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Healthcare IT

Why $4.9 trillion of American medicine still runs on 1966 software, and how AI finally reads the chart.

A $4.9 trillion industry runs on software designed in 1966, built for bedside safety and structurally unable to read its own data across patients. Healthcare didn't fail to digitize. It digitized brilliantly for the wrong question, and every downstream cost flows from that original choice.

Chapters
10
Reading time
28 min
Updated
18%of GDP is healthcarehighest of any rich nation
~$1Tspent on admin each yeara quarter of the total
44%of hospitals run Epicand ~70% of large systems (KLAS, 43.7% at end-2025)
Up to 50%of records fail to matchwhen shared across systems
$4.9TUS healthcare industryrunning on software designed in 1966

What this argues

  1. Digitized for the wrong question1966 architecture optimized for safety, not analytics.
  2. Washington paid for adoption, not connection$27B created digital silos.
  3. A duopoly hardened into a moatEpic and Oracle Health, guarded by data network effects.
  4. Interoperability is a compliance illusionThe semantic layer never got solved.
  5. AI attacks the real bottleneckMachines can finally read clinical language.
00

What has changed

Updated November 2026

43.7%Epic share of US acute-care hospitalsKLAS, end-2025, up from 42.3%
21.9%Oracle Health sharedown from 22.9% a year earlier
$7.4BUS digital-health funding, H1 2026Rock Health; $11.1B year to date through Q3
$112.7BUnitedHealth revenue, Q3 2026company release, 13 Oct 2026
May 2026

Epic widened its lead and Oracle Health kept losing hospitals

  • KLAS (reported by Fierce Healthcare and HIT Consultant, May 2026): Epic held 43.7% of US acute-care hospitals at the end of 2025, up from 42.3%, and 56.9% of beds.
  • Epic added 77 acute-care hospitals in 2025 while Oracle Health lost 56, its third consecutive year of the largest net share loss. Oracle Health fell to 21.9%.
  • Only two large health systems made enterprise-wide EHR decisions in 2025, and both chose Epic.
  • KLAS (via HIT Consultant, May 2026): 84% of Meditech customers deciding on a move chose to migrate to Expanse, up from 63% in 2024.
Q3 2026

Digital-health venture funding rebounded, and Rock Health stopped counting AI separately

  • Rock Health (H1 2026 report, via Fierce Healthcare and Healthcare Dive): US digital-health startups raised $7.4B across 244 deals in the first half, versus $6.4B across 245 deals in H1 2025.
  • Rock Health Q3 2026 update (via Milled summary): $3.7B across 114 deals in the quarter and $11.1B across 358 deals year to date, with the firm projecting the year to pass $14.8B.
  • Rock Health said it is retiring its separate AI-deal tracking because AI has become table stakes. A secondary source (ai2.work) cites its 2025 year-end report as putting AI companies at 54% of 2025 funding, up from 37% in 2024; this was not checked against the original.
February 2026

Medicare telehealth flexibilities extended through 2027

The flexibilities lapsed briefly on 31 January 2026 during a partial government shutdown. The Consolidated Appropriations Act, 2026, signed on 3 February 2026, extended them through 31 December 2027 (law-firm summaries from Foley, Greenbaum and AASM, early 2026). The reimbursement ceiling described in chapter 06 therefore moved out by two years but is still set by legislation.

April 2026

Ambient AI scribes drew large rounds

Abridge closed a $316M Series E extension in April 2026 at a $5.3B valuation, according to secondary coverage (valueaddvc and aggregator pages; not confirmed against a company release).

October 2026

UnitedHealth raised its 2026 outlook

UnitedHealth Group reported Q3 2026 revenue of $112.7B (versus $113.2B a year earlier), a medical care ratio of 88.4%, and raised full-year adjusted EPS guidance to at least $20.50 from $19.50-$20.00 (company 8-K and press coverage, 13 Oct 2026). UnitedHealthcare served 48.3M consumers and Optum over 120M patients and consumers in the release.

Breach count

Change Healthcare breach total unchanged at 192.7M

UnitedHealth's final count of 192.7M affected individuals (reported August 2025, via HHS site) is still the latest figure found.

