Does 40% Parenting Time Automatically Reduce Child Support in Alberta?

Under the Federal Child Support Guidelines (FCSG), the calculation of child support depends heavily on parenting arrangements. Where one parent has the children for more than 60% of the time, that parent is considered the primary caregiver. In those cases, the other parent typically pays section 3 child support, which is the Guideline table amount based on their Guideline Income.

When each parent has the children at least 40% of the time, the arrangement is called shared parenting. Section 9 of the FCSG then applies. Many assume that this means support automatically shifts to a simple “set-off”: you calculate what each parent would pay under the tables, subtract the smaller from the larger, and the higher earner pays the difference.

While that is a common approach, the Supreme Court of Canada in Contino v. Leonelli-Contino made it clear: the set-off is not automatic.

What Contino Says

The Court emphasized that crossing the 40% threshold does not necessarily create an entitlement to a reduction in child support. Instead, section 9 requires a holistic and child-focused inquiry into three factors:

1. The set-off of the table amounts.
2. The increased costs of shared custody, such as the need to maintain duplicate housing, clothing, and transportation arrangements. The Court noted that these “fixed costs” do not diminish simply because one parent takes on slightly more parenting time.
3. The means, needs and circumstances of both parents, and the child. A central concern is whether the child would experience a significant disparity in the standard of living between households.

The table amounts from the Guidelines are not based on each family’s precise budgets. Judges therefore must use discretion to balance fairness with the child’s best interests. In practice, courts often require evidence such as budgets and records of actual spending in order to assess the “increased costs of shared custody” under section 9. The Supreme Court in Contino highlighted the value of this kind of evidence, noting that child budgets should include both direct costs (like food and clothing) and a share of household costs (such as accommodation and transportation).

Where no reliable evidence is provided, courts may presume that the recipient parent’s fixed costs remain unchanged and their variable costs are reduced only modestly by the other parent’s increased access. In such cases, the default may be to maintain support at the full table amount.

Example: Father Moves to 40% Parenting Time, No Change to Support

For several years, a mother has the children 61% of the time, and the father has them 39%. Under section 3, the father pays full table support. Later, the father gains a few additional days and now has the children 40% of the time.

Some parents might assume this automatically triggers a set-off calculation and a sharp reduction in support payable from the father to the mother. But as Contino makes clear, that is not the law. The mother may still bear high fixed costs of maintaining the children’s primary residence: housing, utilities, and clothing. These costs do not shrink in proportion to a small shift in parenting time. Ordering a strict set-off could dramatically reduce support even though the children’s needs and the mother’s expenses remain largely unchanged.

The Court in Contino cautions against such a “cliff effect.” Instead, judges must weigh the evidence and decide whether, in light of all the circumstances, a change in support is justified, and if so, to what extent.

Example: Set-Off Applied, Support Reduced

Contrast that with a case where the parents have closer to equal incomes and the father, now at 40% parenting time, produces a documented budget showing he covers the children’s clothing, activities, and an extra bedroom in his home. The mother’s fixed costs are real but not dramatically higher than his. Here, a court is far more likely to apply something close to the straight set-off, because the evidence shows both households are genuinely sharing the financial load, not just the calendar. The outcome in any given case depends on what the evidence actually shows, not on which side of the 40% line the parents land on.

If You’re Seeking More Parenting Time

More time with your children is not, by itself, a support strategy. If a support reduction matters to you, the parenting time increase has to come with real evidence: a budget showing what you actually spend on the children, receipts, and records that show you are covering costs beyond just having them under your roof more often. Courts want proof of increased financial responsibility, not just increased hours.

If You’re Worried That More Parenting Time Will Reduce Support

Crossing 40% does not automatically cut what you receive. Courts recognize that your fixed costs, housing, utilities, and the basics of keeping a home running for your children, do not disappear because the other parent has a few more overnights. If the other parent cannot show real increased spending on the children, a court can and often will keep support at or near the full table amount.

The Takeaway

Crossing the 40% threshold does not guarantee a reduction in child support. It simply opens the door to a case-by-case analysis guided by Contino. Courts will consider the real costs of shared parenting, the financial situations of both parents, and above all, the child’s welfare.

If you are seeking a change in support based on a change in parenting, it is important to put forward the evidence required by Contino to allow the court to assess the increased costs of shared parenting as well as the standards of living in each household.

Frequently Asked Questions

Does 50/50 custody mean no child support in Alberta?

No. Even at exactly equal parenting time, the higher-earning parent typically still pays support, and the amount depends on the section 9 factors, not just the schedule.

What happens if I get more parenting time?

Reaching 40% opens the door to a possible support adjustment, but it is not automatic. You need evidence of your actual increased costs and spending on the children.

Can I still get child support with shared parenting?

Yes. While the “set-off” amount is the typical arrangement, Courts can maintain support at or near the full table amount in shared parenting arrangements where the recipient parent’s fixed costs remain high, and there is little evidence the paying parent has taken on comparable costs.