Howard County, MD Property Tax: Rates, Deadlines & Appeals

If you own property in Howard County, Maryland, your assessed value comes from the state — not the county — and you have two ways to challenge it: appeal within 45 days of your SDAT assessment notice, or file an annual petition for review by the first working day after January 1 (for tax year 2027, that's January 4, 2027). Appeals are filed for free, either online through Maryland's assessment appeals portal or by mail to the Howard County Assessment Office in Ellicott City.

How assessments work in Howard County

Real property in Maryland is valued by the State Department of Assessments and Taxation (SDAT), not by Howard County government. State law requires SDAT to reassess every property once every three years, with the state divided into three rotating cycle groups so roughly a third of properties are reassessed each year. SDAT could not be independently confirmed for which specific group Howard County falls into for the current cycle, so if you're unsure whether this is your reassessment year, check the notice you received or contact the local office directly.

The Howard County Assessment Office is located at the District Court Multi-Service Center, 3451 Court House Drive, Ellicott City, MD 21043 (phone 410-480-7940, email sdat.how@maryland.gov). Whether or not this is your triennial reassessment year, every Maryland property owner may also request a review of their assessment annually through the petition for review process, due by the first working day after January 1 each year.

When SDAT reassesses your property or processes a petition, it mails an official Notice of Assessment. That notice carries two numbers you'll need to file any appeal: a Notice Number at the top of page one and a Control Number at the bottom of page one.

Whether you should appeal

An appeal makes the most sense when your new assessed value looks out of step with what similar homes in your neighborhood have actually sold for recently. SDAT's own Real Property Data Search and Area Sales Analysis tools let you pull comparable sales for your area before you decide whether to file — the same kind of evidence the assessor will expect you to bring to a hearing.

It's also worth appealing if your notice reflects a data error: wrong square footage, a finished basement that isn't finished, a bedroom or bathroom count that's off, or a condition rating that doesn't match reality. These are common, fixable issues that can meaningfully move an assessed value.

Filing costs nothing — SDAT confirms no fee is charged at the Supervisor's level, the Property Tax Assessment Appeals Board, or the Maryland Tax Court. That makes an appeal low-risk for any homeowner who has a genuine case, since the only real cost is your time gathering comparables and attending a hearing.

Step-by-step how to file

1. Find your Notice and Control numbers on page one of your SDAT assessment notice (top and bottom of the page, respectively).
2. File within the deadline that applies to you. If you received a reassessment notice, you have 45 days from the notice date. If you're filing a petition for review outside a reassessment year, submit it by the first working day after January 1.
3. Submit your appeal using SDAT's online appeals portal (assessmentappeals.dat.maryland.gov) with your notice and control numbers, or return the paper form to the Howard County Assessment Office at 3451 Court House Drive, Ellicott City, MD 21043.
4. Gather your evidence — recent comparable sales, photos, repair estimates, or documentation of any data errors on the property record.
5. Attend your Level 1 Supervisor's Hearing. These informal hearings typically run about 15 minutes, and you can request one postponement if the scheduled time doesn't work.

What happens after

If you disagree with the outcome of your Supervisor's hearing, you have 30 days from that decision to escalate to the Property Tax Assessment Appeals Board (PTAAB) — a panel of local residents appointed by the Governor that operates independently of SDAT. You can present evidence in person or in writing, and up to two postponements are allowed at this level.

If you still disagree after PTAAB rules, you have 30 days to appeal to the Maryland Tax Court, the final administrative level. This is a fresh, de novo proceeding — nothing from your earlier hearings carries over — and in-person attendance is mandatory. Beyond the Tax Court, further appeal requires pursuing a judicial appeal with legal counsel.

No fee applies at any of the three levels, and each stage gives you a written decision before the clock starts on your next appeal window.

Local tips

Check your Homestead Tax Credit status even if you're not appealing. It limits how much of an assessment increase is actually taxable each year, and Howard County's local cap is more generous than the state default — Howard County limits the taxable increase on the county portion of your bill to 5% per year, versus the state's standard 10% cap. It's a one-time application filed with SDAT, not the county.

If your household income is at or below $60,000 and net worth under $200,000, look at the state Homeowners' Property Tax Credit, which caps your tax bill relative to income (applied against a maximum assessment of $300,000).

Howard County also runs its own local credits worth checking each year by the October 1 deadline: a Senior Tax Credit (25% off the net county tax for homeowners 65+ with household income at or below $108,200 and net worth at or below $827,200) and an Aging in Place credit (20% off the net county tax, for residents 65+ who've owned and lived in their home 30+ years, or qualifying retired military and disabled veterans).

For a rough sense of what a successful appeal is worth: at Howard County's combined county-plus-state real property rate of about $1.156 per $100 of assessed value (FY2027), reducing an assessment by $25,000 — for example, from $500,000 to $475,000 — saves roughly $289 a year. Combined with the Homestead cap and any credits you qualify for, a data correction or comparable-sales appeal can add up over several years.

Property tax bills are due September 30 for annual or first semiannual installments (delinquent October 1), with the second semiannual installment due December 31 (delinquent January 1). A 0.5% discount applies to the general county real property tax if paid in July.