When the whole NPI thing came about, I was (unfortunately) put into a special project group at the facility I worked for and all day we'd enter the applications for all the providers in our group, so that's where most of my knowledge comes from. Given that it's a very large teaching facility, you can only imagine how many providers we had to process through the NPI application,
individually. Glad that's over, never wanna do that again.
Regarding specialty vs subspecialty... using Internal Medicine as an example, IM would be the specialty. Now, there's a massive number of types of IM providers (as you know). That's where subspecialty comes in; Geriatrics, Hematology, Oncology could all fall into the umbrella of IM. The key component to the whole specialty/subspecialty thing is based totally on what the providers have listed as their specialty and subspecialty within their individual NPIs. So when Medicare looks at a provider, they first see a Tax ID (which defines the group they are part of), then looks at that provider's NPI information to see what specialty and subspecialty (if applicable) they have. Because the application for an NPI includes that provider's taxonomy code(s), in a round-about way, they are looking at the taxonomy codes as well. They still have to pick the "primary" specialty/subspecialty if they submit more than one taxonomy code. This kind of explains it better:
https://www.cms.gov/medicare/provid...ation/medicareprovidersupenroll/taxonomy.html
If all the providers there are Internal Med, try drilling down to their subspecialty. I assume each of them has a particular area within IM that they specialize in...? If so, then that should be included in their NPI information as their subspecialty. In such a case, all of the providers may have an IM specialty, but if their subspecialties differ, then that's a whole different ballgame. Again, it all goes back to the NPI information for each individual provider. Generically speaking in a theoretical situation, let's say Dr. A primarily sees patients with breast cancer and Dr. B primarily sees patients with lung cancer. While treating a patient with breast cancer, Dr. A sees something that might indicate the cancer had metastasized to the lungs, so Dr. A sends the patient to Dr. B to evaluate it. They are both in the same group, they both have a specialty of IM, but if they have specialties related to the cancer type (breast vs lung), then one could make the argument that the patient would be new to Dr. B due to the different subspecialty. I don't know if such a set-up exists, but it's food for thought.
I can't answer your question about the admit and consult because there's NO consult codes for Medicare, as you mentioned
I could probably work through that example if it was an admit other than hospice. Medicare and Hospice and I don't get along with each other very well.