Underwriting Multifamily Insurance Now That Premiums Fell

Published September 27, 2026

For the first time since 2017, the insurance line on a multifamily underwriting model is more likely to be overstated than understated. Guy Carpenter's United States property catastrophe rate-on-line index was down about 16% for 2026 after the June and July mid-year renewals — the largest annual decline since 2014 — and Howden Re put January 2026 property catastrophe reinsurance down roughly 14.7%. That has flowed through to buyers: Marsh's Q1 2026 index showed global commercial property rates down about 9% in the quarter, and multifamily placements have commonly renewed 5–15% below expiring premiums, per reporting in Commercial Property Executive.

Most models have not caught up. Three hard-market years taught underwriters to take the seller's trailing premium and add 10–20%, and that reflex is now quietly killing bids. The opposite error is available too, and it is the more dangerous one: the premium came down partly because deductibles went up, and retained risk does not appear on any operating expense line.

Why Multifamily Insurance Underwriting Changed in 2026

Multifamily insurance underwriting spent 2020 through 2024 as a one-way trade. Annualized property insurance cost per unit rose from roughly $39 per month in 2019 to about $68 per month in 2024, per National Apartment Association research cited by Multi-Housing News — a figure that is a national average and varies enormously by state, vintage, and construction class. In California, non-high-risk assets that ran $300–$500 per unit annually in 2019 were quoted at $1,800–$2,400 per unit by 2024, per the same reporting.

What changed is capacity, not weather. Capital flowed back into catastrophe reinsurance and insurance-linked securities, competition returned, and the reinsurance savings reached primary placements. Marsh attributed its Q1 2026 property decline to favorable reinsurance terms and a significant oversupply of capacity. Broker commentary quoted in Commercial Property Executive described reinsurance renewal quotes landing near 15% below expiring, with further single-digit declines possible through the balance of the year.

The softening is not uniform. Named-windstorm accounts in Tier 1 coastal zones, California earthquake, and Hail Belt placements have continued to face pressure, and several 2026 market notes describe surplus-lines carriers taking a much larger share of Hail Belt commercial property than they did three years ago. A deal in Kansas City and a deal in Lee County, Florida are not in the same insurance market, and a national percentage applied to either one is a guess — the same geographic split that shows up on the revenue side of a two-speed multifamily market.

The Trailing Premium on the T-12 Is the Wrong Starting Point

The premium on a seller's T-12 statement reflects that owner's program: their loss history, their portfolio scale, their deductible choices, and the date they last renewed. None of that transfers. Insurance behaves less like an escalating expense and more like a property tax reassessment — it resets at closing, sometimes upward and, in 2026, often downward.

That makes the trailing number useful for one thing only: understanding what the asset looks like to a carrier. The underwriting input is a bindable indication from the broker who would actually place the coverage, on the buyer's program, at the deductible structure the lender allows. Where a quote is not yet in hand, carrying a range and modeling the conservative end is more defensible than trending a stale point estimate. This is the same discipline that applies to normalizing a messy T-12 on every other line.

What the Insurance Line Is Actually Worth

Example — illustrative. A 200-unit Class B garden-style property in a Sun Belt secondary market. Purchase price $30M at a 6.0% going-in cap rate, so year-one Net Operating Income (NOI) of about $1.8M. Debt at 60% Loan-to-Value (LTV), $18M, 6.0%, 30-year amortization — annual debt service of roughly $1.30M. Total insured value of $40M. Seller's trailing insurance: $160,000, or $800 per unit.

Three ways the same line gets underwritten:

The spread between the first row and the third is about $32,000 of annual NOI — roughly 1.8% of the total, and somewhere near $500,000 of value once capitalized. On Debt Service Coverage Ratio (DSCR) the move is smaller but not nothing: about 1.39x on the trended premium against roughly 1.42x on the quoted one. These are illustrative figures on assumed inputs; actual quotes vary by carrier, loss history, and roof age.

The point is not that insurance is now a source of return. It is that a line item carried by reflex is being marked at the wrong number in a market where bids are often separated by less than 2% on price.

The Deductible Is Where the Savings Are Hiding

Premium relief in 2026 has frequently come packaged with structure the model does not see. Broker commentary reported in Commercial Property Executive described all-other-perils deductibles that moved from $25,000 to $100,000 during the hard market, and catastrophe perils shifting to percentage deductibles — commonly cited in the 3–5% range of insured value for named windstorm and wind/hail, and materially higher for California earthquake. Some of that has relaxed as the market softened, but the percentage structure itself has largely stayed. The same dynamic runs through other asset classes — see the parallel discussion of insurance and tax lines in park underwriting.

Run it against the example. A 3% named-windstorm deductible on $40M of total insured value is roughly $1.2M of retained exposure per event — about two-thirds of a full year of NOI, sitting entirely outside the operating expense line. A model that books a $144,000 premium and stops there is describing a cheaper program, not a safer one.

Two practical consequences. First, the retained layer is worth carrying somewhere in the model — as a funded reserve, a sensitivity, or at minimum a disclosed assumption in the Limited Partner (LP) materials. Second, deductible choice is not fully free: agency lenders set coverage and deductible parameters in the Fannie Mae Multifamily Selling and Servicing Guide and Freddie Mac's Multifamily Seller/Servicer Guide, and those terms are revised periodically. Verify current requirements directly with the lender before assuming a high-deductible program is available on the debt being quoted.

Where This Breaks

The honest counter-case is straightforward, and it has three parts.

Insurance is cyclical, and this cycle is young. Guy Carpenter's index is still up roughly 66% from the 2017 market bottom even after the 2026 decline, which means current pricing is a partial retracement of a very large increase, not a return to pre-hard-market levels. Underwriting a soft-market premium flat across a five-year hold assumes a market condition that a single severe catastrophe season could reverse. A stress case that reflates the insurance line meaningfully by the exit year is cheap to run and occasionally decisive.

Rate is not premium. A carrier can cut rate while total insured value rises on replacement-cost revaluation, and the owner writes a similar check. Valuation scrutiny has been a persistent theme in 2026 market commentary, so a quoted percentage decrease should be checked against the actual dollar bind.

And softening is a market-level statement, not a property-level one. Frame construction with an aging roof in a hail-exposed county, or an asset with two recent water losses, can renew up in a year when the index is down. The national number is context for the conversation with the broker, not a substitute for the quote.

The Underwriting Takeaway

Multifamily insurance stopped being a line you escalate and went back to being a line you price. Three things follow: replace the trailing premium with a bindable indication rather than trending it, carry the retained deductible layer somewhere visible instead of letting the premium decline flatter the model, and stress the exit-year premium as though the cycle turns — because insurance cycles have historically done exactly that.

The sponsors who get this right in 2026 are unlikely to be the ones who assumed the softest quote. They are more likely to be the ones whose model still works when the quote comes back where the seller's did.

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This analysis reflects current market interpretations as of the publication date and may evolve as new data becomes available. Figures cited are drawn from public sources including Guy Carpenter and Howden Re reinsurance renewal data reported by Artemis, Marsh's Q1 2026 Global Insurance Market Index as reported by Commercial Property Executive, National Apartment Association research reported by Multi-Housing News, and the Fannie Mae and Freddie Mac multifamily guides, and are subject to revision. Nothing in this post is investment advice; readers should conduct their own diligence and consult qualified professionals before making investment decisions.