The Old Age Security pension (or OAS or OAS-GIS) is a taxable monthly social security payment available to most Canadians 65 years of age or older with individual income less than $114,815.As of April 2015, the basic amount is $563.74 per month.f an individual does not qualify for a full pension, he/she may qualify for a partial pension if he/she meets these conditions: 1  Age 65 or older, and. 2  Canadian citizen or Permanent resident (Canada) who is living in Canada, AND. 3  Lived in Canada for the last 10 years.