including the guideline formula, duration multipliers, deviation factors, and tax treatment after the TCJA.

9 min read · Updated March 2026
Support

How Michigan Calculates Child Support

Understand Michigan's child support formula, including how net income is calculated, how overnights affect support, add-ons for medical and childcare costs, deviation factors, and the Friend of the Court's role.

9 min read · Updated March 2026
Support

Spousal Support in Michigan: Factors and Duration

Understand how Michigan courts determine spousal support (alimony), including the Olson factors, types of spousal support, duration considerations, modification, the impact of fault and cohabitation, and current tax treatment.

10 min read · Updated March 2026
Support

North Carolina Child Support Guidelines Explained

Understand how North Carolina calculates child support using the income shares model under NCGS 50-13.4. Learn about the Guidelines worksheets, gross income, adjustments for health insurance and childcare, shared custody overnights, deviation factors, and imputed income.

10 min read · Updated March 2026
Support

Post-Separation Support and Alimony in North Carolina

Understand the difference between post-separation support and alimony in North Carolina, including the 16 statutory factors, how marital misconduct affects awards, and when alimony can be modified.

9 min read · Updated March 2026
Support

Child Support Until 21 in New York

Understand New York's unique rule requiring child support until age 21, including the CSSA formula, emancipation exceptions, college expenses, and how support changes at 18 vs. 21.

9 min read · Updated March 2026
Support

New York's Spousal Maintenance Formula

A detailed guide to New York's spousal maintenance formula under DRL 236(B)(6), including the 2015 reform, income cap, duration guidelines, temporary vs post-divorce maintenance, and deviation factors.

10 min read · Updated March 2026
Support

Alimony Duration and Types in Pennsylvania

Understand Pennsylvania alimony law, including the 17 statutory factors under 23 Pa.C.S. 3701, APL vs. alimony, duration guidelines, and grounds for modification.

10 min read · Updated March 2026
Support

Pennsylvania Child Support Guidelines Explained

Understand Pennsylvania child support under Pa.R.C.P. 1910.16, including the income shares model, support tables, adjustments for healthcare and childcare, high-income cases, and modification rules.

10 min read · Updated March 2026
Support

How to Modify Child Support in Texas

Learn how to modify a child support order in Texas. Understand the material and substantial change standard, the 3-year rule, how to file, and whether to use the AG's office or a private attorney.

9 min read · Updated March 2026
Support

Spousal Maintenance Eligibility in Texas

Learn about spousal maintenance eligibility in Texas, including the strict requirements under TFC 8.051-8.055, the $5,000/month cap, duration limits, the distinction between court-ordered maintenance and contractual alimony, and modification rules.

9 min read · Updated March 2026
Support

How Ohio Calculates Child Support

A detailed guide to Ohio's child support calculation, including the income shares model, the basic child support schedule, parenting time adjustments, and deviation factors.

10 min read · Updated March 2026
Support

Spousal Support Factors in Ohio

Learn how Ohio courts determine spousal support, including the 14 statutory factors under ORC 3105.18, types of awards, modification, and what to expect.

10 min read · Updated March 2026
Support

Alimony and Spousal Support: The Complete Guide

Everything you need to know about alimony — types, how it's calculated, duration, state laws, tax rules, and how to protect yourself in negotiations.

14 min read · Updated March 2026
Support

Child Support Arrears: Consequences and Solutions

What happens when you fall behind on child support — enforcement actions, penalties, how to resolve arrears, and options for getting back on track.

9 min read · Updated March 2026
Support

Child Support and College Expenses

Can courts order parents to pay for college after divorce? Which states require it, how costs are divided, and how to plan for your child's education.

8 min read · Updated March 2026
Support

How Long Does Alimony Last

How courts determine alimony duration — by marriage length, state guidelines, types of alimony, and when payments end.

8 min read · Updated March 2026
Support

Child Support for Special Needs Children

How child support works for children with special needs — extended support obligations, additional expenses, modification options, and protecting government benefits.

9 min read · Updated March 2026
Support

Child Support and Taxes

How child support affects your taxes — is it taxable or deductible, who claims the children, dependency exemptions, and common tax mistakes to avoid.

7 min read · Updated March 2026
Support

How Remarriage Affects Alimony

What happens to alimony when you or your ex remarries — automatic termination, cohabitation rules, the impact on the payer, and state-by-state differences.

