Maryland · St. Mary's County · Local exemptions · Updated Oct 2026
St. Mary's County, MD property tax exemptions (2026)
The property tax breaks that are set or run locally in St. Mary's County, on top of Maryland’s statewide rules: what each is worth here, who qualifies, where to apply and the deadline.
What is different in St. Mary's County
St. Mary's County offers three senior credits on one county application: a 'Matching' credit that doubles the state Homeowners' credit for owners 70+, a 'Cap' credit that freezes county tax for owners 70+ with taxable income up to $80,000, and a '65-10' credit of 10% for long-time owners or military retirees 65+. The county Homestead cap is 3% (Leonardtown 10%).
Apply at
St. Mary's County Treasurer's Office
Phone
301-475-4200 ext. 3300
Local breaks
Homestead Property Tax Credit (local cap), County Senior 'Matching' Tax Credit, County Senior 'Cap' Tax Credit, County Senior '65-10' Tax Credit
Tax year
2026-27
Where to apply in St. Mary's County
St. Mary's County Treasurer's Office
Phone
301-475-4200 ext. 3300
Address
23150 Leonard Hall Drive, P.O. Box 642, Leonardtown, MD 20650
St. Mary's County tax: the taxable assessment on your home can rise at most 3% a year; State tax: 10% a year. You pay no tax on the part of an increase above the cap. Towns with a different cap for town tax: Leonardtown 10% (see the table).
Set by
state program, local amount
Tax year
2026-27
Who qualifies
Owner-occupants of their principal residence; no age or income limit.
How to apply
One-time application to SDAT (online at Maryland OneStop / sdathtc.dat.maryland.gov, or the paper form). Check SDAT Real Property Search first: if it shows 'No Application', apply.
Age 65+ by July 1 and either on the deed of the home 40+ years or a retired active-duty military member; home assessed under $400,000; home not in a living trust.
Income limit
Household taxable net income of $80,000 or less.
How to apply
County Consolidated Senior Tax Credit Application (deed or DD-214 required).
Roughly what an exemption could save you a year: the value it takes off, times your tax rate.
Eligibility finder for St. Mary's County
Answer a few questions to see which property tax breaks may fit you. Nothing you type here is sent anywhere.
Document checklist for St. Mary's County
Pick the breaks you plan to apply for. You get a checklist of forms, documents, steps and deadlines to print or keep on your phone.
Questions about property tax exemptions in St. Mary's County
What property tax exemptions are there in St. Mary's County?
St. Mary's County offers three senior credits on one county application: a 'Matching' credit that doubles the state Homeowners' credit for owners 70+, a 'Cap' credit that freezes county tax for owners 70+ with taxable income up to $80,000, and a '65-10' credit of 10% for long-time owners or military retirees 65+. The county Homestead cap is 3% (Leonardtown 10%). Local breaks here: Homestead Property Tax Credit (local cap); County Senior 'Matching' Tax Credit; County Senior 'Cap' Tax Credit; County Senior '65-10' Tax Credit.
Where do I apply for a property tax exemption in St. Mary's County?
St. Mary's County Treasurer's Office Phone: 301-475-4200 ext. 3300 Address: 23150 Leonard Hall Drive, P.O. Box 642, Leonardtown, MD 20650. Also: Maryland Department of Assessments and Taxation (SDAT) – Tax Credit Programs, which state program: Homestead and Homeowners' tax credits (and county supplements run through the HTC form). Also: SDAT St. Mary's County Assessment Office, which SDAT local assessment office: assessments, disabled-veteran and blind exemptions.
When is the deadline to apply in St. Mary's County?
Homestead Property Tax Credit (local cap): not confirmed; ask the office. County Senior 'Matching' Tax Credit: May 1 to be on the printed bill; September 1 final. County Senior 'Cap' Tax Credit: September 1 (May 1 to be on the printed bill). County Senior '65-10' Tax Credit: September 1.
Is there an income limit for St. Mary's County’s local breaks?
Homestead Property Tax Credit (local cap): no income limit listed. County Senior 'Matching' Tax Credit: Gross income under $60,000 (state HTC). County Senior 'Cap' Tax Credit: Household taxable net income (Maryland Form 502) of $80,000 or less. County Senior '65-10' Tax Credit: Household taxable net income of $80,000 or less.
Do I have to reapply every year in St. Mary's County?
Homestead Property Tax Credit (local cap): One-time application. County Senior 'Matching' Tax Credit: Every year. County Senior 'Cap' Tax Credit: Every year. County Senior '65-10' Tax Credit: Every year; maximum 5 years.
Good to know in St. Mary's County
Only one county senior credit is applied to an account each year; the Treasurer picks the most valuable one.
Senior credits apply to county tax only, not State tax, fire/rescue/emergency services taxes or fees.
Median effective tax rate for St. Mary's County: U.S. Census Bureau, American Community Survey, 2020–2024 5-year estimates, county figures as published by Tax Foundation. The rate is property taxes paid divided by home value.