Understanding the US Property Data Landscape

A comprehensive overview of how property data is collected, stored, and accessed in the United States — from county-level public records to nationwide private aggregators.

The US property data ecosystem is one of the most fragmented in the world. Unlike countries with centralized property registries, the US relies on a patchwork of over 3,100 county recorder and assessor offices, each maintaining their own records in their own format.

How Property Data Is Organized

Property data in the US falls into several key categories: public records (tax assessments, deeds, mortgages), listing data (MLS), valuation data (AVMs and appraisals), geographic data (GIS and parcel boundaries), and environmental data (flood zones, hazards).

Public vs. Private Data

Public records are maintained by county and state governments and are generally available for free or at low cost. However, accessing them at scale requires aggregation from thousands of individual sources. This is where private data providers like ATTOM, CoreLogic, and Regrid add value — they normalize and standardize data from these fragmented sources into unified products.

Key Players

• CoreLogic — covers 99.9% of US properties with tax, deed, and MLS data
• ATTOM Data — 155M+ properties with tax, deed, mortgage, and risk data
• Zillow/Redfin — consumer-facing platforms with valuations and market data
• Regrid — nationwide parcel boundary data from 3,100+ counties
• CoStar — leading commercial real estate data provider

Getting Started

If you are new to US property data, start by identifying your use case. For basic property lookups, county assessor websites are free. For scaled applications, you will need an API provider. Browse our data sources directory to compare options by category, pricing, and data coverage.