GIS and OAS: Retroactive Lump-Sum Payments

A May 7, 2026 Federal Court of Appeal case examined a taxpayer who received a $69,144 lump-sum payment relating to salary and interest from a wrongful dismissal dispute covering earlier years.

For income tax purposes, the salary portion qualified as a retroactive lump-sum payment and could effectively be taxed as though it had been received in the earlier years to which it related.

However, the treatment was different when determining eligibility for the Guaranteed Income Supplement (GIS).

Taxpayer Loses

The entire lump-sum payment was included in the taxpayer's income for GIS purposes in the year received.

This pushed the taxpayer's income above the threshold and resulted in the loss of GIS for the twelve-month period beginning the following July.

The court confirmed that although income for GIS purposes is calculated similarly to taxable income, the two calculations are not identical.

The newsletter notes that the same general concept can also apply to Old Age Security (OAS).

Action: Before receiving a significant one-time payment, consider whether it could reduce or eliminate income-tested benefits such as GIS or OAS.