1. Goldman Sachs 26th Annual Global Healthcare Conference
June 16, 2005

2. Forward-Looking Statements
Statements included in this presentation or in the oral comments made as part of this presentation may contain forward-looking statements, including but not limited to statements of the Company’s plans, objectives, expectations or intentions, that involve risk and uncertainties.
The Company’s actual results may differ significantly from those projected or suggested in any forward-looking statement due to a variety of factors, which are discussed in detail in the Company’s filings with the Securities and Exchange Commission.

3. Our Interests are Aligned with Clients and Patients:
To make the use of prescription drugs safer and more affordable

4. Alignment –Formulary Management
Therapy Class
More Number of Drugs Fewer
We Provide Flexible Management of
the Supply Chain
1. Select number of drugs in therapy class
# of
drugs
# of
drugs
# of
drugs
# of
drugs

5. Alignment –Formulary Management
Therapy Class
More Number of Drugs Fewer
We Provide Flexible Management of
the Supply Chain
1. Select number of drugs in therapy class
2. Determine formulary control
Benefit Options
# of
drugs
# of
drugs
# of
drugs
# of
drugs
Open
Differential
Co-pay
Closed

6. Alignment –Formulary Management
Therapy Class
More Number of Drugs Fewer
We Provide Flexible Management of
the Supply Chain
1. Select number of drugs in therapy class
2. Determine formulary control
3. Drive towards lowest overall cost
Benefit Options
# of
drugs
# of
drugs
# of
drugs
# of
drugs
Open
Differential
Co-pay
Impact on Client
Impact on Patient
Impact on ESI
Lower drug cost
More choice
Lower co payment
Higher Profit/Rx
More Flexibility
Lowest
Overall
Cost
Closed

7. Alignment - Retail Network Management
Greater Management
States
Available Pharmacies
Most Inclusive Network
Most Restrictive Network
TRICARE Access Minimum CA
5,644
5,071
3,881
283 NY
4,444
4,224
1,829
300 TX
4,236
3,821
1,827
579 FL
4,020
3,670
1,966
469 PA
2,970
2,825
1,687
432
Higher Profit/Rx
More Flexibility
Lower co payment
More choice
Lower drug cost
Impact on ESI
Impact on Patient
Impact on Client

8. Alignment – Clinical Programs
Plan Designs Encourage Greater Use of
Generics and Preferred Low-cost Brands
Impact on Client
Impact on Patient
Impact on ESI
Lower drug cost
Lower co payment
Higher Profit/Rx
Clients using step therapy realize on average a
2 percentage point increase in generic utilization

9. Alignment – Home Delivery
We Offer Highly Efficient, Cost-effective
Home Delivery
Impact on Client
Impact on Patient
Impact on ESI
Lower drug cost
Choice
Lower co payment
Higher profit/Rx

10. Alignment – Growing Demand for Mail
Increased home delivery penetration
* Represents network claims plus 3 times home delivery claims –home delivery claims are 90 days vs. 30 days in the network.
Excludes UHC claims
Home Delivery Helps Manage the Cost of Maintenance Drugs

11. Alignment – Generic Utilization
Express Scripts Leads in Generic Utilization
Impact on Client
Impact on Patient
Impact on ESI
Lowest drug cost
Lowest co payment
Highest profit/Rx
Source: From public filings

12. Alignment – Growing Generic Opportunity
Represents
over 20%
of 2004
branded
drug sales
ESI Analysis
Our Clients and Members Will Benefit From a Growing Generic Opportunity

13. Alignment – Specialty Pharmacy
Billions
100%
$35
Total
19%
3.5
Other 1%
0.5
Growth Hormone
Infertility 2%
0.6
RSV prophylaxis 4%
1.5
Rheumatoid arthritis
Multiple sclerosis
Transplant 5%
1.6
Hepatitis C
Hemophilia 9%
3.2
Renal
10%
3.4
HIV/AIDS
36%
$12.6
Oncology
Specialty Market
2004
Source: ESI Analysis
Impact on Client
Impact on Patient
Impact on ESI
Lower drug cost
Lower co payment
Higher profit/Rx
Improved reporting
Improved quality of care
Higher client satisfaction
Clients are Seeking Solutions for High-cost Specialty Drugs

14. CuraScript Penetration into Express Scripts
100 90 80 70 60 50 40 30 20 10
82%
73%
70%
69%
66%
Retail
Percentage of Plan Costs
CuraScript
25%
20%
17%
Mail
16%
14% 9% 2%
13%
13%
11%
Q1 2004
Q2 2004
Q3 2004
Q4 2004
Q1 2005
CuraScript Continues to Capture an Increased
Share of Our Client’s Specialty Spend

15. What Are the Savings? C O S T
Retail, Clinical.
Formulary
And Rebate
Savings 24%
Paid by
Cash Customer
at Pharmacy
Retail Pharmacy Cash Price
Mail Savings 6%
Express Scripts Client Savings
Express Scripts Client Costs C O S T
Paid by
Express Scripts
Clients
Total Savings 30%
Availability of Proven PBM Cost Management Tools
Will Produce 20%–25% Savings (CBO)

