St. Mary's County, Maryland property-tax rates and deadlines
Tax bills, payment rules, and valuation-review windows are controlled by the local jurisdiction and the governing state framework. The reviewed record below separates published figures from items that still require confirmation with Maryland State Department of Assessments and Taxation — St. Mary's County Assessments; St. Mary's County Treasurer's Office.
Rate context
PublishedFY2027 county real-property rate for July 1, 2026–June 30, 2027: $0.8478 per $100 assessed value; municipal rates vary.
Statement mailing
Confirmofficial county source reviewed does not publish a specific 2026 mailing date; the tax-year guidance says to contact the Treasurer if the bill is not received by August 15.
Payment deadline
PublishedFY2027 tax year is July 1, 2026–June 30, 2027. Annual and first semiannual real-property payments are due September 30, 2026; the second semiannual payment is due December 31, 2026. The 2026 St. Mary's County tax sale was March 6, 2026.
Valuation protest
PublishedAppeal the SDAT assessment within 45 days of the 2026 notice date; Maryland Tax Court appeal is within 30 days of a Property Tax Assessment Appeals Board order. See https://assessmentappeals.dat.maryland.gov/start.aspx.
Do not assume a grace period.
The reviewed record identifies the payment timing above but does not establish a universal penalty schedule for this page. Late charges, interest, collection costs, tax-sale procedures, and lien or foreclosure timelines can depend on state law and the local collector’s process. If the deadline is close or a balance is delinquent, contact the tax collector directly and request the current payoff amount in writing.
Treat a published payment deadline as a hard operational date and retain your receipt or confirmation number.
From assessment to collection
01Valuation and notice
Review the assessment notice as soon as it arrives. The protest window may run from the notice date rather than from the payment due date.
02Statement and account review
Match the tax statement to the parcel or account number and confirm exemptions, assessed value, taxing units, credits, and balance.
03Payment confirmation
Use the official collector channel, then save the receipt, transaction reference, and date posted. A bank submission is not always the same as a county posting date.