Not refreshed: Meditech and Others hospital shares (Others is recomputed as the remainder), HL7/TEFCA status, prior-authorization survey figures, revenue-cycle market size, telehealth claim-line share for 2025-26, Teladoc, FDA AI clearances, ambient-AI health-system counts, UnitedHealth lives covered (52M, differing definition from the 48.3M in the Q3 release), and 2025 full-year Rock Health total.

Test yourself

Epic added 77 acute-care hospitals in 2025 while Oracle Health lost 56. What does this show?

The February 2026 law extended Medicare telehealth flexibilities through 2027. What does that imply?

01

Digitized by Decree

Why healthcare modernized late

A mother arrives unconscious. The ER can't see she is allergic to penicillin, because her records sit in another hospital's system. In US healthcare, one patient's history can be scattered across ten or more platforms that cannot talk to each other.

Why paper failed

The four failures that finally forced digitization

  • Safety. Illegible scripts and missing allergy data caused thousands of deaths a year.
  • Efficiency. Physicians re-ordered tests they couldn't locate: duplicate work, duplicate cost.
  • Coordination. The average patient saw seven doctors; none could see the others' notes.
  • Speed. An unconscious patient's history was simply unavailable in the ER.
The mandate worked

HITECH digitized nearly every hospital in six years

US hospital EHR adoption %
View the data
Hospitals with an EHR
20089
201128
201359
201584
201796

Source: ONC / American Hospital Association (2008-2017) · values read from the chart, approximate

$27 billionTaxpayer money that pushed hospital EHR adoption from 9% to 96%HITECH (2009) paid up to $44,000 per physician to adopt an EHR and rewarded adoption, not connection. Paper silos simply became digital silos, owned by a handful of vendors.

Test yourself

Why did HITECH's $27 billion leave records trapped in separate systems?

According to the chapter, what created the political will to spend billions on digitization?

02

The Architecture Trap

The 1966 decision that still rules

4 KBThe RAM budget that still shapes American medicineIn 1966, Mass General's EHR had to serve 20 departments on a PDP-7 with ~4 kilobytes of memory and never crash during care. The database design that solved it, MUMPS, is still the foundation of Epic and Meditech in 2026.
How MUMPS works

A superb answer to a 1966 question

  • Fused layers: OS, language and database welded into one, so you can't upgrade a piece; you replace the whole system.
  • Tree 'globals': data stored as branches that exist only when data does. Genius on 4KB, meaningless without the vendor's dictionary.
  • Built for concurrency: each department writes to its own branch at once, never colliding. Perfect for the bedside.
  • The tradeoff: fast for one patient, brutal across millions. A population query must walk every tree.
Two data models, two worlds

Why the same question is instant or impossible

Relational (SQL)Hierarchical (MUMPS)
Shapetables with fixed columnsper-patient trees, no columns
Find all diabetics >65one indexed query, millisecondswalk every patient's tree, one by one
Built forreading across populationsone patient, right now
Weaknessassumes memory the 1960s lackedpopulation analytics fights live care
Epic's workaround

How analytics got bolted onto a system that can't do it

  1. Chronicles: the live MUMPS database. Fast writes, tree-structured, unsafe to query at scale.
  2. Nightly ETL: a batch job copies everything after hours, a ~24-hour cycle.
  3. Clarity: a separate SQL warehouse. Relational, analytics-ready, safe to query.
  4. The 24-hour gap: reports run on yesterday's data; a deteriorating patient is flagged too late.
Why no one has escaped

The moat around 1966 architecture

  • Switching cost. $50-500M and 18-36 months, both systems running at once.
  • Clinical safety. A new system must prove it never crashes during care, which needs scale.
  • Chicken-and-egg. Reaching scale needs early adopters willing to bet patients' safety.
  • Network effects. The value of an EHR rises with how many peers share it.

Test yourself

A hospital wants a list of all diabetic patients over 65 from a MUMPS-style live database. What happens?

Why might a sepsis alert fire too late in an EHR analytics stack?

