Property tax · ZIP 20850
Property tax in Rockville, MD
ZIP 20850 (Maryland) — property tax summary sourced from County assessors. Refreshed on the cadence of the primary regulator with every claim cited to the source record.
What lands here
Pages show the county millage rate, assessment methodology, homestead and senior exemptions, and a link to the assessor's portal for address-specific searches.
Source & refresh
County assessors. Refreshed annual reassessment per county. Stale data is flagged, never silently served. Primary source →
Limitations specific to this source
Top-50 metros covered at launch (~35% of US population). Smaller counties deep-link to the assessor portal with a pending-ingestion flag pending federation.
Maryland context
Chesapeake flood, lead pipes
Maryland has dense FEMA NFHL coverage along Chesapeake Bay tributaries. Baltimore City has extensive LCRR lead-service-line obligations and flagged EPA SDWIS compliance history. Radon Zone 1-2 across most counties.
See Maryland state page for the full state-level rollup across all 12 dimensions.
Read more on property tax
Editorial deep-dives explaining the source data, its limits, and how to read it.
Lead and Copper Rule 2024 — the federal lead-pipe inventory mandate
The 2024 Lead and Copper Rule Revisions (LCRR) require every US community water system to inventory and report lead service lines. Plain-English guide.
Property tax millage — what 'mill' means and how your bill is computed
Plain-English guide to property tax millage rates, assessment ratios, and homestead exemptions. How county assessors compute your annual property tax bill.
School district boundaries — how to confirm yours and why it matters
How school district boundaries work, where to find them, and why the same street can split between two districts.
Deed records — what they show and what they don't
Plain-English guide to county deed records: what gets filed, how to look up a property's history, and why zipradar aggregates only counts (never owner names).
Full dashboard for ZIP 20850
Property tax is one of twelve dimensions zipradar federates per address. See the full federated summary for ZIP 20850:
Open Rockville, MD dashboard →