Maria T. Codina Leik, MSN, ARNP, FNP-C, AGPCNP-BC, is the president and principal lecturer at National ARNP Services, Inc. (npreview.com). Well known for her ability to simplify complex concepts, she is a popular speaker and educator. Ms. Leik previously taught in the nurse practitioner program at Florida International University Graduate School of Nursing. She is board certified by the American Academy of Nurse Practitioners Certification Board (AANPCB) and American Nurses Credentialing Center (ANCC) in two specialties: Family Nurse Practitioner and Adult-Gerontology Primary Care Nurse Practitioner. She is an experienced nurse practitioner with more than two decades of clinical practice. Ms. Leik is the author of Family Nurse Practitioner Certification Intensive Review and Adult-Gerontology Nurse Practitioner Certification Intensive Review, which are both in their fourth editions, and a member of Sigma Theta Tau International Honor Society of Nursing.