How Reinsurance Cuts Mortgage Insurers' PMIERs Capital by Half

The six private mortgage insurers wrote $76.7 billion of new insurance in the first quarter of 2026, up 32% from a year earlier (Milliman, 1Q 2026 PMI Market Trends), and every one of them reported billions in PMIERs excess capital. At MGIC, though, roughly 52%, or $3.1 billion, of the required-asset figure that excess is measured against exists only because reinsurance moved it off the balance sheet (MGIC, Q1 2026 10-Q). The capital cushion is real. Whether it is entirely MGIC's is a different question.

That distinction, between capital an insurer holds and capital it has arranged to not need, is the actual story behind a quarter that on its face reads as a straightforward volume rebound. Mortgage rates easing into the low 6% range pulled refinance and purchase activity forward, new insurance written (NIW) rose across all six writers, and every company cleared its Private Mortgage Insurer Eligibility Requirements (PMIERs) threshold with room to spare. But PMIERs sufficiency, the ratio regulators and the housing GSEs actually watch, is now a number that reinsurance and insurance-linked notes (ILNs) manufacture as much as retained earnings do. For an actuary pricing mortgage credit risk or reviewing a mortgage insurer's capital adequacy, the reinsurance layer is no longer a footnote to the solvency story. It is a load-bearing part of it.

PMIERs Is Not NAIC Risk-Based Capital, and That Distinction Is About to Bite Harder

PMIERs is a bespoke, bilateral capital standard that Fannie Mae and Freddie Mac impose on the mortgage insurers they accept as counterparties, entirely separate from the NAIC risk-based capital (RBC) framework that governs statutory solvency for the rest of the P&C industry. Under PMIERs, an approved insurer must hold "Available Assets" (largely cash, short-duration investment-grade bonds, and certain reinsurance recoverables) in excess of "Minimum Required Assets," which are calculated using a look-up table of factors applied to each insured loan's risk characteristics: loan-to-value ratio, credit score, loan age, and delinquency status. The ratio of Available Assets to Minimum Required Assets is the PMIERs sufficiency ratio, and it is this number, not statutory RBC, that determines whether Fannie Mae and Freddie Mac will keep accepting an insurer's policies as eligible credit enhancement on loans they purchase (Freddie Mac PMIERs Handbook).

The GSEs revised the Available Asset side of that calculation in 2024, adding exclusions, concentration limits, and new haircuts on the investment assets insurers can count. The changes phase in over 24 months: 25% of the calculated adjustment took effect March 31, 2025, 50% at September 30, 2025, 75% at March 31, 2026, and the full 100% lands September 30, 2026 (MGIC Comments on the Recently Adopted PMIERs Updates). At the time the changes were adopted, MGIC estimated the fully phased-in impact at roughly $50 million, about 1% of its then-$5.8 billion in Available Assets, and projected its PMIERs excess would remain around $2.3 billion once fully implemented (MGIC Comments on the Recently Adopted PMIERs Updates, August 2024). CEO Tim Mattke framed the changes as a positive for counterparty confidence at the time: "We appreciate the collaboration with the GSEs and support prudent PMIERs changes" (MGIC, August 2024).

That 1% estimate was calibrated against a 2024 balance sheet. Two years of phase-in later, the composition of Available Assets across the sector has shifted further toward reinsurance recoverables and structured credit instruments precisely because the industry has leaned harder into risk transfer to manage the same Available Asset calculation the haircuts are tightening. Whether the final quarter of phase-in lands at the originally modeled 1% or something larger depends on how much of each insurer's asset base by September 2026 sits in categories the revised standard treats less favorably, a detail none of the six companies has broken out publicly at the instrument level.

