Receiving a tax slip for the Guaranteed Income Supplement (GIS) can make it look as though the benefit is taxable. Your T4A(OAS) shows the amount, and you have to enter it on your income tax return. However, reporting GIS and paying income tax on GIS are two different things. GIS is generally not taxable in Canada. The amount appears in box 21 of your T4A(OAS) and is reported on line 14600 of your federal tax return. An offsetting deduction is generally claimed on line 25000, which prevents GIS from being included in taxable income.
Why Do You Report GIS If It Is Not Taxable?
The unusual part of GIS taxation is that the benefit still passes through your tax return. The net federal supplements reported on line 14600 include GIS as well as the Allowance and Allowance for the Survivor. Your GIS amount appears in box 21 of the T4A(OAS). You transfer that figure to line 14600 when completing your return. The T4A(OAS) instructions then direct taxpayers to the corresponding deduction rules.
For most GIS recipients, the amount flows back out through line 25000, Other payments deduction. So seeing GIS included in the income section of your return does not mean the same amount becomes taxable income.
GIS and OAS Have Different Tax Treatment
The tax treatment changes when you separate GIS from the Old Age Security pension itself. Regular OAS pension payments are taxable and are reported from box 18 of the T4A(OAS) on line 11300. GIS is handled through the separate reporting and deduction process described above.
That difference matters because the two benefits can arrive together. A single deposit into your bank account does not mean every dollar in it receives identical tax treatment. Our explanation of OAS versus GIS covers the broader differences between the programs, while the OAS tax rules deal specifically with the pension portion.
Does GIS Increase Your Taxable Income?
For a typical GIS recipient who can claim the corresponding deduction, GIS does not remain in taxable income after the deduction is applied. The line 25000 deduction removes the applicable net federal supplement amount from the income used to calculate federal tax.
There is an important technical exception. For the 2025 tax year, special calculations can apply when net income before adjustments exceeds $93,454, particularly where a social benefits repayment is involved. That situation is far outside the income range in which someone would ordinarily receive GIS, but it explains why the tax-return instructions use language such as “may be able to deduct” rather than treating line 25000 as an unconditional rule in every possible return.
For someone receiving GIS under ordinary circumstances, we would focus on whether box 21 has been entered correctly rather than treating the amount on line 14600 as a new taxable pension.
Where to Find GIS on Your T4A(OAS)
Your T4A(OAS) separates the main OAS pension from federal supplements. Box 18 contains the taxable OAS pension paid, while box 21 contains the net amount of GIS, Allowance or Allowance for the Survivor received during the year.
That separation makes the slip easier to check before filing. Do not combine boxes 18 and 21 and report the total as OAS pension income. Each amount has its own place on the federal return.
The slip is issued annually, and it can also be viewed electronically once available through your government accounts. Anyone learning how the benefit itself works can start with our Guaranteed Income Supplement explanation.
Does GIS Affect Other Income-Tested Benefits?
A benefit can be non-taxable and still appear in calculations elsewhere on a tax return. That is why “not taxable” should not automatically be read as “irrelevant to every income-based calculation.”
For federal tax purposes, net federal supplements are included when calculating certain intermediate income figures before the line 25000 deduction. The precise effect depends on the calculation involved. We would therefore avoid assuming that GIS has no effect on another credit, benefit or repayment simply because no regular income tax is payable on the GIS itself.
The reverse issue is often more important for GIS recipients: other income can reduce the amount of GIS you receive. CPP payments, pension income, RRSP or RRIF withdrawals and several other income sources can enter the benefit calculation. Our breakdown of how GIS is calculated and what income counts deals with that separately.
Other Questions About GIS and Taxes
Do you get a tax slip for GIS?
You receive a T4A(OAS) covering applicable OAS amounts and federal supplements. GIS is shown in box 21 rather than the box used for the regular OAS pension.
Can income tax be deducted from GIS payments?
GIS is not treated like ordinary taxable pension income. If your combined OAS payment includes taxable OAS pension income, however, tax deductions associated with your OAS can make the overall deposit and tax slip more complicated than looking at GIS alone.
Does a retroactive GIS payment become taxable because it is paid as a lump sum?
Its tax character does not change merely because several months of GIS arrive together. A delayed payment can still create separate reporting questions, which we cover in our explanation of GIS retroactive payments.
What should you do if the GIS amount on your T4A(OAS) looks wrong?
Compare box 21 with your payment records before filing. If the slip does not match the GIS you received or an adjustment made to your account, contact Service Canada about the benefit amount rather than changing the slip figure on your own.
