Am working in office for neurologist who does consultations in hospital. Was told only ICD-10 codes related to neurology should be listed on claim when billing CPT E/M Consult/Followup and Procedures codes for services provided to patients while in hospital by our doctor.

Question 1: Was informed we should first list the "admitting diagnosis" (not the "principal diagnosis") found on the hospital’s billing summary along with only the neurology codes listed. Does this sound right?

Question 2: Should we be listing ICD-10 codes for co-morbidities and/or complications that affect the neurologist’s treatment/medical management of patient? For example, patient has stroke and also has AFib. Shouldn’t we list the ICD-10 codes for both stroke and AFib?

Question 3: When a consult or followup are done on the same date of service as an EEG and/or lumbar puncture (spinal tap) as an inpatient, what modifiers should be attached to E/M and/or procedure codes for the neurology specialist performing them? Debating use of modifier 59 vs. XE when FUp, EEG, and lumbar puncture are done at different times on same date of service. Also, do we have to use HCPCS code AF on E/M or procedure codes to indicate specialist physician service as well as -59 or -XE modifier?

Any helpful advice/guidelines would be appreciated. Thank you.