Guaranteed Income Supplement (GIS) and Allowance for the Survivor are both income-tested benefits that are part of the Old Age Security (OAS) program. They are designed to provide financial assistance to low-income seniors who meet certain eligibility criteria. GIS is a monthly payment that supplements the OAS pension for seniors whose income is below a certain threshold. Allowance for the Survivor is a monthly payment for low-income seniors aged 60 to 64 whose spouse or common-law partner has died and who have not remarried or entered into another common-law relationship. The benefit amounts for both GIS and Allowance for the Survivor depend on the income level of the recipient and are adjusted quarterly based on the Consumer Price Index. The higher the income, the lower the benefit amount, until it reaches zero at a certain income limit. Therefore, eligibility for both GIS and Allowance for the Survivor depends on income level.

Canadian Investment Funds Course, Chapter 5: Registered Plans1