The supplemental window
18 months from date of loss, so as long as you're within that window, a supplemental is procedurally viable.
What a PA reviews
- Scope missed on the carrier's estimate
- Depreciation that was improperly applied
- Matching-statute issues
- ALE / business interruption undervaluation
- Code-upgrade coverage not applied
The tradeoff
If you've already cashed a check and accepted the settlement in writing as final, the supplemental path is harder but not impossible.