Social Security Benefits Guarantee Act of 1999

Social Security Benefits Guarantee Act of 1999 - Directs Secretary of the Treasury to issue to each individual receiving benefits under title II (Old Age, Survivors and Disability Insurance) (OASDI) of the Social Security Act, and to each individual who applies for such benefits, a certificate representing a legally enforceable guarantee (entitlement): (1) of the monthly amount of OASDI benefits the individual will receive, determined as of the certificate's date of issuance; and (2) that the benefits will be adjusted not less frequently than annually on the basis of an accurate determination of the increase in the individual's cost-of-living.