Healthcare is the largest sector in the US economy — accounting for nearly 18% of US GDP and generating over $4.5 trillion in annual spending. The sector spans an enormous range of business models: health insurance (managed care), hospital systems, medical devices, diagnostics, pharmacy benefit management, specialty pharmaceuticals, and health IT.
Understanding healthcare investing requires understanding the distinct economics of each sub-sector. A health insurer’s value driver is medical loss ratio management; a hospital’s is patient volume and reimbursement rates; a medical device company’s is innovation and procedure volume. These are structurally different businesses that happen to share a sector label.
Healthcare Sub-Sectors and Revenue Models
Managed Care / Health Insurance
Health insurers (UnitedHealth, Elevance, CVS/Aetna) collect insurance premiums from employers, governments, and individuals, then pay claims when members receive care.
The key profitability metric is the medical loss ratio (MLR) — the percentage of premium revenue paid out in medical claims. Commercial managed care runs MLRs of 80–86%; Medicare Advantage plans target similar ratios. A 1-percentage-point change in MLR moves earnings per share significantly.
Managed care companies have evolved beyond pure insurance into vertically integrated health platforms — UnitedHealth owns Optum (pharmacy benefits, analytics, physician practices), generating 40%+ of group revenue from non-insurance sources.
Hospital Systems / Health Systems
Hospital operators (HCA Healthcare) earn revenue from patient services: inpatient admissions, outpatient procedures, emergency care, and specialty services. Reimbursement comes from commercial insurers, Medicare, and Medicaid — at rates that vary enormously (commercial = highest, Medicaid = often below cost).
Hospital profitability is driven by payor mix (more commercial, less Medicaid), procedure volume, staffing cost control, and supply chain efficiency. Outpatient procedure migration — from inpatient to outpatient settings — is a long-run structural trend that benefits surgical centres and compresses inpatient volumes.
Medical Devices and Diagnostics
Medical device companies sell equipment (MRI machines, surgical robots), implants (pacemakers, hip replacements), and diagnostics (laboratory tests, molecular diagnostics) to hospitals, clinics, and laboratories.
The business model is often razor-and-blades: sell the device or instrument at cost (or a discount), then earn high-margin recurring revenue from the consumables, reagents, and services that attach to it. IDEXX Laboratories epitomises this model — instruments placed in veterinary clinics generate recurring reagent revenue at 55–60% gross margins.
Pharmacy Benefit Management and Specialty Pharmacy
PBMs (CVS Caremark, Express Scripts) administer drug benefit programmes for employers and health plans, negotiating drug prices with manufacturers and dispensing medications through retail or mail pharmacies. CVS Health uniquely integrates insurance (Aetna), PBM (Caremark), retail pharmacy, and health clinics.
Revenue Models Compared
| Sub-Sector | Revenue Basis | Key Margin Metric |
|---|---|---|
| Managed care / insurance | Premium revenue | Medical loss ratio (target 82–86%) |
| Hospital systems | Patient service revenue | EBITDA margin (8–15%) |
| Medical devices | Equipment + recurring consumables | Gross margin 55–70% |
| Diagnostics / lab | Test volume × reimbursement rate | Gross margin 40–55% |
| PBM / specialty pharmacy | Prescription volume + admin fees | Low gross margin, high volume |
Key Companies in Healthcare
- UnitedHealth Group — largest US health insurer + Optum; revenues exceeding $370 billion
- Elevance Health — major managed care company (formerly Anthem); Blue Cross Blue Shield affiliates
- CVS Health — integrated pharmacy, PBM, and insurance (Aetna); drugstore retail
- HCA Healthcare — largest US for-profit hospital operator; 186 hospitals
- Abbott Laboratories — medical devices, diagnostics, nutritional products, branded generics
- Johnson & Johnson — MedTech (cardiovascular, orthopaedic, vision); pharmaceutical business
- IDEXX Laboratories — veterinary diagnostics and software; instruments + consumables model
- IQVIA Holdings — healthcare data analytics and clinical research services
- Hims & Hers Health — telehealth platform; GLP-1 compounding; subscription wellness
Key Metrics for Healthcare Companies
Medical Loss Ratio (MLR) — Managed Care
The ratio of claims paid to premium earned. Commercial managed care targets MLR of 82–85%; if MLR rises above this (rising utilisation, pandemic catch-up care), earnings guidance gets cut. MLR is the single most important number in managed care earnings.
Same-Hospital Admissions Growth — Hospital Systems
Organic patient volume growth at existing hospitals. Adjusted admissions (inpatient + outpatient adjusted for average revenue per case) measures volume more accurately than raw admission counts. HCA’s strong execution typically produces same-hospital adjusted admission growth of 2–4% annually.
Recurring Revenue Ratio — Medical Devices
For device companies, the percentage of revenue from consumables, reagents, and service contracts vs capital equipment sales. Higher recurring revenue ratios mean more predictable, higher-margin revenue. IDEXX targets 80%+ recurring revenue.
Gross Margin
Highly variable by sub-sector. Medical device gross margins (55–70%) are far superior to hospital operating margins (8–15%). Understanding which type of healthcare business you’re analysing is essential for interpreting gross margin.
Days Sales Outstanding (DSO)
Healthcare companies often have complex, slow-moving payment cycles — billing insurers, government programmes, and patients requires adjudication. High DSO relative to peers signals billing complexity or collection issues.
The ACA, Medicare Advantage, and Regulatory Risk
US healthcare is uniquely policy-dependent. The Affordable Care Act created the individual insurance exchanges and expanded Medicaid — both important volume drivers for managed care. Medicare Advantage (private insurance for Medicare beneficiaries) has grown from 25% to nearly 50% of Medicare enrolment since 2010 — an enormous tailwind for UnitedHealth, Humana, and Elevance.
Regulatory risk is ever-present: CMS (the Centers for Medicare and Medicaid Services) sets Medicare Advantage reimbursement rates annually. A significant cut to MA rates — as occurred in 2024’s CMS final rule — directly reduces insurer earnings and can trigger sector-wide selloffs.
Key Comparisons
- Johnson & Johnson vs Abbott: MedTech Rivalry
- Netflix vs Amazon Prime (see streaming sector)
Related Glossary Terms
- Gross Margin — varies enormously across healthcare sub-sectors
- Free Cash Flow — UnitedHealth and HCA are exceptional FCF generators
- EBITDA — hospital systems valued on EBITDA multiples
- Return on Invested Capital — the scorecard for capital deployment in healthcare M&A