I am an LMHC, and I think education level and experience first, and then perhaps specialty. But I know I do not make enough after 11 years of practice I haven't paid a cent of $110K student loans with income based repayment plan. Librarians make triple what I make.

Years of experience, Day vs Night shift, specialty, census volume, running code blues, and city/state area cost of living

Experience

Experience, location, specialty and staff to patient ratio

I believe pay rate should be based on experience but also the type of patients and number of patients you are seeing. If the patients have many comorbidities and complex problems, then it will take more time, more charting, more order, follow-up, etc. to do your job. When you are working with patients of lower acuity, the issues are not as complex, then the pay rate may be lower. Another factor is the number of patients you are required to see in one day. If I see about 20 urgent care patients, it just not require as much focus and time as if I would see about 10 which are internal medicine or geriatric patients. Specialty also may be a consideration, such as ER or cardiology, for example. You may have a higher salary working for a specialty, but again the factors of acuity, complexity and patients per hour is an important factor.

I believe education and years of experience should be the main factor to determine pay rate.

Experience and speciality

Experience and location. Sometimes if MD has another useful attribute, such as multilingual.

Dependability, work ethic, longevity and ability to be available.

Experience, education, specialty