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Why Is My OAS Less Than the Maximum? Partial OAS Explained

Updated

This page explains why an OAS payment can be below the published maximum. The most common reason is a partial pension based on years of residence; the clawback and non-resident tax are the others. The OAS guide covers OAS in general.

Partial OAS by years of residence (October to December 2026)

A full OAS pension needs 40 years of residence in Canada after age 18. With fewer years, OAS pays 1/40 of the full pension for each year, as long as you have at least 10 years while living in Canada (or 20 years to be paid while living abroad).

Partial OAS = years of residence after age 18 ÷ 40 × the full pension

Years in Canada after 18Share of full pensionMonthly OAS (age 65 to 74)Annual OAS
10 (minimum)0.250$190.63$2,288
120.300$228.75$2,745
150.375$285.94$3,431
200.500$381.25$4,575
250.625$476.56$5,719
300.750$571.88$6,863
350.875$667.19$8,006
40 or more1.000$762.50$9,150

The share is set when your pension is approved and doesn’t change afterward, but the dollar amount rises with the quarterly indexation, and by 10% at age 75. (Source: Service Canada, OAS benefit amount.) The maximum OAS payment page lists the current full amounts.

What counts as residence

Residence means living in Canada and making it your home; the full rules are in am I eligible for OAS. Years before age 18 don’t count, and neither do years you lived abroad, with one exception: time working outside Canada for a Canadian employer can count as residence in Canada, under the conditions in what counts as residence.

Social security agreements

Canada has social security agreements with nearly 60 countries. If you lived or worked in one of them, the periods there can be added to your Canadian residence to meet the 10-year minimum (or the 20-year minimum for being paid abroad), and you may receive both a partial OAS and a pension from the other country. The agreement helps you qualify; the OAS amount is still based on your years in Canada.

Other reasons for a lower payment

  • The clawback. If your net income was above $93,454 (2025 income), part of your OAS is withheld from July 2026 to June 2027 as recovery tax. See the OAS clawback.
  • Tax withheld. If you asked Service Canada to withhold income tax, or you live outside Canada and non-resident tax applies, the deposit is lower than the pension. See is OAS taxable?.
  • Starting later. Deferring doesn’t lower the payment; it raises it by 0.6% per month of delay. See deferring OAS.

If your income is low: the GIS

If a partial OAS leaves your income low, you may qualify for the Guaranteed Income Supplement, a monthly payment for OAS recipients who live in Canada. OAS itself isn’t counted as income for the GIS, and most other income reduces the GIS by 50 cents per dollar. The GIS maximum for a single person is $1,138.90 a month (October to December 2026). With a partial pension, the maximum GIS is increased by the amount your OAS falls short of the full pension, so at low incomes the GIS makes up most or all of the gap. (Old Age Security Act, s. 12(5).) The exception is someone who qualified only through a social security agreement with fewer than 10 years in Canada: their GIS is prorated by years in Canada ÷ 10 (ESDC, OAS program toolkit).

What you can do

SituationOption
You think your years of residence were counted wrongAsk Service Canada for a reconsideration and send proof of residence
You lived or worked in an agreement countryApply under the social security agreement
You haven’t started OAS yetEach more year of residence before you start adds 1/40; delaying adds 0.6% per month
Your income is lowApply for the GIS
You applied lateService Canada can pay up to 11 months retroactively (how and when to apply)

The OAS calculator estimates your payment from your years of residence and start age.

Sources

The figures and rules on this page come from these sources, last checked against them on September 29, 2026. How we check facts.