Maintenance (Alimony) Under Current Illinois Guidelines

Maintenance — what Illinois used to call alimony, and what the federal tax code no longer rewards — is governed by section 504 of the Illinois Marriage and Dissolution of Marriage Act. The headline is that there’s a formula. The reality is that the formula is the starting point, not the ending point, in most cases that actually get fought.

The guideline formula

For couples with a combined gross annual income under $500,000 and no obligation under a prior maintenance order:

• Amount = (33.3% × payor’s net annual income) − (25% × payee’s net annual income).
• Cap — the combined amount must not result in the payee receiving more than 40% of the parties’ combined net income.
• Duration — calculated by multiplying the length of the marriage (in years) by a statutory percentage that scales from 20% for short marriages to 100% (indefinite) for marriages of 20 or more years.

Net income for this calculation has its own statutory definition that differs from federal taxable income. Pre-tax retirement contributions, certain health insurance premiums, and prior-order child support are treated specifically.

When the guideline doesn’t apply

The court is not required to follow the formula when combined gross income exceeds $500,000, or when one party has a prior maintenance obligation. In those cases the court determines a reasonable amount and duration considering the section 504 factors.

Deviations from the guideline — even under $500,000

Even when the guideline applies, the court may deviate based on the section 504 factors:

• Income and property of each party, including marital and non-marital allocations from the dissolution itself.
• Needs of each party.
• Realistic earning capacity — current and future, including the effect of foregone career opportunities during the marriage.
• Impairments to earning capacity — domestic responsibilities that delayed education or training; effect of parenting on remaining earning years.
• Time necessary to acquire education or training.
• Standard of living established during the marriage.
• Duration of the marriage.
• Age, health, and station of each party.
• All sources of income including investment income and benefits.
• Tax consequences of the property division on each party.
• Contributions by either party to the education or career of the other.
• Any valid agreement between the parties.
• Any other factor the court expressly finds to be just and equitable.

Modification and termination

Maintenance can be modified on a showing of a substantial change in circumstances — which is the same standard that applies to child support modifications. Common modification triggers:

• Significant change in income (job loss, retirement, promotion).
• Cohabitation by the recipient with another adult on a continuing conjugal basis (terminates maintenance entirely under section 510(c)).
• Remarriage of the recipient (also terminates maintenance entirely).
• Death of either party (terminates maintenance unless the judgment expressly survives).

Where most maintenance fights actually happen

In most contested cases, the dispute is not over the formula — it’s over the inputs to the formula, or over deviation. Common battlegrounds:

• Imputing income to an unemployed or underemployed party.
• Self-employment income — what counts, what gets added back from depreciation and personal-use expenses.
• Voluntary income reduction — taking a lower-paying job before filing.
• Duration above 20 years — when does "indefinite" actually mean indefinite, and when does it get reviewed.
• Asset-rich, income-low situations — what happens when one party has significant non-income-producing property.

VF Law works through both sides of this — establishing income (and imputing it where warranted) and defending against improper imputation in equal measure. The formula is two lines of statute. The case is everything around it.