Maryland State Regulations, COMAR 13A.10.01 require that a student's home instruction instructional program be supervised.  Parents select one of two options for supervision:

Option A - The program is supervised by the Home Instruction Office, AACPS   Option A Details

ABCs of AACPS Home Instruction Supervision

AACPS Home Instruction Supervision - Portfolio Review Requirement by Date of Enrollment

Option B - The program is supervised by an approved private organization.  These supervisory organizations are known as "Nonpublic Entities" and must be registered with and approved by the Maryland State Department of Education.