A loss run is the official record of a building’s claims history — and to a carrier deciding whether and how to write your apartment building, it is one of the most important documents in the file. Each entry shows a single loss with its date, type, the amounts paid and reserved, and whether the claim is open or closed. Together those entries tell an underwriter how the building has actually performed, which is why learning to read yours is worth an owner’s time.
This is general education for apartment owners, not claims or underwriting advice — your own carrier’s loss-run format and your broker govern your specific file. What follows explains what each column on a loss run means, how an underwriter reads the whole record, and why keeping yours clean and well-documented is one of the most direct ways an owner influences renewal pricing and the availability of an apartment building insurance program.
What a loss run is
A loss run is a report produced by a carrier listing the claims filed on a policy over a defined period — usually several years. It is the documented, official history of what has actually happened at a building, drawn from the carrier’s own records rather than the owner’s memory or description. When you market your building to a new carrier, your loss runs travel with the submission; when you renew, your current carrier is reading them too.
Carriers ask for loss runs because past claims are one of the clearest available signals of future risk. An underwriter cannot inspect every building in person, but a loss run lets them see how a risk has performed — what went wrong, how often, how severe it was, and whether it was resolved. It turns “tell me about the building” into “show me what actually happened,” and that is far more persuasive in both directions.
Reading the columns
The value of a loss run is in its columns, and each one tells the underwriter something specific.
Date of loss is when each claim occurred. Read down the column, it shows frequency — whether losses are spread out or clustered, and whether they are recent or aging out of the relevant window.
Claim type is the nature of each loss: water damage, wind, fire, a liability claim, and so on. The type matters because it points to cause. A scatter of unrelated weather claims reads very differently from repeated losses of the same kind, which can signal an unaddressed building problem.
Paid is the amount the carrier has actually paid out on the claim to date. On a closed claim, the paid figure is essentially final — it is what the loss ended up costing.
Reserved is the amount the carrier has set aside as its estimate of what an open claim may still cost but has not yet paid. The reserve is a forward-looking figure: it signals the carrier’s expectation of where an open claim is headed.
Status is whether each claim is open or closed. A closed claim is settled and done; an open claim is still developing, and an open claim carrying a large reserve is one an underwriter will look at closely, because its ultimate cost is not yet known.
Paid versus reserved, and why it matters
The paid-versus-reserved distinction trips up owners more than any other part of the loss run, so it is worth dwelling on. Paid is money already out the door. Reserved is the carrier’s estimate of money it expects to pay on a claim that is still open. The two are not added together as a final cost — rather, on an open claim, paid plus reserve is the carrier’s current picture of the total, which can move as the claim develops.
This is why open claims draw scrutiny. A closed claim is a known quantity. An open claim with a meaningful reserve is an unknown the next carrier inherits a view of, and it can affect how the building prices until it closes. Owners are sometimes surprised that a claim still showing open years later weighs on their renewal — the reserve is the reason. Getting open claims resolved and closed, where appropriate, is one practical way to clean up the picture an underwriter sees.
How an underwriter reads the whole record
No single entry decides a building’s fate. An underwriter reads the loss run as a pattern, weighing frequency (how often losses happen), severity (how large they are), type (what is causing them), and resolution (whether problems were fixed). A single weather claim on an otherwise clean multi-year record barely registers. A pattern of repeated similar losses — say, recurring water damage — signals something about the building or its operation that has not been addressed, and that is what raises pricing and narrows appetite.
This is also why context is worth presenting alongside the raw report. A loss run handed over with no explanation invites the underwriter to assume the worst. The same loss run presented with a note that the recurring issue was corrected — the plumbing was replaced, the roof redone — tells a story of a problem solved rather than a problem ongoing. The Insurance Information Institute and the National Association of Insurance Commissioners both publish plain-language material on how insurers use claims history in underwriting, useful primary references for owners who want to understand the underwriter’s view.
Real-World Scenario: Two owners shop their buildings in the same season, and both loss runs show three claims over the past few years. The first owner’s three are unrelated — a wind event, a one-off fire in a vacant unit, a minor liability claim, all closed. The second owner’s three are all water-damage claims from the same aging plumbing, one still open with a reserve. To an underwriter, these are not the same risk at all: the first reads as ordinary bad luck on a sound building, the second as an unresolved problem still costing money. The first owner places easily; the second has to explain — and the explanation lands far better when it comes with proof the plumbing was finally replaced and the open claim closed.
Why loss runs matter when buying a building
Loss runs are not only a renewal tool — they are a due-diligence tool. When you are buying an apartment building, requesting the seller’s loss runs during due diligence is one of the most useful pieces of information you can obtain. They reveal whether the building has a quiet history of recurring problems the listing does not mention, and they give you a realistic basis for what the insurance line will cost going forward.
A building with a clean loss history is easier and cheaper to insure than one with a pattern of claims, and that difference flows straight into your operating expenses and your underwriting. Pulling the loss runs before you close is part of lining up the insurance to have in place before you close, and it feeds directly into an honest cash-flow calculation, where the insurance line should reflect the building’s real risk profile rather than a guess.
How loss runs connect to the rest of the program
Loss runs sit at the front of every submission because they shape how every line is priced. The property insurance and general liability lines are quoted in part on what the claims history shows, and a clean record helps across the whole program, not just one coverage. Even the valuation basis a carrier will offer — replacement cost or actual cash value, covered in replacement cost vs. actual cash value for apartment buildings — can be influenced by how the building has performed.
The takeaway for an owner is to treat the loss run as a managed asset, not a passive report. Keep your own copies each year, resolve and close claims where you can, document the corrections you make, and you arrive at every renewal and every refinancing with a record that argues for your building rather than against it.
Keep your record clean and ready
The single best thing you can do with your loss runs is keep them clean and keep them handy. Maintain the building so claims stay rare, document what you fix when a loss does happen, request and file your loss runs each year, and you are always ready to market the risk on favorable terms.
Start with the apartment building insurance overview to see how the lines a loss run prices fit together, and note that the claims profile varies by location — weather-driven losses look different in Florida and Texas than freeze and storm losses in Indiana and Ohio. When you want your loss runs gathered and presented to carriers in their best light, start a quote or reach the agency.