Insurance

Medical Loss Ratio — Quarterly Trend

Medical Loss Ratio (MLR) = the share of every premium dollar health insurers spend on actual medical care (rather than admin or profit). The ACA requires at least 80-85% — below that, insurers must rebate the difference. Higher MLR = more spent on care; very high = margin pressure. Quarterly for the 6 largest US health insurers.

Medical Loss Ratio = medical benefits expense / premium revenue. Lower is better for the insurer. HUM and CNC pushed above 91% during the 2024-2025 utilization shock driven by Medicare Advantage cost inflation; UNH followed in mid-2025. Source: 10-Q / 10-K filings, earnings supplements.

The UnitedHealth Collapse

UNH stock price and forward P/E (price ÷ next-12-month consensus earnings — the standard valuation multiple) from Jan 2024 to May 2026. Three sequential shocks erased ~$330B of market cap: Brian Thompson killing (Dec 2024), Q1 2025 earnings miss + pulled guidance, Optum DOJ probe (May 2025). Forward P/E compressed from ~21x to below 10x before slow recovery.
Dec 2024Brian Thompson killed (Dec 4)
Apr 2025Q1 earnings miss + guidance pull (Apr 17)
May 2025Optum DOJ probe disclosed (May 14)
May 2025Trough ~$280
Mar 2026Recovery to ~$340

UNH dropped from $610 in Nov 2024 to ~$280 in May 2025 — a $330B+ market-cap evaporation — driven by sequential catalysts: CEO assassination, Q1 2025 earnings miss + guidance pull, and the DOJ Optum/Medicare Advantage probe. Forward P/E compressed from ~21x to below 10x. Sources: Yahoo Finance, FactSet consensus.

Medicare Advantage Enrollment by Carrier

Medicare Advantage (MA) is the private-insurer version of Medicare — seniors pick a plan from UnitedHealth, Humana, etc. instead of traditional government Medicare, and CMS pays the insurer a per-member subsidy. Annual enrollment by carrier, 2020-2026. Total MA grew from 24M to 36M+ as Boomers aged in; this is the most profitable line for the major health insurers.

US Medicare Advantage enrollment by parent organization. Total MA enrollment grew from ~24M (2020) to ~36M+ (2026E) as Boomers aged in and CMS subsidies expanded. UNH and Humana lead but Humana intentionally shed ~600K members in 2025-2026 after its 4-star+ contract share collapsed. Source: CMS Monthly Enrollment by Contract.

STAR Ratings Distribution

STAR Ratings are CMS quality scores (1-5 stars) for Medicare Advantage plans. Plans rated 4 stars or higher get bonus payments from the government — often 5%+ of premium — and members preferentially enroll. 2025-rating-year distribution by carrier. Humana's 4-star+ share collapsed from 94% to 25%, triggering ~$3B in lost bonus payments and the company's 2024-25 crisis.
CarrierMA Members% in 4-star+ (2024)% in 4-star+ (2025)YoY54.543.53<3
UnitedHealthUNHDropped from 87% to 78%; modest revenue headwind
10.1M87%78%-9pp1518123
HumanaHUMLost ~$3B in QBP starting 2026; lawsuit filed against CMS; Mar 2025 ruling vacated cut-points but bonuses for 2026 already lost
5.7M94%25%-69pp1361141
CVS/AetnaCVSBest-performing large MA portfolio in 2025; minimal QBP impact
4.3M87%81%-6pp141162
ElevanceELVFiled lawsuit; 23pp decline
2.2M64%41%-23pp1594
CenteneCNCOnly major carrier to improve materially YoY; turnaround under new CEO
1.3M22%55%+33pp14631
MolinaMOHSmall MA footprint; Medicaid-focused
250K50%35%-15pp372
Clover HealthCLOVSmall but high-quality MA portfolio; PPO plan rated 4-star
80K80%90%+10pp111
Oscar HealthOSCRACA-marketplace pure-play; exited MA after 2023

% in 4-star+ drives Quality Bonus Payments (QBP) under MA. Humana's collapse from 94% to 25% triggered a ~$3B annualized QBP loss starting 2026 and was the central catalyst for the company's 2024-2025 crisis. Centene was the sole major carrier with meaningful YoY improvement. Source: CMS MA STAR Ratings 2025 plan year.

Days Claims Payable — Reserve Snapshot

Days Claims Payable (DCP) = unpaid claim reserves ÷ daily claims expense. Measures how many days of medical claims the insurer could cover from money already set aside. Healthy range is 40-60 days; lower = thinner cushion if claims spike, higher = conservative reserving. Snapshot at Q1 2026.
DiversifiedACA-focusedMedicaid-focusedMA-focused

Days Claims Payable measures how long the insurer can cover medical claims from reserves on hand. Industry healthy range is 40-60 days. Lower-DCP carriers (HUM, CLOV) have less cushion if claims surge; Cigna and Oscar are most conservatively reserved. Source: Q1 2026 10-Q filings.

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