The Math Behind MGIC's 52% Relief

MGIC's Q1 2026 10-Q disclosed PMIERs Available Assets of $5.8 billion against Minimum Required Assets that its reinsurance program had already reduced by $3.1 billion, or approximately 52% (MGIC, Q1 2026 10-Q). Strip the ceded credit away and MGIC's PMIERs excess of $2.9 billion is measured against a required-asset base that is barely half the size it would be on a fully retained basis. The mechanism is a combination of quota share reinsurance (QSR), under which reinsurers assume 90% of the ceded risk on most transactions (80% on MGIC's Credit Union QSR Transaction) and receive full PMIERs credit for the ceded portion, plus excess-of-loss coverage placed through the capital markets, including a $324 million insurance-linked note transaction covering policies written between January 2022 and March 2025 (MGIC, Q1 2026 10-Q).

MGIC is not an outlier. Moody's estimates the sector holds roughly $14.3 billion in current reinsurance and ILN limits across all six PMI companies, built through more than a decade of consecutive issuance: Arch has placed over $8.7 billion through 18 Bellemeade Re transactions since 2015 (with $4.6 billion of current coverage), Essent roughly $3.1 billion through seven Radnor Re deals since 2018 ($2.6 billion current), Radian nearly $3 billion through six Eagle Re deals since 2018 ($2.2 billion current), MGIC nearly $2.3 billion through six Home Re transactions since 2018 ($1.9 billion current), National MI roughly $2.1 billion through seven Oaktown Re deals ($1.6 billion current), and Enact roughly $1.8 billion through five Triangle Re transactions since 2019 ($1.1 billion current) (Moody's, via Artemis.bm). Moody's has cited the arrangements favorably in recent rating actions, characterizing the capital markets capacity as dampening "potential for earnings and capital volatility that has historically impacted the mortgage insurance sector during adverse economic environments" (Moody's, 2026).

The Q1 2026 snapshot across the group shows the same pattern of comfortable headline sufficiency sitting atop varying degrees of ceded risk:

Insurer	PMIERs Available Assets	PMIERs Excess	Sufficiency Ratio	Primary Delinquency Rate
MGIC	$5.8B	$2.9B	—	2.44%
Radian	$5.4B	$1.6B	—	2.51%
Essent	—	$1.6B	174%	—
Enact	—	$1.9B	162%	—

Every one of these ratios is comfortably above the 100% minimum. None of them discloses, in the summary sufficiency figure, how much of the required-asset denominator the company's own reinsurance program has already shrunk. An actuary evaluating counterparty risk on a mortgage insurer, whether for a GSE eligibility review, a rating agency capital model, or a reinsurance treaty negotiated with the insurer itself, has to look past the ratio to the program structure underneath it.

Delinquency Roll Rates Explain More Than the Headline Percentage

The delinquency rates in that table, 2.44% at MGIC and 2.51% at Radian (up from 2.33% a year earlier), look like the leading indicator of reserve adequacy. They are not, by themselves, sufficient. What determines whether a mortgage insurer's loss reserves prove redundant or deficient is the roll rate: the share of newly delinquent loans that cure (return to current status, typically through the borrower resuming payments or refinancing equity out of an appreciated home) versus the share that roll forward into claim. Radian received 13,584 new primary default notices in the first quarter of 2026, up 9% from 12,505 a year earlier (Radian, Q1 2026 10-Q), yet the company's loss provision benefited from favorable reserve development because cures on prior-year defaults ran better than originally estimated, driven primarily by home price appreciation (Radian, Q1 2026 10-Q). MGIC recorded $31 million of favorable reserve development in the quarter for the same reason: delinquency notices received in 2025 cured at better-than-modeled rates (MGIC, Q1 2026 10-Q).

That combination, rising new-notice counts alongside favorable reserve releases, is exactly the pattern a roll-rate reserving framework predicts when home price appreciation is running ahead of the assumptions embedded in an insurer's cure-rate curve. A borrower thirty days delinquent on a loan with meaningful positive equity has a strong economic incentive and a workable mechanism (sale or refinance) to cure before the claim clock runs out. The same borrower with little or negative equity does not. The rising notice count by itself tells an actuary nothing about ultimate loss cost; it is the vintage-level equity position of the delinquent population, cross-tabulated against the cure-rate assumption the reserve was set on, that does. Later-stage cure rates across the industry are running well above pre-pandemic norms, and every quarter that trend persists without a home-price correction is a quarter in which reserves booked on more conservative, pre-pandemic roll-rate assumptions release back to income.

