Maryland Property Tax Appeals: 45-Day Deadline & PTAAB

How Maryland Assessment Appeals Work

In Maryland the State Department of Assessments and Taxation (SDAT) values property, and your appeal starts with SDAT, not with the county. There are three levels: the Supervisor of Assessments hearing, the county Property Tax Assessment Appeals Board (PTAAB), and the Maryland Tax Court. SDAT says an appeal can be filed on three occasions: on receipt of an assessment notice, by a petition for review, and on purchase of a property between January 1 and June 30. Maryland SDAT, Assessment Appeal Process

The Deadline: 45 Days From the Notice Date

Owners normally receive a Notice of Assessment every three years, with the old market value next to the new one. To appeal, you file within 45 days of the notice date, either online using the control number on the notice or by returning the paper form to the local assessment office. Count from the date printed on the notice, not the day it reached you. SDAT says it tries to complete reassessment appeals by June 1, depending on volume. Maryland SDAT, Assessment Appeal Process

You can ask for a written appeal, a phone hearing, a video hearing or an in-person hearing.

Petition for Review and Purchase Appeals

In the two years your property is not valued at reassessment, you can file a petition for review by the first working day following January 1. It fits best when something since the last regular assessment has lowered your value. If you did not respond to a Notice of Assessment in time, you may file a petition for the following year. Maryland SDAT, Assessment Appeal Process

If you buy a property that transfers after January 1 but before July 1, you can appeal within 60 days of the transfer. The deed must be recorded in the local land records for the office to go forward. Maryland SDAT, Assessment Appeal Process

What Happens at Each Level

1. Supervisor's level. An informal hearing, typically about 15 minutes, with an assessor designated by the Supervisor of Assessments. SDAT gives you a property worksheet and an Area Sales Listing before the hearing, and you can postpone once.
2. PTAAB. After the final notice from the Supervisor's level, you have 30 days to appeal to the PTAAB. The board is independent of SDAT, with members appointed by the Governor for each county and Baltimore City. There is no fee, and you may bring new evidence. You can appear in person or in writing. Maryland PTAAB
3. Maryland Tax Court. You have 30 days from the date of the PTAAB order. Hearings are de novo, you must be present, and there is no filing fee. Maryland Tax Court

Maryland SDAT, Assessment Appeal Process

What SDAT Says Works

SDAT's own guidance is to focus on the points that affect the value of your property:

• Explain why the Total New Market Value does not reflect market value.
• Point out mathematical errors or wrong property facts on the worksheet, such as bathroom or fireplace counts.
• Provide sales of comparable properties.

SDAT lists what to leave out: comparison to past values, the percent of increase, additional metropolitan costs, the amount of the tax bill, and services rendered or not rendered. Maryland SDAT, Assessment Appeal Process

Homestead Tax Credit

Maryland's homestead credit limits how much of an assessment increase you pay tax on, for the one property you use as your principal residence. It needs a one-time application. New purchasers are mailed an application once the deed is recorded. You can check whether one is on file in SDAT's Real Property search. Maryland SDAT, Homestead Tax Credit

Where the Windows Stand Now

Most Maryland reassessment windows for 2026 have closed. The petition-for-review date for the next year is the first working day after January 1, and the counties we track appear with a countdown in the table above the county list. See the deadlines page for the full list.

Where Grove Hopper Fits

Grove Hopper is a research tool. We look at your property, flag whether it looks over-assessed and prepare your appeal documents. You review, sign and file them yourself with SDAT. We are not attorneys, accountants or a tax firm. The free check is at the top of this page.

Pick your county below for its assessment office, PTAAB and next date.