While NOAA Commissioned Officer Corps and USPHS Commissioned Corps are both uniformed and have ranks, they are fundamentally non-military. Are military members expected to deliver/return salutes when encountering members of these Commissioned Corps?

What about the USCG when they aren't assigned to the Navy? My default would be yes to the USCG since they are an Armed Force; but I probably wouldn't think about it on initially running into anyone from the other two.

When I was a cadet we supported evacuation and life support operations for many nursing home and hospitals patients from Louisiana after hurricane Ike hit. They setup a makeshift "hospital" in Reed arena for several months. I volunteered often during the weeks they were there. We were briefed by the Trigon bulls that we would absolutely address the USPHS officers by their ranks and render all customs and courtesies. This was difficult because many of them were just wearing scrubs without ranks or name tags. If I remember correctly, the head of the USPHS at the time was an Aggie, and if you volunteered over a certain amount of hours you received a USPHS unit award. I received the award, and suppose I am technically authorized to wear it on my Army uniform. I have been active duty for over 10 years and haven't run into a USPHS officer in uniform, but if I did I would salute them if they outranked me.

https://today.tamu.edu/2009/02/13/aggies-to-be-honored-for-hurricane-ike-aid/

Since USPHS, and NOAA, officers are all commissioned officers of the uniformed services they are treated just like an officer of that grade in one of the Armed Services according to USC. Including Space Force now there are 8 uniformed services, that all have equivalent ranks and pay, but as you probably know only 6 of the 8 are Armed. So there really is no difference. USPHS Officers can also be assigned to support the Armed Services, for example USPHS officers provide medical care for the USCG. So the chief medical officer of the USCG is actually a USPHS officer.