03

The EHR Duopoly

Two vendors, and a data moat

A duopoly drifting to monopoly

Two companies control most US hospital records

US hospital EHR market share %
View the data
Share of hospitals
Epic43.7
Oracle Health (Cerner)21.9
Meditech15
Others19.4

Source: KLAS Research (end-2025 data, published 2026); Meditech and Others not refreshed

Epic vs Oracle Health

The two firms that own the record of truth

EpicOracle Health (Cerner)
Ownershipprivate, founder-ledpublic; Oracle acquired for $28.3B (2022)
Hospital share~44%, leads 500+ bed systems~22% and slipping
ArchitectureMUMPS, built in-houseMUMPS, acquisition-stitched
Strategyone integrated record, organic growthcloud re-platform under Oracle
Momentum+77 hospitals in 2025 (+176 in 2024)-56 hospitals in 2025, third straight year of largest net loss
One system, one record

Why Epic sells an ecosystem, not a product

  1. The moat: one patient record no rival can assemble module by module.
  2. Analytics: Cogito, Caboodle and SlicerDicer, plus Cosmos across 250M+ patients.
  3. Patient and mobile: the MyChart portal; Haiku and Canto clinician apps.
  4. Operational modules: scheduling, registration, pharmacy, lab, radiology, OR, billing.
  5. Clinical core: EpicCare inpatient and ambulatory, one chart across every setting.
The EHR duopoly

The moat that compounds

  1. More hospitals adopt Epic.
  2. Care Everywhere grows more valuable.
  3. ~90% of residents train on Epic.
  4. Switching costs reach $50-500M.
  5. Churn falls toward zero.
  6. The loop repeats: data and network effects.
Two ways to beat interoperability

If data won't flow between firms, erase the boundary

Horizontal: EpicVertical: UnitedHealth
Moveown one layer completelyown many layers at once
Logicif everyone runs Epic, interop is internaldata flows freely inside one company
Reach~42% of hospitalsinsurer + 90K doctors + PBM + claims
Churn / EdgeChurn: ~zero in 47 yearsEdge: sees ~40% of all US claims
The vertical giant

UnitedHealth owns the whole pathway

$112.7BUnitedHealth Group revenue in Q3 2026 aloneinsurance + care + pharmacy + claims (UnitedHealth, 13 Oct 2026)
52Mlives coveredthe largest US insurer
90,000+physicians employedthrough Optum Health
~40%of US claims seenvia Change Healthcare

Test yourself

Why does leaving Epic cost on the order of $50-500M?

Epic gained 77 hospitals in 2025 and Oracle Health lost 56. By how many hospitals did the gap between them widen?

04

The Interoperability Illusion

Forty years, six standards

Six standards in forty years. Each solved a layer. None solved all four. Machines can now exchange the envelope of clinical data. They still can't read the letter inside.

The standards saga

Four decades of trying to make records talk

  1. HL7 v2: a shared message format, but ~20% stayed proprietary.
  2. HL7 v3: rigorous, unreadable, barely adopted.
  3. HITECH: $27B digitized the silos, not the connections.
  4. FHIR: web-style APIs cut interface cost from $500K to ~$50K.
  5. Cures Act: made data-blocking illegal, with fines up to $1M.
  6. TEFCA: one national hub instead of thousands of contracts.
Four layers, one gap

Interoperability is mostly solved, where it isn't matters most

  1. Foundational: the pipes connect (systems connect).
  2. Structural: the format is consistent.
  3. Organizational: governance and consent align.
  4. Semantic: meaning is shared. This is the gap (machines understand).
Usage is not utility

Hospitals can exchange data; clinicians rarely use it

Interoperability on paper versus in practice %
View the data
Share
Hospitals can exchange70
Clinicians who use the data42
Projects hitting ROI35
Key variables missing22

Source: ONC; KLAS; HIMSS (2023)

Why not just copy Estonia?

Consolidation is necessary but not sufficient

Estonia: centralizedUnited States: fragmented
Scale1.3M people340M people, 6,000+ hospitals, 50 state regimes
Structureone national health-IT backbone, a universal patient ID; near-total interoperability by 2008, before HITECH even beganno national patient ID, and a competitive vendor market with every reason to keep data in

Test yourself

About 70% of hospitals can exchange records, yet only 42% of clinicians use outside data. What is the best reading?

Which interoperability layer is still unsolved?

05

The Claims Machine

The $1 trillion administrative layer

A large share of American healthcare exists to translate care into a bill, and then to argue over it. Roughly $1 trillion a year, about a quarter of all health spending, pays for administration, not care. Per capita, the US spends ~3.5x what Canada does.