The risk this creates is asymmetric. A reserve methodology anchored to elevated post-pandemic cure rates will look adequate, even redundant, for as long as home prices keep appreciating. It is only tested when appreciation stalls or reverses in a market with a meaningfully larger delinquent inventory than it had a year earlier, at which point the same 9% increase in new notices that looked benign in a rising-price environment becomes the leading edge of a claims wave the reserve was never sized for.

Persistency and Vintage Aging Widen the Earned-Premium Gap

The $76.7 billion in Q1 NIW, up 32% year over year, is a rate-driven story: mortgage rates easing from the low 7% range a year ago to the low 6% range in early 2026 pulled forward both purchase and rate-and-term refinance volume. But NIW growth and persistency cut in opposite directions for premium recognition. Higher persistency, meaning existing policies stay in force longer rather than terminating through payoff or refinance, extends the earned-premium duration of the back book. That is good for near-term revenue. It also means the insured portfolio is aging: the vintages written during the 2020-2022 low-rate origination boom, now four to six years seasoned, represent a larger and more mature share of insurance in force than they would in a market where refinance activity constantly recycled the book into fresh, thinly-seasoned vintages with minimal loss emergence.

Seasoned vintages carry a fundamentally different loss emergence profile than fresh originations. Mortgage credit losses on a given cohort typically peak in years three through seven after origination, once the initial underwriting cushion (down payment, debt-to-income ratio at close) has been tested by several years of potential income shocks, rate resets on any adjustable-rate paper, and changes in local home price trends. A book skewed toward newly-written, thinly-seasoned NIW defers that loss emergence years into the future. A book where persistency has kept 2020-2022 vintages in force defers nothing; those loans are entering their highest-loss-emergence years now, concurrently with the rate-driven NIW surge adding a new layer of unseasoned risk on top. An actuary setting loss reserves or pricing renewal quota share cessions off a blended, undifferentiated persistency assumption will misstate both the earned-premium runoff and the timing of claim emergence, understating near-term reserve needs on the seasoned tranche while overstating them on the fresh one.

What the Reinsurance Dependency Means for Capital Quality

None of this implies the mortgage insurers are undercapitalized. It implies that "PMIERs excess" as a headline figure conflates two different kinds of capital: retained earnings and equity that sit on the insurer's own balance sheet, and required-asset relief manufactured through counterparty arrangements with reinsurers and capital markets investors. The distinction matters for at least three practical reasons. First, counterparty concentration: MGIC's 52% required-asset reduction depends on reinsurers continuing to perform and continuing to renew capacity at economic terms; a reinsurance market that hardens or a reinsurer downgrade cycle would force the insurer to either replace the capacity at a higher cost or hold materially more Available Assets to cover the gap. Second, basis risk: quota share and excess-of-loss triggers are defined by contract language that may not track the insurer's actual loss experience one-for-one across every loan vintage and geography, particularly on the older ILN transactions covering 2022-vintage loans now entering their peak loss years. Third, the September 2026 haircut completion changes what counts as an Available Asset at the same time the industry's reliance on reinsurance recoverables as a component of that Available Asset base has grown, meaning the final phase-in quarter is a genuinely different test than the 1%-impact estimate modeled against a 2024 balance sheet.

For an actuary reviewing a mortgage insurer's capital adequacy, whether from inside the company, from a rating agency seat, or from the GSE counterparty-risk side represented by FHFA's oversight of Enterprise mortgage insurer counterparties, the sufficiency ratio is a starting point, not an answer. The load-bearing question is what fraction of Minimum Required Assets relief comes from a program that could reprice, run off, or face a claims dispute in a stress scenario, versus capital the insurer would still hold if every reinsurance treaty lapsed tomorrow. That fraction, not the headline NIW growth or the comfortable sufficiency ratio, is what actually describes how much economic risk the private mortgage insurance sector is retaining as it heads into the back half of 2026.

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