Children’s Medical Services, also called CMS, is a program of the Maryland Department of Health and Mental Hygiene (DHMH). CMS can help low-income, uninsured or underinsured Marylanders ages 0-21 years get specialty care for a chronic illness or disability by paying for needed services. Harford County Health Department staff can assist with completing applications.  Please call 410-273-5626 for further information..