If you carry real estate E&O, it is almost certainly written on a claims-made basis, and that single fact shapes whether a claim on an old transaction is covered. The distinction between claims-made and occurrence sounds like jargon until a demand letter arrives on a deal that closed years ago. Here is what actually matters.
The core difference
An occurrence policy responds to incidents that happen during the policy period, no matter when the claim shows up. A claims-made policy responds to claims first made while the policy is active, for work done after a retro date. Because real estate claims often surface long after closing, nearly all E&O is claims-made, which puts the focus on continuity rather than just having a current policy.
Why the retro date decides everything
The retro date is the line in time before which your work is not covered. A policy can be in force today and still deny a claim on a transaction that predates the retro date. That is the trap that catches professionals who assume an active policy covers their whole history. It does not; it covers work back to the retro date and no further.
The carrier-switch risk
Changing E&O carriers is where coverage quietly disappears. If the new policy carries full prior acts back to your original retro date, you are protected. If it resets the retro date later or excludes prior acts, years of past transactions can fall into a gap, often to save a small amount of premium. Always confirm prior acts before you move, and treat the retro date as something to protect, not trade.
Tail coverage and exits
When you retire, sell the firm, or change careers, a claims-made policy stops covering new claims the day it ends, even on work you already did. Tail coverage, an extended reporting period, keeps the door open for claims that surface later. It is easy to overlook at exactly the moment it matters most. A quick coverage review confirms your retro date, prior acts, and whether you need tail.