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Alimony guide

What is alimony, how is it calculated, and what changed in 2019?

What is alimony (spousal support)?

Alimony — also called spousal support or spousal maintenance — is a court-ordered payment from one spouse to the other after a divorce or legal separation. Its purpose is to limit the financial unfairness that results when one spouse earns significantly more than the other or when one spouse sacrificed career advancement during the marriage to raise children or support the other's career.

Alimony is distinct from child support. Child support is paid for the benefit of a minor child and is calculated using different formulas focused on the child's needs and each parent's ability to pay. Alimony is paid directly to the former spouse and relates to the economic partnership of the marriage itself.

Alimony vs. child support: key differences

• Purpose: Child support covers the direct costs of raising a child (housing, food, clothing, healthcare, education). Alimony compensates a spouse for lost earning capacity and maintains a comparable standard of living post-divorce.
• Tax treatment (post-2019): Child support has always been tax-neutral — non-deductible for the payor, not taxable income for the recipient. Alimony under the old law (pre-2019) was deductible for the payor and taxable for the recipient. Under the Tax Cuts and Jobs Act of 2017, for divorce agreements executed after December 31, 2018, alimony is no longer deductible and is no longer taxable income.
• Duration: Child support ends when the child reaches the age of majority (typically 18–21 depending on state). Alimony duration depends on the marriage length, the receiving spouse's ability to become self-supporting, and judicial discretion.
• Modifiability: Both can generally be modified upon a substantial change in circumstances (income change, remarriage, cohabitation). However, the thresholds and procedures vary by state.

How marriage length affects alimony duration

Marriage length is one of the most influential factors in both the amount and the duration of alimony. Courts typically recognise three categories:

• Short-term marriages (under 5 years): Alimony, if awarded at all, is typically rehabilitative — intended to support the lower-earning spouse only while they retrain or re-enter the workforce. Duration is usually less than half the marriage length.
• Medium-term marriages (5–20 years): Courts commonly use a rough guideline of half the marriage length as a starting point for support duration. A 10-year marriage might generate 5 years of support; a 15-year marriage, 7–8 years.
• Long-term marriages (20+ years): There is a meaningful risk of permanent or indefinite alimony in many states, particularly where one spouse was a full-time homemaker, or where the age or health of the recipient spouse makes self-sufficiency unrealistic. Some states have moved away from permanent alimony; others (e.g., Massachusetts before 2011, Florida before 2023) traditionally awarded it routinely.

The 2019 tax law change: what it means for negotiations

Before December 31, 2018, the federal tax treatment of alimony created a negotiation incentive: the payor (typically in a higher tax bracket) could deduct payments, reducing their after-tax cost. The recipient (in a lower bracket) paid tax, but at a lower rate. This meant $1 of alimony cost less than $1 net to the payor, while providing the recipient with nearly $1 in after-tax value — a tax efficiency benefit.

Since the TCJA change, alimony is taxed the same as child support — no deduction for the payor, no income for the recipient. The practical effect: payments are more expensive in after-tax terms for the payor, because they pay out of post-tax income. This has shifted alimony negotiations: payors now push harder for lower amounts or lump-sum settlements, and the previous cross-bracket arbitrage no longer applies.

Factors courts consider beyond income

While income and marriage length drive most general formula estimates, courts consider many additional factors when setting actual alimony:

• The standard of living established during the marriage
• Each spouse's age, health, and employability
• The receiving spouse's contributions as a homemaker or caregiver
• Whether one spouse supported the other's education or career
• The awarding of marital property in the overall settlement
• Each spouse's existing debts and financial obligations
• Contributions to the other's earning capacity (e.g., putting a spouse through medical school)
• The behaviour of the parties (some states consider fault)

State-by-state variation

Alimony law is governed entirely at the state level; there is no federal standard. Key contrasts:

• California uses a different formula as a starting point: 40% of the payor's net income minus 50% of the recipient's net income. California also refers to alimony as “spousal support.”
• New York has a statutory formula for temporary support (during proceedings) but exercise of judicial discretion is broader for post-divorce maintenance.
• Texas is famously restrictive — “contractual alimony” must be agreed voluntarily; court-ordered “spousal maintenance” requires meeting strict criteria including marriage length of 10+ years.
• Florida eliminated permanent alimony in 2023 and now requires a formula-based approach tied to marriage length and income.

The formula used in this calculator (30% of higher income minus 20% of lower income) is a general approximation and does not represent any specific state's law.