*6 min read · Last updated June 23, 2026*
In this article
– Why a claims-made policy cares about two dates, not one – How switching carriers quietly erased five years of coverage – Prior acts and tail coverage: the fix that costs almost nothing – What to check on the declarations page before you sign – FAQ
Marcus Bell runs a six-person IT consulting firm in Columbus. In early 2025 he moved his errors and omissions policy to a new carrier to save $1,400 a year. In March 2026, a former client sued him over a network migration he had finished in 2023, claiming $90,000 in lost revenue. His new policy denied the claim. The work happened before his new policy’s retroactive date, and he had never bought coverage for his earlier years.
Why a claims-made policy cares about two dates, not one
Errors and omissions insurance, also called professional liability, pays to defend and settle claims that you gave bad advice, made a mistake, or failed to deliver a professional service. Most E&O policies are written on a “claims-made” basis. That word matters more than almost anything else in the contract.
A claims-made policy only responds when two things are both true. First, the claim has to be filed against you while the policy is active. Second, the work that triggered the claim has to have happened on or after the policy’s retroactive date. The retroactive date is the start line for your coverage. Anything you did before it is simply outside the policy, no matter how good your record is.
This is the opposite of an “occurrence” policy, which covers any incident that happened during the policy term even if the claim arrives years later. Professional liability is rarely sold as occurrence coverage. So if you carry E&O, assume the retroactive date applies to you. For a deeper breakdown of how this differs from your general liability coverage, see our guide on professional liability versus general liability for small businesses.
How switching carriers quietly erased five years of coverage
Here is the trap Marcus fell into, and it catches careful owners every year.
When you stay with one carrier, that carrier usually keeps your original retroactive date. Each renewal rolls your past years forward, so a claim about work from three years ago is still covered. Your coverage and your work history stay lined up.
When you move to a new carrier, the default changes. Many new policies set the retroactive date to the first day of the new policy, often called “inception.” On paper you still have a $1 million E&O policy. But its start line is now today. Every project you completed before the switch is suddenly uncovered. A client who sues you in 2026 over a 2023 mistake gets met with a denial, because 2023 sits behind your retroactive date.
This is where most professionals silently lose years of protection. The savings on the premium feel real and immediate. The gap is invisible until a claim lands. By then it is too late to fix.
Prior acts and tail coverage: the fix that costs almost nothing
The good news is that protecting your old work is usually inexpensive, and you have two clean ways to do it.
The first option is “full prior acts” coverage, sometimes called “nose” coverage. You ask the new carrier to honor your original retroactive date instead of resetting it. This keeps your years of past work inside the new policy. Carriers grant it routinely when you show proof of continuous prior coverage, and it often adds little or nothing to the premium. The key is that you must ask before the policy is issued. It is not automatic.
The second option is a tail policy, formally called an extended reporting period. You buy it from your old carrier when you leave them. A tail lets you report claims about your old work for a set number of years after the policy ends, often one to six years. Tail coverage costs more, frequently 100% to 300% of your annual premium for a multi-year tail. You generally use a tail when the new carrier will not grant full prior acts, or when you are closing the business entirely. We cover the mechanics of leaving a carrier in detail in our explainer on the claims-made policy tail coverage gap.
In plain terms: full prior acts keeps the new policy looking backward for you. A tail keeps the old policy open for you. You need one or the other when you switch. Going without either is what creates the gap.
What to check on the declarations page before you sign
The retroactive date is printed on the declarations page, the one-page summary at the front of the policy. Pull it out and check three things before you commit, not after.
Check the retroactive date first. It should match your original date from when you first bought continuous E&O coverage, not the new policy’s inception date. If those two dates are different, stop and ask why.
Check whether the policy says “full prior acts.” That phrase, or a retroactive date that reaches back years, tells you the past is covered. A blank field or the word “none” is a warning sign.
Check your limits and how defense costs work, because legal defense can eat into your coverage. On many E&O policies, the money your insurer spends defending you reduces the limit available to pay a settlement. Our piece on how E&O defense costs erode your policy limit walks through how fast that can happen.
FAQ
What is a retroactive date on an E&O policy? It is the start line for your coverage. A claims-made policy only covers work you performed on or after that date. Anything you did before it falls outside the policy, even if the claim is filed while your policy is active.
Does switching E&O carriers cancel my old coverage? It can erase coverage for your past work if you are not careful. A new carrier often sets a fresh retroactive date at the policy’s start, so projects you finished before the switch are no longer covered unless you arrange full prior acts or a tail.
Is prior acts coverage expensive? Usually not. Full prior acts coverage often adds little or nothing to the premium when you can show continuous prior coverage. You have to request it before the policy is issued, because it is not granted automatically.
Can a claim be denied just because of the dates? Yes. If the work that caused the claim happened before your retroactive date, the carrier can deny it on timing alone. A clean claims history and strong facts do not override the date rule.
Do I need a tail policy if my new carrier offers full prior acts? Generally no. Full prior acts on the new policy covers your past work, so a separate tail is usually unnecessary. You buy a tail mainly when the new carrier will not grant prior acts or when you are closing the business.
The day you switch E&O carriers is the day your past work is most exposed. Pull the declarations page, confirm the retroactive date reaches back to when you first bought coverage, and get full prior acts in writing before you cancel anything. A $1,400 saving is not worth leaving years of completed projects uninsured.
