OAS Explained: Old Age Security in Canada

Old Age Security, or OAS, is a monthly pension for Canadians aged 65 and older. Unlike the Canada Pension Plan, it is not something you pay into directly; it is funded from general government revenue, and you qualify based on your age and years of residency in Canada rather than your work history. OAS is taxable, it is subject to a recovery tax once your income is high enough, and you can defer it to age 70 in exchange for a larger amount.

This guide explains how OAS eligibility works, how the clawback operates, and how OAS fits with CPP and the Guaranteed Income Supplement. It is written for pre-retirees and retirees in Ottawa and across Ontario who want to understand and, where possible, protect this benefit. Treat it as general education and confirm your own figures with Service Canada.

What OAS is and how you qualify

OAS is a residency-based benefit. You generally become eligible at 65 if you have lived in Canada for enough years, regardless of whether you worked or contributed to any plan. This is the key distinction from CPP, which is earned through contributions during your working life. The two are often confused, and our comparison in CPP versus OAS explained sets them side by side.

The residency requirements work as follows:

• Full OAS generally requires 40 years of residency in Canada after age 18.
• Partial OAS is available with at least 10 years of residency, paid at 1/40th of the full amount for each year lived in Canada.

For newcomers to Canada, international social security agreements can sometimes help bridge the minimum residency requirement, which matters for the many immigrants who settle here mid-career. This connects to broader planning for new immigrants to Canada.

Deferring OAS to 70

You do not have to take OAS at 65. You can defer it for up to five years, and for each month you wait the benefit increases by about 0.6%, reaching roughly 36% more if you start at 70. Unlike CPP, OAS cannot be started before 65.

Deferral can be attractive for a few reasons. If you have other income to live on in your late 60s, a larger inflation-indexed benefit later provides stronger protection against outliving your money. Deferral can also reduce clawback exposure during years when your income is temporarily high, for example while you are still winding down work. The decision depends on your health, your other income, and your tax picture, so it rewards modelling rather than a default choice.

The OAS clawback

The feature that most affects higher-income retirees is the OAS recovery tax, universally known as the clawback. Once your net income passes an annual threshold, you must repay 15 cents of OAS for every dollar of income above that level. At a high enough income, the entire OAS pension is recovered.

Because the clawback is driven by reported income, it can often be managed. Strategies include:

• Smoothing taxable income across years rather than letting it spike.
• Drawing on TFSA savings, whose withdrawals do not count as income, in higher-income years.
• Timing RRSP and RRIF withdrawals thoughtfully, since they are fully taxable.
• Using pension income splitting with a spouse to keep both incomes below the threshold.
• Realising capital gains deliberately rather than all at once.

We explore these in detail in OAS clawback explained. The central point is that the clawback is not simply bad luck; for many retirees it is partly within their control.

OAS, CPP, and GIS together

OAS is the foundation of Canada’s public retirement income system and a prerequisite for the Guaranteed Income Supplement. The three programs interact in ways worth understanding.

Program	Based on	Taxable	Income-tested
OAS	Residency	Yes	Yes, via the clawback at higher incomes
CPP	Contributions	Yes	No
GIS	Residency and low income	No	Yes, reduced as income rises

A lower-income senior may receive OAS plus GIS, with GIS falling as other income rises. A higher-income senior may receive OAS but lose some or all of it to the clawback. CPP sits between, unaffected by income testing but counting as income for both GIS and the OAS clawback. For the low-income side of this picture, see GIS explained.

Applying for OAS and automatic enrolment

Many Canadians are enrolled in OAS automatically and simply receive a letter from Service Canada before they turn 65. Not everyone is, however, and if you are not automatically enrolled you must apply. It is worth confirming your status well before 65 so that payments are not delayed, and so that you can make a deliberate choice about whether to start at 65 or defer.

If you decide to defer, you do so by not starting the pension and informing Service Canada as appropriate. Because the deferral increases the benefit for each month you wait, the decision should be made consciously rather than by missing a deadline. People who are still working at 65, or who have other income to draw on, are often the best candidates to consider deferral.

OAS for time spent outside Canada

OAS is unusual among retirement benefits in that it can continue to be paid even if you leave Canada, provided you have enough years of residency. In general, if you have at least 20 years of residency after age 18, OAS can be paid abroad indefinitely; with fewer years, payment outside Canada may be limited to a period after you leave. This matters for retirees who split their time between Canada and elsewhere, and for those considering spending part of retirement abroad. The residency requirements and the interaction with international agreements have detail, so anyone planning time outside the country should confirm how their OAS, and any GIS, would be affected before relying on it.

How OAS fits your plan

For most retirees, OAS is a modest but reliable, inflation-indexed layer of income. Its planning value lies less in the amount and more in the decisions around it: when to start, how to avoid the clawback, and how to coordinate it with CPP and your own withdrawals. These choices affect your after-tax income and how long your savings last.

The clawback in particular rewards planning done before and during the years it would otherwise apply. A retiree who manages the timing and source of income can often keep more of their OAS than one who draws from accounts in the default order.

There is also a higher age supplement built into OAS: the pension increases at a set age later in retirement, recognising that very old age often brings higher costs and lower other income. This is automatic and needs no application, but it is worth knowing it exists when projecting income across a long retirement.

A note on timing OAS with the rest of your plan

The OAS start date should not be chosen in isolation. For many retirees, the years immediately after stopping work but before public benefits begin are the best window to draw down RRSP savings at a lower tax rate, before CPP and OAS add to taxable income. Starting OAS later can extend that window and, by increasing the eventual benefit, provide stronger inflation-indexed income in advanced age. For others, particularly those who need the income or expect a shorter life, starting at 65 is the sensible choice. The decision interacts with your RRSP-to-RRIF schedule, your CPP timing, and your tax bracket in each year, which is why it belongs inside a full retirement income plan rather than being settled on its own.

Next step

OAS looks simple, but the deferral decision and the clawback make it one of the more plannable parts of a retirement income strategy. Small adjustments to how and when you draw income can protect a benefit that lasts for life.

Our retirement planning and tax planning work helps Ottawa and Ontario retirees start OAS at the right time and structure income to minimise the clawback. If you are approaching 65 or already receiving OAS, book a private consultation and we will review your options.