Appraisal, CMA, or Zestimate — what's the difference?

An automated valuation model — a Zestimate or similar — is a statistical estimate produced from public records and prior sales. No one has seen the property. No one is liable for the number. It cannot be used for tax, court, lending, or insurance purposes.

A comparative market analysis is prepared by a real estate agent, usually free, to support a listing or offer strategy. It reflects genuine local market knowledge, but it is produced by someone whose compensation depends on a transaction occurring. It is a marketing opinion, not an independent one.

An appraisal is an independent, USPAP-compliant opinion of value prepared by a licensed professional who inspected the property, is paid a flat fee regardless of the conclusion, and can be required to defend that conclusion under cross-examination.

Each has a legitimate use. The mistake is bringing the wrong one to a proceeding that requires the other — arriving at a divorce hearing or an IRS review with a CMA, and discovering it carries no weight at all.