No, SS retirement is not now and has not been paid out of treasury operating funds since 1940 when the SS trust funds were created. Payroll taxes flow into the trust fund accounts when received by the treasury. Interest on treasury bills are credited to these trust fund accounts. The actual checks are deposited in the New York Federal Reserve Bank. Beneficiaries are paid out of these account. Treasury bills are bought with excess funds in these accounts monthly and Treasury bills are sold back to the treasury when needed to pay benefits or when they mature and are credited to the trust fund accounts.
What is being payed out of operating funds is SSI, Supplemental Social Security Income which provides a benefit for those so badly disabled that they can not work. Although this program carries the name Social Security and is administered by social security it has been funned out of the general fund since 1974. Unlike the Social Security retirement system and Disability Insurance, SSI is a welfare program. It replaced the federal-state adult assistance programs.
The Social Security funds are trust funds which are legal entities governed by the trust documents from the1940 legislation, not to be confused with various goverment accounting funds such as the Operating Fund, Emergency Fund, etc. These trust funds are administered by a board of trustees, 4 are cabinet secretaries and 2 appointed by the president and approved by congress.
The 6.6% S.S. payroll taxes and matching funds from employers plus treasury bond interest is the sole source of funding of both of the Social Security Retirement Fund and the Disability Insurance Fund. SS is required by law to invests account balances in treasury bills monthly and redeem them when money is needed to pay benefits or when they mature.