Final answer:
Certified nursing facilities require a full-time social worker when they have more than 120 beds.
Step-by-step explanation:
A full-time social worker is required in certified nursing facilities with more than 120 beds. The recommendation from the International Association of Counseling Services regarding staffing is not directly related to the requirements for social workers in nursing facilities. Instead, they suggest one full-time equivalent staff member for every 1,000 to 1,500 students for counseling services, which is a different context. For nursing facilities, the Centers for Medicare & Medicaid Services (CMS) generally govern the requirements for such staffing, and they stipulate that a full-time social worker must be employed for facilities with more than 120 beds.