How Pennsylvania Calculates Child Support: What Goes Into the Number

August 3, 2026

Pennsylvania calculates child support using an income shares model, which means the number on your support order is built from both parents’ combined net income, not just the paying parent’s paycheck. Our Pennsylvania child support attorneys walk clients through this calculation constantly, because the figure a parent receives often looks confusing until you can see what actually went into it. This article breaks down the mechanics behind that number: how combined income is determined, how the guideline table turns income into a starting figure, how custody time adjusts it, and where a court can deviate from the guideline amount. None of this is a substitute for a calculation specific to your income and custody arrangement, but it will help you understand what you are looking at.

Where the Number Starts: Combined Net Monthly Income

Pennsylvania’s guidelines add both parents’ monthly net incomes together to reach a single combined figure. ^[1] That combined number, matched against the number of children, is what determines the starting point on the state’s guideline schedule.

What Counts as Income

Pennsylvania defines income broadly for support purposes. It generally includes:

Wages, salaries, and commissions
Bonuses
Self-employment income
Rental income
Interest and dividends
Social Security, unemployment compensation, and workers’ compensation
Income from substantially any other source

From gross income, certain items are deducted to reach net income, most notably federal, state, and local taxes, F.I.C.A. and mandatory retirement contributions, and support already being paid for other children or a former spouse who are not part of the current case.

How the Guideline Table Turns Income Into a Number

Once combined net monthly income is known, it is matched against the number of children on the Basic Child Support Schedule to produce a presumptive basic child support obligation. ^[2] Each parent’s percentage share of the combined income is then applied to that figure, so the parent earning the larger share of the household’s total income carries the larger share of the obligation. For families with combined net monthly income above the schedule’s upper limit of $30,000, a separate high-income methodology applies rather than a direct table lookup, and this is a situation where getting an attorney involved early is particularly worthwhile.

The 2026 Guidelines Update

Pennsylvania is required to review its support guidelines at least every four years, and an updated Basic Child Support Schedule took effect January 1, 2026. Basic support obligations increased by roughly 3 to 10 percent across most income levels under the new schedule, and the self-support reserve, the minimum monthly income a paying parent is allowed to keep for their own basic needs, was raised from $1,063 to $1,255. The update also added unreimbursed psychiatric, psychological, and orthodontic expenses to the list of medical costs treated as coverable under the guidelines. An existing order does not change automatically because of this update. A parent has to file a petition to modify, and any change applies only from the date that petition is filed, not retroactively to January 1, 2026.

How Custody Time Changes the Number

The percentage of overnights each parent has with the child directly affects the calculation. ^[3] When the parent who would otherwise pay support has the child for at least 40 percent of overnights in a year, roughly 146 nights, the guidelines assume that parent is already directly covering more of the child’s day-to-day costs during that time. That recognition reduces the paying parent’s percentage share of the basic obligation, with the reduction growing as their overnight share grows, up to a maximum adjustment at a genuinely equal, 50/50 schedule. Below the 40 percent threshold, this adjustment does not apply and the standard income-shares math controls.

What Gets Added on Top of the Basic Number

The Basic Child Support Schedule only produces the core support figure. Certain additional child-related expenses are layered on top and allocated between the parents in proportion to their income shares, including:

Health insurance premiums paid for the child
Work or education-related childcare costs
Unreimbursed medical, dental, and orthodontic expenses, along with psychiatric and psychological expenses under the 2026 update

These additions are why two families with the same combined income and the same number of children can still end up with meaningfully different final support figures.

When a Court Deviates From the Guideline Number

The guideline amount is presumed correct, but it is a presumption, not an absolute. A court can adjust the number up or down after considering: ^[4]

Unusual needs and unusual fixed obligations
A party’s other support obligations
Other income in the household
The child’s age
The parties’ relative assets and liabilities
Medical expenses not covered by insurance
The parties’ and the child’s standard of living
Other relevant and appropriate factors, including the child’s best interest

A deviation applies to the amount or duration of the support obligation itself, not to how a party’s income is calculated in the first place.

When Reported Income Isn’t the Whole Story

Self-employment, commission-based pay, and irregular income create real complications, because the number on a tax return is not always the number a court will use. A court can look past what a parent reports and impute income based on that parent’s earning capacity if it finds the parent is voluntarily underemployed or structuring their finances to minimize apparent income. This is one of the areas where a guideline calculation done without careful attention to the underlying financial picture can produce a number that does not reflect what a parent can actually pay, or is actually earning.

Frequently Asked Questions

How is child support calculated in Pennsylvania using the income shares model?

Both parents’ net monthly incomes are added together and matched against the number of children on the state’s guideline schedule to produce a basic support obligation. Each parent then owes a share of that obligation proportional to their share of the combined income, before custody time and additional expenses are factored in.

What income counts toward child support in Pennsylvania?

Pennsylvania’s definition of income is broad and includes wages, salaries, commissions, bonuses, self-employment income, rental income, interest and dividends, and benefits such as Social Security or unemployment compensation. Certain deductions, like taxes and mandatory retirement contributions, are subtracted to reach net income.

How does the number of children affect child support in Pennsylvania?

The guideline schedule is structured around both combined income and the number of children, so the basic obligation increases as the number of children covered by the order increases, though not in a simple one-to-one multiple.

What deviation factors can change a Pennsylvania child support calculation?

A court can deviate from the guideline amount based on factors such as unusual needs or fixed obligations, other support obligations either party carries, other household income, the child’s age, the parties’ assets and liabilities, uninsured medical expenses, and the family’s standard of living, among other relevant considerations.

Talk to a Lancaster County Child Support Attorney About Your Number

A guideline calculation involves more moving pieces than most parents expect, and small differences in income, custody time, or deductions can meaningfully change the outcome. Lancaster Law Group can review your specific income and custody situation and tell you what the number should actually reflect.

Call us at 717-358-0600 or schedule a consultation online to go through your numbers with an attorney. Meet the attorneys who will handle your case, or see the Pennsylvania communities we serve from our office in Downtown Lancaster.