Official websites use
.gov
A .gov website belongs to an official government organization in the United States.
Secure
.gov
websites use HTTPS
A
lock
(
)
or
https://
means you’ve safely connected to the
.gov
website. Share sensitive information only on official, secure websites.
A value set expansion is the actual list of codes, calculated using a specified expansion profile of code system versions and any predetermined retired (legacy) codes used with implementation of the value set.