People who have lived in Canada for 40 years after turning 18 may receive full Old Age Security, according to the Service Canada government website. People born before July 1, 1952, may also be eligible if they meet residency requirements. An extra Guaranteed Income Supplement is available to low-income OAS recipients.
Those born before July 1, 1952, are eligible for OAS if they resided in Canada on July 1, 1977, or if they resided in Canada before July 1, 1977 and after turning 18, explains the Government of Canada. People who possessed a valid Canadian immigration visa on July 1, 1977, may also be eligible for full OAS if they have lived in Canada for the 10 years prior to applying. Eligibility also extends to those who have lived in Canada three years for every one year not lived in Canada during the 10 years prior to applying. People not born before July 1, 1952, and who have not lived in Canada for 40 years, may be eligible for partial OAS payments calculated at 1/40 for every year lived in Canada.
The Canadian government states that some low-income Canadians may also be eligible for the Guaranteed Income Supplement on top of full OAS payments. An applicants' income determines GIS payments. Service Canada provides a chart of GIS payments. To find this chart, click the Seniors link under the Services tab, then click Guaranteed Income Supplement, and find the Maximum Annual Income link in the text.