So looking at this from a technical point. NIH.gov has three name servers. Each host are still up, but only answering dns on TCP and not UDP. All three are located under the same AS, which implies that there is a single operator responsible. No ipv6. From the outside I can't see any sign that they have delegated operation of either the servers or the service to any external company.
Doing some more looking around, it seems like NIH has a department/group/structure called Center for Information Technology, which is the IT support side of NIH and are the operators for the DNS servers.
Doing some more looking around, it seems like NIH has a department/group/structure called Center for Information Technology, which is the IT support side of NIH and are the operators for the DNS servers.