Good question. The rules are a great resource for definitions.
Here is the definition straight from the rules:
A “LCP” is an individual licensed to provide health care and health services, without direction or supervision and who qualifies for and has received a National Provider Identifier (NPI) from the Centers for Medicare and Medicaid Services. Examples of LCPs include physicians, psychologists, dentists, and, when delivery of health care or services without supervision is authorized by the individual’s license, nurse practitioners, physician’s assistants, certified nurse-midwives and licensed independent social workers.