§ 6.7 Movement of persons between the civil service system and other merit systems.
Primary source
Verbatim text below is from the Electronic Code of Federal Regulations (eCFR), a public-domain U.S. government work. Always verify the current version with the eCFR before relying on it for any legal matter.
Full Text
Whenever OPM and any Federal agency having an established merit system determine it to be in the interest of good administration and consistent with the intent of the civil service laws and any other applicable laws, they may enter into an agreement prescribing conditions under which persons may be moved from one system to the other and defining the status and tenure that the persons affected shall acquire upon such movement.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.