Appraisers generally prefer comparable sales from roughly the last six months. They can reach back further, but the older the sale, the more likely it needs a time adjustment for market movement. And if a nearby home sold recently at a lower price, they usually will not skip it to grab an older, higher sale, because they are documenting the recent trend. A typical appraisal includes several comps, often around three primary plus three additional, and those comps have to bracket your property on the high and low side while supporting the local trend. That bracketing lets an underwriter see the appraiser is not cherry-picking. Automated review tools now score appraisals for quality and confidence and flag issues, which sometimes sends the appraiser back to explain why they chose the comps they did. If you think a value came in wrong, the productive move is supplying better, more recent comparable sales rather than arguing the number itself.