Firms want a single price for E&O, and the coverage never gives one cleanly. The premium is built from what you do, how much you bill, your claims history, and the structure you choose. The honest way to get a number is a quote built on your actual operation. What follows is what moves that number and why, ranked from the drivers that weigh most to the ones that quietly matter more than owners expect.
Profession and practice area
This is the largest input. Carriers group professions into risk classes based on how often the work leads to claims and how expensive those claims tend to be. An advisory practice that touches money, legal exposure, or safety sits in a different tier than one that does not. Two firms with identical revenue can price far apart on practice area alone, because the mechanism is claim frequency and severity, not headcount. This driver is mostly fixed, but describing your practice area accurately keeps you from being rated for work you do not do.
Revenue
Revenue is the scaling factor. It stands in for how much work you produce and therefore how much exposure you create over a year. More billings generally means more engagements, more deliverables, and more chances for a mistake that leads to a claim. Because revenue drives the rating, it is also the number a carrier will confirm at audit, which is why an estimate that runs low can come back as a true-up.
Services performed
What you actually do inside your practice area refines the number. A firm that only advises is a different risk than one that also implements, designs, or signs off on work for others. The broader and more hands-on the services, the more ways a client can allege harm. This is a driver you influence directly through an accurate application. A services description that is broader than reality quietly raises your cost, and one that is too narrow can leave a gap.
Claims history
History follows the account. Prior claims, and even reported incidents that never became claims, tell a carrier something about future risk. A clean record earns better treatment over time, and a rough one raises the number until it ages off. This driver rewards patience and good documentation, because how you present and explain past matters affects how an underwriter reads them.
Limits and deductible
The structure you choose moves the price in both directions. Higher per-claim and aggregate limits mean the carrier is standing behind more, so they usually cost more. A higher deductible or retention shifts some of the first-dollar risk back to you and can lower the premium, subject to your policy terms. The right structure is the one that satisfies your contracts and your real exposure, not simply the cheapest combination.
Retro date and years in business
The retro date sets how far back your claims-made coverage reaches. A firm with a mature retro date is covered for years of past work, and that continuity has value. Time in business also signals stability. These are not the loudest drivers on the quote, but they shape the account.
Prior-acts continuity
This is the driver owners underrate most. When you switch carriers, preserving your prior-acts coverage keeps your past work protected under the new policy. Break that continuity and you may be forced into nose or tail coverage to fill the gap, which adds cost and complexity. Handled well, continuity is invisible. Handled badly, it becomes the most expensive surprise in the file.
Questions to ask your advisor
- Is my E&O rated for the practice area and services I actually perform today?
- Is my revenue figure current, or am I exposed to an audit true-up?
- Are my per-claim and aggregate limits sized to my contracts and real exposure?
- Will switching carriers preserve my retro date and prior-acts coverage?
- How is my claims history being weighed, and how do I present it well?
A coverage review looks at both sides: that you are not overpaying for services you do not perform, and that you are not underinsured against the exposure you actually carry.
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