Complexity is a growth business

The revenue-cycle industry is set to nearly double

Revenue-cycle management market $B
View the data
Market size
2024142
2030 (est.)273

Source: Research and Markets (2024)

How a claim becomes payment

Every hop translates clinical reality into billing language

  1. Encounter: the clinician documents the visit in the EHR as free text.
  2. Coding: 185,000 coders translate notes into ICD-10 and CPT codes.
  3. Clearinghouse: Change Healthcare routes ~40% of all US claims.
  4. Adjudication: the payer approves, denies or downcodes, 14 to 30 days.
  5. Paid or denied: 10%+ are denied; 80%+ of appeals are later overturned.
Permission before treatment

Prior authorization is friction by design

93%of physicians report care delayscaused by prior authorization
13 hrsper physician per weekspent responding to requests
29%report a serious adverse eventtied to an authorization delay
81.7%of denials overturned on appealwhen providers push back
192.7 millionAmericans exposed in the 2024 Change Healthcare breachA single clearinghouse processing ~40% of US claims was ransomed via a portal with no multi-factor authentication. UnitedHealth paid $22M in Bitcoin; total impact topped $2.45B and 94% of hospitals reported damage. Concentration is efficient until it isn't.

Test yourself

About 81.7% of denials are overturned on appeal. What does the chapter suggest?

Revenue-cycle management is projected to grow from $142B (2024) to $273B (2030). Roughly what is the growth?

06

Telehealth's Reset

Boom, bust, and a durable floor

The spike that didn't fully retreat

Telehealth normalized at ~5x its old level

Telehealth, % of US medical claim lines %
View the data
Share of claim lines
20190.2
2020 peak13
20215.2
20225.4
20235.5
20245.1

Source: FAIR Health Monthly Telehealth Tracker; McKinsey · values read from the chart, approximate

The numbers behind the reset

What the pandemic permanently changed

38xpeak vs pre-COVID usethen settled far lower
13%of claim lines at the 2020 peaknow ~5-6%
>50%of telehealth is behavioral healthits stickiest use
$18.5BTeladoc-Livongo merger (2020)later written down ~$13B
What stuck and what didn't

The reset sorted telehealth into winners and losers

  • Behavioral health. The durable winner: most telehealth visits, no physical exam needed.
  • Chronic-care check-ins. Medication management and follow-ups moved online for good.
  • Primary and urgent care. Reverted largely to in-person once offices reopened.
  • The reimbursement cliff. Pandemic payment parity was temporary and has been extended in two-year steps; policy, not tech, sets the ceiling.

Telehealth's limit is no longer the technology. It is the reimbursement rule. The durable question is not whether a visit can happen over video, but whether it will be paid the same when it does.

Test yourself

According to the chapter, what mainly sets telehealth's ceiling today?

Why did behavioral health become telehealth's stickiest use?

07

AI Reads the Chart

The bottleneck finally lifts

For sixty years, software could exchange clinical data but never understand it. Language models changed that. Every constraint in this deck collapses into one bottleneck, machine comprehension of clinical language, that is finally being lifted.

1-2 hoursPhysician time per day spent typing notes, not treatingDocumentation burden is the clearest first target for AI: models that listen to the visit and draft the note live. Over 100 health systems now run ambient tools from Abridge, Nuance DAX and Ambience, the fastest-adopted clinical AI yet.
Where AI is landing first

Attacking the friction, not the fortress

  • Ambient documentation: AI listens and drafts the note live, 100+ systems (Abridge, DAX, Ambience).
  • Coding and prior auth: models read the record and generate payer-specific, code-accurate requests.
  • Trial matching: free-text records screened against trial criteria in minutes, not weeks.
  • The unlock: LLMs finally read clinical language. 'MI' = 'heart attack' = 'acute MI'.
  • The Olive lesson: an $850M startup died automating the UI, not the meaning. Semantics is the moat.
  • The pincer: enterprise compression inside the system, patient aggregation outside, at once.
Two vectors on the lock

Reform the institutions, or route around them

The institutional vectorThe patient vector
Pathforce vendors to share via standardspatients download their own records
ToolsHL7, FHIR, Cures Act, TEFCAHIPAA right of access + AI to read them
Speed40 years, slow, loophole-riddenbypasses vendor consent entirely
Ceilingcompliance, not utilityconsumer adoption and trust

Test yourself

What does the Olive example teach?

Why might the patient vector move more usable data than standards efforts?

