This paper presents some observations on the financing of the United States (US) Social Security System from three different perspectives. The first part examines the relationship between the actuarial values of two projected streams of cash flows that represent the asset/income and liability/outgo for the system. This relationship is quantified by presenting the results of a cash flow adequacy test to measure the ability of the system to meet projected scheduled benefits over periods of 25, 50 and 75 years based on the official results from the latest Trustees Report. The second part explains the nature, operation, purpose and size of the Social Security Trust Funds, describes the securities held, and their maturity schedule and interest income features. The third part explores the dilemma arising from the fact that the assets held in the Trust Funds arising from the accumulated surplus of income over outgo are lent to the US Treasury; the Trust Fund holds special issue treasury bonds in respect of these loans and the amounts lent to the treasury are available for financing part of the Federal budget deficits. Although these securities are a legal obligation of the US Treasury, this use of the surplus funds creates a controversial “lent or spent” dilemma since the funds cannot be used for both the purpose of paying future Social Security benefits and for the purpose of financing current budget deficits.