The answer really depends on the payer. Are the providers in the same specialty or different specialties/subspecialties? Providers within the same group and with the same tax ID number may have different specialties/subspecialties; therefore, it doesn't necessarily matter if the tax ID is the same if a provider in the same group is a different subspecialty and thus is reporting a new patient code. If they are the same specialty and same group tax ID, you likely cannot bill the patient as a new patient within three years, but check with the payer.
You can submit the claim as a new patient encounter if the providers are of different subspecialties, but your payer may deny the claim based on the same tax ID (which may be what is happening in your case). If that is the case, consider appealing the denial.
Remember, too, that what your practice calls a subspecialty may not be recognized by the payer as a subspecialty. So be sure to check with your payer; and appeal any new patient claims that you feel warrant new patient codes, instead of established patient codes, due to subspecialty differentiation between providers.
Hope that helps!
Leesa A. Israel, BA, CPC, CUC, CEMC, CPPM, CMBS, AAPC MACRA Proficient
Head of Publishing, Editorial & Technology
AAPC