16. Alignment – A Win-Win-Win Proposition
Retail Non-pref. Brand
Retail Pref. Brand
Generics
Mail Pharmacy
Increased Savings
Opportunities:
Client
Member
Increased
Profit
Express Scripts
Moving to preferred brands, mail and generics
Moving to preferred brands, mail and generics
Moving to preferred brands, mail and generics
We make money by saving clients and members money

17. PBM’s Are Part of the Solution for Medicare
Average Annual Drug Spend
Among Medicare Population
Source: Actuarial Research Corporation
ESI is well positioned for 2006
Our 2006 offensive strategy is to help our managed care and carrier clients profitably grow their MA-PDs and PDPs
We are building the foundation for 2007
The Medicare Prescription Drug Act will shape
the direction of our industry for years to come

18. Benefits of ePrescribing
Prescription & Pharmacy Benefit Information
Point of
Sale
Point of Care
Benefit / Gain
Clinical
Messages at pharmacy
Physicians see clinical issues
Better informed, safer prescribing
Formulary
Enforcement after prescribing
Awareness at prescribing
Better choices, increased generics
Benefit
Referenced at pharmacy
Real-time guidance
Cost-effectiveness, fewer callbacks
Medication History
Partially known
History while prescribing
Patient safety
Prescription
Carried, faxed, called, mailed
Convenience at pharmacy
More efficient, patient safety
Medicare Part D Will Advance Important Initiatives Including e- Prescribing

19. We Deliver Against Client and Patient Expectations:
To make the use of prescription drugs safer and more affordable

20. Client/Patient Focus Why Express Scripts? Alignment With Clients
Generics
Specialty
By membership
Health Plan Sponsors Recognize Express Scripts Single
Focus on Making Prescription Drugs More Affordable

21. 2006 Upsell Pipeline is Strong
10,000
Significant potential to continue to manage client trends in key product categories
New products continue
to be developed and
rolled out
Strong track record of success
Sold
Weighted Pipeline
9,000
8,000
7,000
6,000
('000 Lives)
5,000
4,000
3,000
2,000
1,000
Home Delivery
Three Tier
Generic Enforcement
Narrowing Formularies
New Clinical Products
Specialty/CuraScript

22. Client Satisfaction Steadily Improving
Service and satisfaction metrics have increased consistently quarter over quarter since 2003 with an early spike in 2005
100%
95%
2003
90%
85%
2004
80%
1q05
75%
70%
65%
60%
ESI Performance
Exceed
Likelihood to
Likelihood to
Expectations
Recommend
Renew

23. Express Scripts has demonstrated a proven track record
Our Financial Results
Express Scripts has demonstrated a proven track record

24. Financial Overview Q1 2005 Highlights
1Q EPS $1.14 — up 28% from last year
Cash flow from operations of $ million versus $97.8 million last year
Record adjusted claims of 142 million, up 16% from last year
Record generic utilization of 54% versus 49% last year
Gross profit per adjusted claim of $1.87 versus $1.77 last year (excluding non-recurring gain last year)
Increased 2005 EPS guidance

25. Financial Overview Quality of Earnings (1) (3) (2)
Reflects a $70-$75 million reduction in Q due to one-time impact of implementing a new wholesale purchase agreement
Excludes a $0.10 per share charge for the early retirement of debt
Excludes a $0.20 charge to increase legal reserves for the cost of defense.
* Reflects a 12-month moving average of free cash flow (cash from operations less CapX)

26. Components of EPS Growth — 20046% 7% 8%
* Excluding $25 million charge to increase legal reserves for the cost of defense and $5.5 million termination payment received

27. EBITDA* per adjusted claim
Financial Overview
EBITDA* per adjusted claim
10.5% CAGR
Pricing can be lowered as clients tighten formulary compliance, increase home delivery, utilize generics and restrict retail networks. These changes result in lower prices to our clients and greater profits to Express Scripts.
* A reconciliation of EBITDA to net income and to net cash provided by operating activities can be found in the Investor Relations
section of Express Scripts’ Web site, under Presentations.
** Excluding $25 million charge to increase legal reserves for the cost of defense and $5.5 million termination payment received.

28. Gross Profit/SGA/EBITDA per Adj. Rx
Future EBITDA per Adj. Rx Must Come From Gross Profit per Adj. Rx
* Excluding $25 million charge to increase legal reserves for the cost of
defense and $5.5 million termination payment received.

29. Focus on Return on Invested Capital (ROIC)
* Reflects operating income less tax divided by average invested capital, which consists of stockholder’s equity, plus interest
bearing liabilities plus long-term deferred income taxes, net.
** Excludes $25 million charge to increase legal reserves for the cost of defense and 5.5 million termination payment received
ROIC is our Preferred Performance Metric

30. Why Express Scripts? Industry-Leading ROIC
We Lead Our Peer Group in ROIC Performance
Source: Express Scripts Analysis

31. Our Financial Goals 15% + EBITDA growth
Increase gross profit per claim
Maintain ROIC leadership
5%-7%
14%-16%

32. Our Value Proposition Will Continue to Drive Growth
Making the use of drugs safer and more affordable is more
important than ever
Plan sponsors will increasingly deploy our tools
Express Scripts is well-positioned for sustainable growth
Strong market fundamentals/new business opportunities
Increased use of home delivery and generic drugs
Growth in management of specialty pharmacy
Productivity and capital structure improvements
We have taken a different approach
Alignment -- we make money by saving our clients money
Strategic acquisitions have enhanced our value proposition