8/15 1994 – The U.S. Social Security Administration became an independent government agency. It had been a part of the Department of Health and Human Services agency. 

At a historic White House bill-signing ceremony on August
15 1994, Public Law 103-296-Social Security Independence
and Program Improvements Act of 1994-was signed into law.
President Bill Clinton symbolically used one of the pens President Franklin Roosevelt had used when he signed the original
Social Security Act 59 years ago, on August 14,1935. The new
legislation officially separates the Social Security Administration
(SSA) horn the Department of Health and Human Services
(HBS), effective March 3 1, 1995, and restores the SSA to its
original status as an independent Federal agency. (Since 1939,
SSA has operated under the direction of a “parent” agency.)
A single administrator will lead the agency with a seven-member
bipartisan advisory board. Also contained in the new law is a
number of other major changes affecting the Social Security and
supplemental security Income (SSI) programs.

for more go to ssa.gov    … a pdf file