8 min read · Updated March 2026
Support

Self-Employment Income and Child Support

How courts handle self-employment income in child support cases — calculating income, business deductions, imputed income, and preventing manipulation.

9 min read · Updated March 2026
Support

Alaska Child Support Guidelines

How Alaska calculates child support — the percentage of income model, deductions, modifications, and enforcement.

8 min read · Updated March 2026
Support

How Arkansas Calculates Child Support

Arkansas child support guidelines — the income shares model, calculation charts, deviations, and how to estimate your support obligation.

8 min read · Updated March 2026
Support

Colorado Spousal Maintenance Guidelines

How Colorado calculates spousal maintenance — the advisory guidelines formula, duration, factors courts consider, and modification.

9 min read · Updated March 2026
Support

Connecticut Alimony: Types, Duration, and Factors

How Connecticut courts determine alimony — types of alimony, factors considered, duration guidelines, and recent reforms.

8 min read · Updated March 2026
Support

Idaho Child Support Guidelines

How Idaho calculates child support — the income shares model, guidelines, deviations, and enforcement.

8 min read · Updated March 2026
Support

Iowa Child Support Guidelines

How Iowa calculates child support — the income shares model, guidelines, worksheets, and what affects your support amount.

8 min read · Updated March 2026
Support

Louisiana Child Support Guidelines

A detailed guide to Louisiana's child support guidelines under LSA-R.S. 9:315, covering the income shares model, gross income, the guidelines schedule, healthcare and childcare add-ons, shared custody adjustments, deviation factors, and extraordinary expenses.

10 min read · Updated March 2026
Support

Maryland Alimony: Factors and Types

A detailed guide to alimony in Maryland, including the types of alimony available, the 12 statutory factors courts consider, duration guidelines, modification rules, cohabitation impact, and recent trends in alimony awards.

10 min read · Updated March 2026
Support

Massachusetts Child Support Guidelines

A comprehensive guide to Massachusetts child support guidelines, covering the income shares model, gross income calculation, the guidelines worksheet, presumptive amounts, deviation factors, healthcare and childcare costs, parenting time adjustments, college support obligations, and how to modify an existing order.

10 min read · Updated March 2026
Support

Kansas Child Support Guidelines

How Kansas calculates child support — the income shares model, worksheets, adjustments, and deviation factors.

8 min read · Updated March 2026
Support

Mississippi Child Support Guidelines

A detailed guide to Mississippi's child support guidelines, covering the percentage of income model, statutory percentages, adjusted gross income, deviation factors, healthcare obligations, and modification.

10 min read · Updated March 2026
Support

Nebraska Child Support Guidelines

Understand how Nebraska calculates child support using the income shares model, including income calculation, the support worksheet, health insurance, childcare, deviation criteria, and modification rules.

8 min read · Updated March 2026
Support

New Jersey Alimony: Reform and Types

Understand New Jersey's 2014 alimony reform, the four types of alimony (open durational, limited duration, rehabilitative, and reimbursement), the 14 statutory factors, and how retirement and cohabitation affect alimony obligations.

9 min read · Updated March 2026
Support

North Dakota Child Support Guidelines

A detailed guide to North Dakota's child support guidelines under NDCC 14-09, covering the income shares model, net income calculation, guidelines schedule, healthcare and childcare add-ons, multi-family adjustments, deviation criteria, and modification.

8 min read · Updated March 2026
Support

Oklahoma Child Support Guidelines

A detailed guide to Oklahoma's child support guidelines under 43 OS Section 118, covering the income shares model, gross income calculation, guidelines schedule, healthcare and childcare add-ons, shared custody adjustments, deviation factors, self-employment income, and modification.

8 min read · Updated March 2026
Support

Rhode Island Child Support Guidelines

Understand how Rhode Island calculates child support using the income shares model, including gross income definitions, the guidelines schedule, healthcare and childcare costs, shared placement, deviation factors, and modification rules.

8 min read · Updated March 2026
Support

South Dakota Child Support Guidelines

A detailed guide to South Dakota child support calculations using the income shares model, including net income definitions, the guidelines schedule, healthcare and childcare adjustments, shared custody modifications, deviation factors, and how to modify a support order under SDCL Chapter 25-7.

8 min read · Updated March 2026

Related Topics

Bookmark This Resource

Save this page and come back when you need it — all our guides are free and always available.