• Allegany
• Anne Arundel
• Baltimore
• Calvert
• Caroline
• Carroll
• Cecil
• Charles
• Dorchester
• Frederick
• Garrett
• Harford
• Howard
• Kent
• Montgomery
• Prince George’s
• Queen Anne’s
• St. Mary’s
• Somerset
• Talbot
• Washington
• Wicomico
• Worcester

Additionally, Baltimore City is treated as a county-level entity but is separate from Baltimore County.