How is Child Support Calculated in Tennessee?

Tennessee child support is based on both parents' incomes combined. The state uses the Income Shares Model — it looks at what both parents earn together, finds a baseline obligation on a state schedule, and then splits that obligation proportionally based on each parent's share of the combined income. The non-primary residential parent's share is paid to the primary residential parent. Parenting time can significantly affect the final number.

The Income Shares Model: the big picture

Tennessee's child support system is governed by Rule 1240-02-04 of the Tennessee Child Support Guidelines, which courts and administrators are required to follow. The guidelines treat child support as a shared financial responsibility — both parents contribute in proportion to what they earn.

The calculation runs in three main steps. First, both parents' gross monthly incomes are determined and combined. Second, that combined figure is looked up on the Basic Child Support Obligation (BCSO) schedule to find the total monthly obligation for the number of children involved. Third, each parent's share of the combined income is calculated, and that percentage determines what each parent owes toward the total obligation. The parent who does not have primary residential custody pays their proportional share directly.

Parenting time matters here too. When the non-primary residential parent has the child for a significant portion of the year, an Alternative Residential Schedule (ARS) adjustment may reduce their obligation to reflect the direct costs they bear during their parenting time.

How Tennessee defines gross income

Tennessee's guidelines define gross income broadly. For most parents, it means every dollar of income before taxes and deductions. The list of what counts is extensive.

Income type	Included?
Wages, salaries, commissions, bonuses, tips	Yes
Self-employment income	Yes — gross revenue minus ordinary/necessary business expenses
Overtime and second-job earnings	Yes
Rental income	Yes — gross rent minus ordinary/necessary expenses
Dividend, interest, and investment income	Yes
Pension, retirement, and disability benefits	Yes
Social Security benefits (including child's derivative benefit)	Yes, with specific treatment for derivative benefits paid on behalf of the child
Workers' compensation and unemployment benefits	Yes
SNAP, Medicaid, TANF, and similar means-tested benefits	Excluded — not counted as income

How the Basic Child Support Obligation schedule works

Once both parents' gross monthly incomes are determined and combined, that combined monthly figure is looked up on the BCSO schedule. The schedule lists dollar obligations for different income levels and numbers of children — one through six or more.

Each parent then pays their proportional share. If Parent A earns 60% of the combined income, Parent A is responsible for 60% of the BCSO. The non-primary residential parent's share flows to the primary residential parent as the monthly payment. The primary residential parent's share is considered as already being spent directly on the child through the household.

Tennessee's BCSO schedule covers a wide range of combined monthly incomes. For income levels above the schedule's cap, courts have discretion to set an amount based on the child's needs and the established standard of living. For very low combined incomes, a minimum order may apply — typically $100 per month — to ensure that a support obligation exists on the record even when resources are extremely limited.

How parenting time affects child support: the ARS adjustment

This is where Tennessee's calculation gets more involved — and where parenting time has real financial consequences.

Tennessee distinguishes between two situations based on how many days per year the Alternative Residential Parent (ARP) — the parent who does not have primary custody — has the child. The ARP is the parent who pays support.

ARP parenting days per year	How it's treated
Fewer than 92 days	Standard calculation — no ARS adjustment. The ARP pays their full proportional share of the BCSO plus applicable add-ons.
92 to 182 days	ARS adjustment applies. A credit is calculated using a formula that accounts for the portion of time the ARP has the child. This credit reduces the ARP's obligation to reflect direct costs borne during parenting time.
183 days or more (50/50 or more)	Shared parenting calculation — a different formula applies that accounts for both parents bearing roughly equal direct costs. The parent with the higher income generally pays the lower earner, but the amount is significantly reduced compared to a standard order.

The ARS credit formula is designed to recognize that a parent spending significant time with their child is bearing real costs — food, transportation, clothing, activities — during that time. Simply paying the full guideline obligation would result in double-counting those expenses. The credit prevents that.

The ARS adjustment is a formula-based calculation, not a negotiation. It applies automatically when the parenting schedule meets the threshold. Courts may also consider parenting time as a deviation factor when parenting arrangements fall outside the standard schedule in unusual ways.

Worked example — two incomes, one child, standard parenting time

Add-ons: health insurance and childcare

The BCSO from the schedule is only the starting point. Tennessee's guidelines require two additional cost categories to be added on top of the base obligation and split proportionally between both parents.

The first add-on is the cost of the children's health insurance coverage. If one parent provides insurance that covers the children, the children's share of that premium is calculated and each parent pays their proportional share of it. The second add-on is work-related childcare costs — daycare, after-school programs, or other care expenses that allow a parent to maintain employment. These too are added to the BCSO and split proportionally.

Extraordinary uninsured medical expenses — costs that arise outside normal routine care — are also typically split proportionally when they occur, though the exact mechanism may be addressed in the parenting plan rather than the regular support order.

When courts may deviate from the guidelines

Tennessee courts treat the guideline amount as the presumptive correct figure. A deviation — either upward or downward — requires a written finding that the guideline amount would be unjust or inappropriate in a particular case.

Factors courts may consider for a deviation include the child's special educational or medical needs, a significant disparity in the standard of living between the two households, a parent's extraordinarily high income where the guideline amount would produce far more than the child needs, travel costs associated with extended parenting time, and the existence of other minor children a parent is legally obligated to support. The burden is on the parent requesting a deviation to show why the guideline amount doesn't serve the child's best interest.

If you're working through Tennessee divorce finances more broadly, the Tennessee divorce finances overview covers property division, spousal support, and retirement accounts. We also have a separate guide on how spousal support is calculated in Tennessee — including the four types of support and the 12 statutory factors courts weigh.

Common questions about Tennessee child support

When does Tennessee child support end? Child support generally ends when the child turns 18. If the child is still enrolled in secondary school at 18, support may continue until graduation or the child's 19th birthday, whichever comes first. Courts may consider extending support for a child who is severely disabled and unable to be self-supporting, depending on documented circumstances. The parenting plan may also include agreements to contribute toward post-secondary education, though courts do not routinely order college support in Tennessee. For a broader look at how long support typically runs, see our guide on how long child support lasts.

Can Tennessee child support be modified? Yes. Either parent may petition for a modification if there has been a substantial and material change in circumstances since the last order was set. Tennessee courts generally apply the "15% test" — if recalculating under current guidelines would produce an amount that differs from the existing order by 15% or more, that typically qualifies as a substantial change sufficient to support a modification request. Either parent may also request a review every three years without needing to show a changed circumstance.

What if a parent is self-employed? Self-employment income is included in gross income under Tennessee's guidelines. Courts look at gross revenue minus ordinary and necessary business expenses to arrive at the income available for support. Personal expenses run through a business, lifestyle expenditures, and excessive depreciation may be scrutinized and added back. Courts can review tax returns, Schedule C filings, and bank statements when self-employment income is in dispute.

Does the ARS adjustment apply automatically? Yes, once the parenting schedule meets the 92-day threshold, the ARS credit formula applies as part of the guidelines calculation. It is not something a parent needs to separately argue for — it flows from the established parenting schedule. If the actual days with the child differ from what is ordered, however, courts may require evidence of the actual schedule when setting or modifying support.

What is Tennessee's child support enforcement process? The Tennessee Department of Human Services Child Support Services administers and enforces support orders statewide. Enforcement tools available under Tennessee law include income withholding orders (wage garnishment), license suspension, tax refund interception, bank account levies, and contempt of court proceedings. Payments in most cases are processed through the state disbursement unit rather than exchanged directly between parents. For a broader look at the general child support framework, see our guide on how child support is calculated.