I would suggest the best word for doing this act is Retire or Retiring. Retire is defined as:
- To withdraw; to retreat; to go from company or from a public place into privacy; as, to retire from the world; to retire from notice. [emphasis my own]
Example: "Record Number of Teachers Set to Retire"(1)
The word you're looking for is Retirement:
- The act of withdrawing from company or from public notice or station.
In the modern day, we speak of things such as Retirement Plans(2) or Retirement Rates(3)
We refer to a person so withdrawn as simply Retired. This may sometimes be made into a proper title, The Retired (4), to refer to significant socioeconomic groups of such people, sometimes requiring further specification of which group is retired. Other connotations for the word exist, such as voluntary withdrawal from society or the dissolution of business but the connotation of quitting one's job or position is the primary use.
N.P.R. (National Public Radio)
Types of Retirement Plans, I.R.S. (Internal Revenue Service)
Why Are Retirement Rates So High at Age 65? Robin L. Lumsdaine, James H. Stock, and David A. Wise (scholar.harvard.edu)
I.C.A.S (Institution of Chartered Accountants of Scotland) Membership for The Retired
All referenced dictionary definitions come from Noah Webster's American Dictionary of the English Language, (1828).