Pennsylvania uses a formula based on both parents' income, not a flat rate

Pennsylvania does not have a single child support amount that applies to everyone. Instead, the state uses the Income Shares Model, which calculates support based on what both parents earn, how much time each parent spends with the child, and the number of children involved. The formula produces a number that represents the total child support obligation, which is then divided between the parents based on their income percentages.

The calculation starts with each parent's net monthly income — gross income minus taxes, Social Security, and certain other deductions. Pennsylvania then applies a percentage based on how many children need support. For one child, the combined parental income up to a certain threshold is subject to a percentage obligation. For two children, the percentage is higher; for three children, higher still. These percentages change periodically as the state updates its guidelines.

The threshold itself — called the income cap — also changes. As of recent years, Pennsylvania caps the income subject to the formula at a specific amount, though either parent can request that income above the cap be included if circumstances warrant it. A judge has discretion to deviate from the formula if the guideline amount would be unjust or inappropriate given the specific family situation.

Key Takeaways

  • Child support in Pennsylvania is calculated using the Income Shares Model, which divides a percentage of combined parental income based on each parent's earnings.
  • The percentage obligation varies by the number of children: one child carries a different percentage than two or three children.
  • Only income up to the state's current income cap is subject to the formula, though a judge can include higher income if requested.
  • The actual dollar amount one parent pays depends on their share of the combined income and custody time, so two families with the same number of children will have different support amounts.
  • Pennsylvania updates its guideline percentages periodically, so the formula that applied last year may not apply this year.

What counts as income for the calculation

Pennsylvania's definition of income is broad. It includes wages, salary, bonuses, commissions, self-employment income, rental income, Social Security benefits (in certain cases), unemployment benefits, workers' compensation, disability payments, and income from pensions or retirement accounts. It also includes income from new jobs, even if the parent recently started working.

The state does allow certain deductions before the percentage is applied. These include federal and state income taxes, Social Security taxes, health insurance premiums for the child, and court-ordered support for other children. Some parents also deduct the cost of childcare needed to allow them to work, though this deduction is applied differently depending on custody arrangements.

If a parent is intentionally underemployed — earning less than they could — a judge may impute income, meaning the court assigns an income figure based on what the parent could reasonably earn. This prevents a parent from reducing support by deliberately working part-time or taking a lower-paying job.

How custody time affects the support amount

The percentage of time each parent spends with the child directly affects the calculation. If one parent has the child 90 percent of the time and the other 10 percent, the support obligation differs from a 50-50 split. Pennsylvania recognizes several custody arrangements: primary custody (one parent has the child most of the time), shared custody (roughly equal time), and partial custody (the non-custodial parent has the child a set number of days per month).

The state defines shared custody as each parent having the child at least 40 percent of the time. When this threshold is met, the formula adjusts so that both parents' incomes are treated differently than in a primary custody case. The parent with lower income typically pays less support, or may receive support, depending on the income gap.

Custody time is measured in overnights per year or days per month, depending on the court's preference. If parents cannot agree on a custody schedule, the court will establish one, and that schedule becomes the basis for the support calculation.

The income cap and high-income cases

Pennsylvania sets an income cap — a maximum amount of combined parental income subject to the guideline percentage. Income above this cap is not automatically included in the formula. However, either parent can request that the court consider income above the cap when deciding the support amount.

When income exceeds the cap, the judge has discretion to apply the guideline percentage to the excess income, apply a lower percentage, or disregard it entirely. The judge must consider factors such as the standard of living the child enjoyed before the separation, the financial resources of both parents, and the child's actual needs. A child whose parents earn $500,000 combined may need more support than the guideline formula produces, or the judge may find the guideline amount sufficient.

The income cap itself is adjusted annually by the state, so the threshold that applied last year may be different this year. Both parents should verify the current cap with the court or a family law attorney before calculating an estimate.

Examples of how the formula works

Suppose Parent A earns $3,000 per month net and Parent B earns $2,000 per month net. Combined, they earn $5,000. They have one child and share custody roughly equally (each parent has the child about 50 percent of the time). Pennsylvania's guideline for one child might be 16 percent of combined income (this percentage varies and should be verified with current state guidelines). Sixteen percent of $5,000 is $800.

Parent A's share of the combined income is 60 percent ($3,000 of $5,000). Parent B's share is 40 percent ($2,000 of $5,000). In a shared custody case, the parent with higher income typically pays the difference between their share of the guideline amount and what they would receive if the obligation were split equally. The exact calculation depends on the custody percentage and whether either parent receives a credit for overnight expenses.

Now suppose the same two parents have two children instead of one. The guideline percentage for two children is higher — perhaps 25 percent. Twenty-five percent of $5,000 is $1,250. The same income-share logic applies, but the total obligation is larger because more children are involved.

Deviations from the guideline amount

A judge is not required to order exactly what the formula produces. Pennsylvania law allows the court to deviate from the guideline if the amount would be unjust or inappropriate. Common reasons for deviation include a parent's extraordinary expenses (such as medical costs for a child with special needs), the child's actual living expenses, the financial resources available to each parent beyond income, and the standard of living the child had before the parents separated.

A parent requesting a deviation must present evidence to the court explaining why the guideline amount is unfair. Simply disagreeing with the formula is not enough; the parent must show specific circumstances that make the guideline amount unjust. If the court deviates, it must state its reasons in writing.

When and how the amount changes

A child support order remains in effect until the child turns 18, graduates high school (whichever is later), or reaches age 19 if still in high school. The amount can change before that if either parent's income changes significantly, custody arrangements change, or the state updates its guideline percentages.

Either parent can request a modification if income has increased or decreased by a certain percentage (usually 10 percent or more) or if circumstances have changed substantially. The requesting parent must file a petition with the court and provide evidence of the income change. The court will recalculate using current income and current guideline percentages.

Pennsylvania also reviews child support orders periodically — typically every three years — to ensure they still reflect current income and guideline percentages. If a review shows the amount should change by more than a small threshold, the court may adjust the order automatically or notify the parents that a modification is available.

Frequently Asked Questions

Is there a minimum child support amount in Pennsylvania?

Pennsylvania does not set a statewide minimum, but individual counties or judges may have local practices. Generally, if the combined parental income is very low, the guideline formula may produce a small amount or even zero. A judge can still order support if the non-custodial parent has income, but the amount reflects what the formula calculates.

Does child support stop automatically when the child turns 18?

Support continues until the child turns 19 if still in high school, or until high school graduation, whichever is later. After that, support ends unless the child is disabled or the parents agreed to extend it. The paying parent does not need to file anything; support stops by operation of law on the end date stated in the order.

What if one parent is self-employed or has irregular income?

Self-employment income is included in the calculation, but the court may average income over a period of time (often one to three years) to account for fluctuations. The paying parent must provide tax returns, profit-and-loss statements, or other documentation to prove actual income. If income is genuinely unpredictable, the judge may set a base amount and adjust it periodically as actual income becomes known.

Can child support be modified if a parent loses their job?

Yes, but the parent must request a modification and prove the job loss was not voluntary. If a parent quit to avoid paying support, the court may impute income based on what they could earn. If the job loss was involuntary, the court will recalculate based on current income (which may be unemployment benefits or a new lower-paying job) and may reduce or suspend support temporarily.

How do I find out what the current guideline percentages are?

Pennsylvania publishes updated child support guidelines annually. You can find them through the Pennsylvania Court Rules website, your county's domestic relations office, or by asking a family law attorney. The percentages and income cap change, so using outdated figures will produce an inaccurate estimate.