The reimbursement classes for the Administrative and Routine cost center are as follows: Facilities in the Baltimore metropolitan region consisting of the following counties: Anne Arundel; Baltimore; Carroll; Harford; and Howard; Facilities in Baltimore City; Facilities in the Washington region consisting of the following counties: Charles; Montgomery; and Prince George's; Facilities in the nonmetropolitan region consisting of the following counties: Allegany; Calvert; Caroline; Cecil; Dorchester; Frederick; Garrett; Kent; Queen Anne's; St. Mary's; Somerset; Talbot; Washington; Wicomico; and Worcester. The reimbursement classes for the Other Patient Care cost center are based on the county groupings as specified in §A of this regulation. For services provided prior to July 1, 2019, the reimbursement classes for the Nursing Service cost center are as follows: Facilities in the Baltimore region consisting of Baltimore City and Baltimore County; Facilities in the Central Maryland region consisting of the following counties: Anne Arundel; Carroll; and Howard; Facilities in the Washington region consisting of the following counties: Charles; Frederick; Montgomery; and Prince George's; Facilities in the nonmetropolitan region consisting of the following counties: Calvert; Caroline; Cecil; Dorchester; Harford; Kent; Queen Anne's; St. Mary's; Somerset; Talbot; Wicomico; and Worcester; Facilities in the Western Maryland region consisting of the following counties: Allegany; Garrett; and Washington. Effective July 1, 2020, the reimbursement classes for the Nursing Service cost center are as follows: Facilities in the Baltimore Metro region consisting of Baltimore City and the following counties: Anne Arundel; Baltimore; Carroll; Cecil; Harford; and Howard; Facilities in the Washington Metro region consisting of the following counties: Calvert; Charles; Frederick; Montgomery; Prince George’s; and St. Mary’s; Facilities in the Eastern region consisting of the following counties: Caroline; Dorchester; Kent; Queen Anne’s; Somerset; Talbot; Wicomico; and Worcester; and Facilities in the Western region consisting of the following counties: Allegany; Garrett; and Washington. During the period July 1, 2019 through June 30, 2020, reimbursement for the Nursing Service cost center shall be the sum of 50 percent of the amount calculated in accordance with the reimbursement classes under §C of this regulation and 50 percent of the amount calculated in accordance with the reimbursement classes under §D of this regulation.