California's Sustainable Insurance Strategy: What It Means for Insurers and How to Operate Under It

Under Insurance Commissioner Ricardo Lara's Sustainable Insurance Strategy, California's Department of Insurance (CDI) prices wildfire risk against CDI-approved catastrophe models rather than a rolling twenty-year average of historical losses. Commissioner Lara announced the reform package in September 2023, CDI finalized the underlying regulations in December 2024, and the strategy took full effect on January 1, 2025. None of that is breaking news at this point. What matters now, well into the second year of implementation, is what California's Sustainable Insurance Strategy actually requires of insurers writing or considering California business, and how to operate under it without getting caught flat-footed by the parts that are easy to overlook.

What California's Sustainable Insurance Strategy Changed, in Brief

For decades, California barred the use of forward-looking catastrophe models in ratemaking, which meant wildfire risk got priced off historical averages even as fire seasons grew longer and more destructive. That constraint is gone. CDI opened a formal review of wildfire catastrophe models in January 2025 and, by August 1, 2025, had cleared three of them for use in rate filings. Those models, along with five other mechanisms the strategy put in place, now define how wildfire risk gets priced, discounted, and covered across the state.

The Six Mechanisms Insurers Are Operating Under

Here is what each one requires and why it matters operationally, not just as a compliance checkbox.

A. Catastrophe Modeling in Rate Filings

CDI-approved wildfire catastrophe models account for mitigation and home hardening, not just historical loss patterns, which means a property with defensible space and an upgraded roof can be priced differently than an identical unmitigated home next door. For underwriting teams, that is a real pricing lever tied to actual property condition, not a box to check once and forget.

B. Reinsurance Cost Passthrough

Carriers can incorporate a share of California-specific net reinsurance costs into their rates when they expand coverage in distressed areas, under a mechanism CDI finalized in December 2024. This financial piece makes expanding into higher-risk ZIP codes viable for a carrier rather than a straightforward loss leader, and it is worth modeling explicitly into any California growth plan.

C. The 85 Percent Market Share Commitment

Insurers that use CDI-approved models and the reinsurance passthrough mechanism commit to writing at least 85 percent of their statewide market share in CDI-designated distressed ZIP codes. It is worth saying plainly that Consumer Watchdog has pointed out there are limited enforceable penalties if a carrier falls short of that commitment, so the 85 percent figure functions more as a condition of access to the pricing tools than a guaranteed outcome, and portfolio planning should treat it that way.

D. Safer from Wildfires Mitigation Discounts

Insurers must provide clear, quantifiable discounts and rate credits to homeowners and businesses that complete qualifying mitigation: upgraded roofing and windows, defensible space maintenance, Firewise USA community membership, and Fire Risk Reduction Community designation. Consumers are also entitled to see their property's wildfire risk score and to appeal it. This is a filed rate obligation, not a marketing gesture. Hence, an insurer needs a way to actually verify that a roof upgrade or brush clearance happened at the parcel level, or it cannot administer the discount it is required to offer.

E. The FAIR Plan's Expanded Role and Oversight

California's FAIR Plan, the state's insurer of last resort, now carries higher coverage limits, coverage for manufactured homes, and tighter financial transparency and oversight requirements, along with financing tools such as bond issuance through IBank. The FAIR Plan has requested rate increases exceeding 35 percent, and the state's explicit goal is to shrink the FAIR Plan's footprint by moving policyholders back into the voluntary market as carriers take on the 85 percent commitment. FAIR Plan growth is a symptom of an underserved market, not a strategy, and the insurers moving fastest right now are the ones building the capacity to write that business on their own paper instead of watching it accumulate.

F. Non-Renewal Moratoriums

When the Governor declares a state of emergency, residential policies within or adjacent to the fire perimeter are protected by a mandatory one-year moratorium on cancellation or non-renewal, building on protections the Department says have covered millions of Californians since 2019. Portfolio and claims systems need a trigger that flags affected policies the moment an emergency is declared. Missing this is not a rounding error; it is a compliance failure for a real policyholder on the other end.