08

The Investment Case

Where the capital is going

Froth gone, flight to AI

Digital-health funding fell ~65% from its 2021 peak

US digital-health venture funding $B
View the data
Funding
202014.7
202129.1
202215.3
202310.8
202410.1
H1 20267.4

Source: Rock Health (2020-2024; H1 2026 half-year total)

The opportunity map

AI's beachhead is the unlocked, high-friction work

A two-by-two map plots AI disruption potential (vertical) against incumbent lock-in (horizontal). Top-left is the open field for AI and bottom-right is the entrenched moats. Ambient documentation, prior authorization and patient data aggregation sit toward the open field. Revenue-cycle and coding sits top-right, as contested high ground. Clearinghouses and claims, medical imaging AI, and the EHR system of record sit toward the entrenched, high-lock-in side, with the EHR system of record lowest on disruption potential.

The landscape

Who owns what across the stack

  • The EHR fortresses: Epic (private), Oracle Health, Meditech, the systems of record.
  • The verticals: UnitedHealth/Optum, CVS/Aetna, insurance-to-pharmacy under one roof.
  • The admin layer: athenahealth, Waystar, Veradigm, RCM and claims plumbing.
  • Ambient AI: Abridge, Ambience, Nuance/Microsoft, Suki, the scribe wars.
  • Consumer rails: Apple Health, Hims, Doximity, GoodRx, the patient front door.
  • The platforms: OpenAI, Anthropic, Google, Amazon, betting the bottleneck is gone.
The capital picture

Where the dollars are moving now

$29.1B2021 funding peakthe froth year (Rock Health)
~$10B2024 fundingdown ~65% from peak
~40%of 2024 rounds are AI-firstthe flight to AI
$28.3BOracle's price for Cernerthe biggest bet on the record (2022)

Test yourself

Funding fell from $29.1B in 2021 to about $10B in 2024. Roughly what is the drop?

Where does the chapter say capital is going?

09

Reference

Glossary and sources

Reference

Plain-language glossary

TermMeaning
EHRelectronic health record, the digital chart and system of record.
HL7 / FHIRstandards for exchanging clinical data; FHIR is the modern API version.
Interoperabilitythe ability of different systems to share and actually use data.
Prior authorizationinsurer pre-approval required before certain treatments.
MUMPSthe 1966 language and database still underneath Epic and Meditech.
HITECH2009 law that paid $27B to digitize hospital records.
RCMrevenue-cycle management, turning care delivered into payment collected.
Ambient documentationAI that listens to a visit and drafts the clinical note.

Healthcare didn't refuse to modernize. It modernized perfectly, for a question the world stopped asking. The bill for that mismatch is a trillion dollars a year, and the receipt is a record no one can fully read.

Reference

Sources and further reading

  • CMS: National Health Expenditure data (2024).
  • KLAS Research: US acute-care EHR market share (2024-25).
  • ONC / HealthIT.gov: hospital EHR adoption and interoperability metrics.
  • McKinsey & Company; Annals of Internal Medicine: healthcare administrative cost.
  • American Medical Association: prior authorization physician survey (2023-24).
  • Rock Health: US digital health funding reports (2021-2024).
  • FAIR Health: Monthly Telehealth Regional Tracker.
  • Institute of Medicine: 'To Err Is Human' (1999); Pew Charitable Trusts / GAO: patient matching.
  • Figures marked 'estimate' are compilations of the above.

Test yourself

Which statement about MUMPS matches the glossary?

What does the glossary say interoperability means?

Sources cited

CMS · McKinsey · KLAS Research · Pew Charitable Trusts · GAO · Institute of Medicine · NCBI · ONC · American Hospital Association · Becker's Health IT · Epic · UnitedHealth Group filings · HL7 · HIMSS · European Commission · CDC · BLS · Experian · Research and Markets · American Medical Association · HHS OIG · FAIR Health · Rock Health · Annals of Internal Medicine · Company filings and disclosures · KLAS Research, May 2026 (via Fierce Healthcare, HIT Consultant) · Rock Health, H1 and Q3 2026 (via Fierce Healthcare, Healthcare Dive, Milled) · UnitedHealth Group Q3 2026 earnings release, Oct 2026 · Foley, Greenbaum Traurig and AASM summaries of the Consolidated Appropriations Act, 2026 (Feb 2026) · Abridge funding coverage, Apr 2026

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Research, not investment advice. Figures as of , from the sources cited.

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