There is no legal limit on how far back a retroactive appraisal can go. Appraisal standards allow an effective date at any point in the past, and appraisers regularly complete assignments with effective dates one, five, or even ten or more years back. The practical limit is data. The appraiser needs reliable records of comparable sales from around the effective date, and MLS systems, public records, and market reports in most areas preserve that data for decades. What gets harder over time is documenting the property’s condition as of the past date, since renovations, damage, or additions may have occurred since. Photographs, permits, and family records help fill those gaps. Long look-back periods come up more often than people expect, usually when an heir sells inherited property years after a death and a CPA asks for basis documentation that was never obtained. Older assignments may take more research, but they are routine work for appraisers experienced in estate valuation.