Where Prediction Still Falls Short

California's Sustainable Insurance Strategy rests on the premise that forward-looking prediction beats a static historical score, and that premise is sound. But CDI-approved models are not the final word on wildfire risk. Their review process relied on non-disclosure agreements that keep vendor methodology out of public view, and the approved models do not produce identical scores for the same property. We'll go deeper on these limitations in a future companion piece, Compliant Does Not Mean Certain: What CDI-Approved Wildfire Models Still Get Wrong. The short version here: treat an approved model's score as a strong input, not a verdict, and build a practice around triangulating across data sources rather than trusting a single vendor's number by default.

Operating Under the Strategy: What It Actually Takes

Staying aligned with California's Sustainable Insurance Strategy day-to-day means underwriting has shifted from a single, static score per property to a maintained, updatable risk profile that reflects current mitigation status rather than census-tract history alone. Rate filings need to show the regulator the model's methodology and mitigation credit logic, so actuarial and underwriting teams need documentation they can defend, not a black box they cannot explain either. Portfolio strategy must treat the 85 percent commitment as a binding constraint built into growth targets and reinsurance purchasing from the outset, not bolted on after a filing is approved. Discount administration must be a real operational capability, since verifying a roof upgrade or defensible space at parcel scale, at the volume Safer from Wildfires requires, is a system to build, not a policy to announce. Emergency response workflows need an automatic trigger tied to the Governor's declarations, so the non-renewal moratorium applies correctly across the full affected footprint without manual intervention. And FAIR Plan exposure needs active management, since depopulation is a stated state goal, and the carriers moving fastest are the ones building the underwriting capacity to take that business onto their own paper.

The Cost of Standing Still

None of this carries a dramatic penalty for inaction, and it is worth saying that plainly rather than overselling the urgency. Carriers that price purely on historical data simply lose the ability to compete on the same rate flexibility as carriers using CDI-approved models, which tends to show up as overpricing safe, well-mitigated homes or underpricing risk that has quietly worsened. Staying outside the strategy's framework means forgoing the reinsurance passthrough tool and the pricing flexibility that comes with it, while carriers who opt in gain both a growth mandate and a pricing edge in the same ZIP codes. Getting Safer from Wildfires or non-renewal moratorium administration wrong is a real compliance exposure with an actual policyholder behind it, not an abstract risk. And continued reliance on the FAIR Plan as a release valve is a shrinking option, since the state's explicit goal is depopulating it and carriers like CSAA are already doing exactly that in Northern California. This is a market share and margin conversation. The tools exist; the early movers are already filing, and waiting is itself a strategic choice with a cost attached to it.

What to Look for in a Technology Partner

Aligning with California's Sustainable Insurance Strategy into practice comes down to a short list of capabilities worth demanding from any modeling or data partner. Compliance-grade transparency matters most: the underlying risk scoring should be explainable and defensible to a regulator, not just to a marketing team, and ideally able to help reconcile the divergence between vendor models rather than simply adding a fourth opinion. Forward-looking, mitigation-aware modeling needs real verification, since Safer from Wildfires discount administration depends on confirming that a claimed mitigation really happened, not just crediting a homeowner's word. A platform that fuses multiple data signals, structural, environmental, financial, and behavioral, at the parcel level will reflect the actual property rather than a ZIP code average or a single vendor's black box; parcel-level wildfire intelligence built for continuous monitoring reflects current conditions rather than a point-in-time snapshot. Wildfire is the immediate driver of this regulation, but a durable underwriting infrastructure should also cover earthquake and other major perils at the portfolio level, since the goal is one system that flags concentration risk across hazards rather than a separate tool rebuilt every time a new peril becomes a regulatory priority; catastrophe modeling and hazard scoring built to work this way gives compliance and underwriting teams a defensible answer when a regulator asks how a score was reached. Round it out with operational readiness for the consumer-facing rules, meaning automated flagging for non-renewal moratorium zones and a defensible audit trail for discount eligibility, and speed, since the 85 percent commitment only helps if a team can actually price and bind in distressed ZIP codes without manual data collection slowing everything down.

Where This Leaves Insurers

California's Sustainable Insurance Strategy is not a headline anymore, it is the operating environment. The insurers doing well under it are the ones treating it as an underwriting and technology decision rather than a one-time compliance project, and who stay honest about where even CDI-approved prediction still has real limits. If you want to talk through how this applies to your specific portfolio, our property and casualty team is a good place to start.