Maryland Property Tax

Maryland is the only state where the assessment process is centralized at the state level. The State Department of Assessments and Taxation (SDAT) appraises every parcel at 100% of market value and certifies the values to the counties; the counties and Baltimore City set their own rates on top and mail the bills. Real property is reassessed on a three-year cycle, increases are phased in over three years, and the appeal ladder — 45 days, then 30, then 30 — runs from the local Supervisor all the way to the Maryland Tax Court.

In this section

• The triennial cycle and the phase-in — how one-third of each county is reassessed every year, and why a $30,000 increase raises your taxable assessment by only $10,000 a year.
• The Notice of Assessment explained — what arrives in late December, the old and new values it shows, and the date of finality it creates.
• The appeal ladder: 45 days, 30 days, 30 days — the Supervisor, the county PTAAB, and the Maryland Tax Court, including the petition for review and the 60-day new-owner window.
• The 10% homestead cap — the Homestead Property Tax Credit every county must offer, its eligibility rules, and why you apply once, not yearly.
• Maryland property tax deadlines — the assessment cycle, all three appeal windows, the homestead application and the July/August billing season.

Who does what

• SDAT (state) values all real and personal property, runs the triennial reassessment, and directs the major tax-credit programs.
• The Supervisor of Assessments in each county (and Baltimore City) mails the notices, holds first-level hearings, and receives petitions for review.
• The county Property Tax Assessment Appeals Board (PTAAB) is the second-level citizen board.
• The Maryland Tax Court is the top administrative level — appointed judges, no filing fee, and pro se representation is expressly allowed.
• Local governments set the rates, send the bills in July or August, and collect.

The shape of a reassessment

Each county is divided into three reassessment regions, so about one-third of the properties in every jurisdiction are reviewed each year. A reassessment year brings a Notice of Assessment — typically mailed in late December for a January 1 date of finality — showing both the old and the new value. An increase is phased in over three years: the state’s own example has a $30,000 increase adding $10,000 per year to the old value. A decrease takes effect in full at once.

Two consequences matter before you argue about a number. First, the notice value is not the bill: the phase-in spreads the change, and the homestead cap further limits what the tax can do. Second, the two non-reassessment years are not dead years — a petition for review can be filed in any of them (see the appeal ladder).

Finding your property

Maryland has what most states on this site lack: a single statewide official property search. The SDAT Real Property Data Search covers every county and Baltimore City (search is by county plus address or account — owner-name search is deliberately not offered). It is also where the homestead eligibility and phase-in data can be checked.

What this does not cover

County-specific procedures, Baltimore City’s local variations, and the tax-credit programs that sit outside the assessment process are not covered here in detail. AssessCheck has no data connection to SDAT or any county finance office.