Old Age Security (OAS) is indexed to inflation, but its adjustment schedule is easy to misunderstand. Unlike some benefits that change once a year, OAS can change several times during the year. In 2026, OAS payments are reviewed four times a year and can increase when the cost of living rises, as measured by the Consumer Price Index (CPI). Adjustments take effect in January, April, July and October. If the relevant CPI calculation falls instead, the OAS pension rate does not decrease.
OAS Is Adjusted Four Times a Year
The 2026 OAS indexing system divides the year into four payment quarters. A revised rate can therefore take effect on January 1, April 1, July 1 or October 1.
An adjustment is not guaranteed every quarter. The Old Age Security Act requires quarterly adjustments when the applicable Consumer Price Index calculation supports an increase. Consequently, periods of relatively stable prices can produce little or no change.
That quarterly schedule is useful for another reason. A rise in inflation does not have to wait until the following calendar year to affect OAS rates. However, the adjustment also does not immediately mirror the inflation figure reported for a single month because the calculation uses three-month CPI averages.
How the OAS Inflation Calculation Works
The CPI tracks changes over time in the prices Canadian consumers pay for a basket of goods and services. For OAS indexing, the 2026 calculation compares the average CPI across the most recent applicable three-month period with the relevant earlier three-month average.
The July to September 2026 adjustment shows how the calculation works. The average CPI for February, March and April 2026 was 167.1, compared with 165.1 for November and December 2025 and January 2026. Dividing the difference by the earlier average produced a 1.2% increase in OAS benefits for that quarter.
This three-month averaging matters because OAS does not simply take Canada’s latest headline inflation rate and add the same percentage to the next pension payment. Monthly CPI can move sharply in either direction, while the indexing formula uses the prescribed comparison periods.
OAS Does Not Go Down When the CPI Falls
The 2026 indexing rules include protection against a reduction in the basic pension rate. When the applicable CPI average is lower, the monthly OAS pension cannot be reduced because of that CPI decline.
Instead, no inflation adjustment is made for that payment quarter. The legislation also accounts for the lower CPI when determining when a later increase can occur. As a result, falling prices can delay a future increase rather than cutting the established OAS rate.
This rule is particularly useful when diagnosing a smaller deposit. A lower amount reaching your bank account can have other causes, which we cover separately in why an OAS payment can go down. A negative CPI reading itself is not one of them.
How Much Is OAS Increasing in 2026?
For July to September 2026, OAS benefits increased by 1.2% from the previous quarter. That put the year-over-year increase from July 2025 to July 2026 at 2.3%.
The next adjustment has already been determined. For October to December 2026, OAS benefits will rise by 1.4%. The increase from October 2025 to October 2026 will therefore be 3.0%.
The percentage increase applies through the indexing formula rather than giving every recipient the same dollar increase. Someone receiving a partial pension will consequently see a smaller dollar change than someone receiving the maximum pension. The separate maximum OAS payment page tracks the current dollar amounts rather than duplicating them here.
Other Questions About OAS Inflation Indexing
Does OAS use Canada’s national CPI or a provincial inflation rate?
OAS indexing uses the Consumer Price Index for Canada. Your province’s inflation rate does not separately determine your OAS adjustment.
Are partial OAS pensions indexed too?
Yes. A partial OAS pension remains based on the portion of the full pension to which you are entitled, while changes to the full pension rate flow through to the partial amount. The underlying fraction is determined by the OAS calculation rules.
Are the Guaranteed Income Supplement and OAS Allowances indexed for inflation?
Yes. The 2026 quarterly adjustment system also applies to OAS benefits such as the Guaranteed Income Supplement (GIS), the Allowance and the Allowance for the Survivor. Their maximum amounts are subject to the same quarterly CPI-based adjustment framework.
Do you have to apply to receive an OAS inflation increase?
No. Once you are receiving OAS, CPI-based adjustments are applied automatically. There is no separate application or request required for an indexed increase.
For the next change, check the current OAS payment amounts and quarterly adjustment after the new rate is published rather than estimating it from a monthly inflation headline.
