<PAGE>

                        Health Industry Investments, LLC
                                   Suite 1111
                           2600 Virginia Avenue, N.W.
                            Washington, DC 20037-1904
                                  202-342-8700
                                Fax: 202-342-8734



                                                              May 18, 2000


Mr. Frank Martin
I-Trax.com, Inc.
One Logan Square
Suite 2615
Philadelphia, PA  19103

            Re: Engagement Agreement
                Health Industry Investments, LLC #1231-00
                -----------------------------------------

Dear Frank:

         This letter confirms the agreement between I-Trax.com, Inc. and its
successors and assigns ("I-Trax"), on the one hand, and Health Industry
Investments, LLC and its successors and assigns ("Health Investments"), on the
other hand, whereby Health Investments is engaged by I-Trax to introduce I-Trax
to prospective clients interested in purchasing services and/or products from
I-Trax. Such services and/or products shall include disease management and
medical information systems to be implemented at healthcare providers, insurance
companies, and other purchasers. An initial list of potential I-Trax clients
identified by Health Investments ("Targets") is set forth in Exhibit A to this
letter. Exhibit A may be amended from time to time by Health Investments,
subject to I-Trax's approval, which approval shall not be unreasonably withheld.

         As consideration for Health Investments' services hereunder, I-Trax
shall issue and sell to Health Investments, and Health Investments shall
purchase from I-Trax, 20,000 shares of Common Stock, par value $.001 per share
("Common Stock" and such sale, the "Share Sale"). The Share Sale shall occur at
such time as I-Trax shall complete a private placement of not less than 300,000
shares of Common Stock (the "Private Placement"), but in any event within ninety
(90) days of the date hereof, at a per share price equal to the lesser of (a)
$2.50 and (b) the purchase price payable in the Private Placement. The Share
Sale shall be made pursuant to a Subscription Agreement, which shall require
Health Investments to make certain representations and warranties, including
such representations and warranties as would permit the Share Sale to qualify as
a private placement exempt from the registration requirements of the Securities
Act of 1933, as amended, and the applicable rules and regulations promulgated
thereunder. Furthermore, I-Trax shall grant to Health Investments for its
services under this Agreement non-qualified stock options (the "Options") to


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Mr. Frank Martin
May 18, 2000
Page 2

purchase an aggregate of up to 80,000 shares of Common Stock. The Options shall
vest over a period of twelve consecutive months, on the 16th day of each such
month, beginning on June 16, 2000 (such period, the "Period"). Options to
acquire 6,666 shares of Common Stock shall vest on the 16th day of each of the
initial eleven months of the Period and Options to acquire 6,674 shares of
Common Stock shall vest on the 16th day the last month of the Period. The grant,
exercise and termination of the Options shall be subject to the provisions of a
Non-Qualified Stock Option Grant Agreement in the form attached hereto as
Exhibit A. In addition to the Options grant, Health Investments shall bill
I-Trax separately, on a monthly basis, for expenses (e.g. copying charges,
telephone charges, travel charges, etc.) and payment shall be due within thirty
(30) days of I-Trax's receipt of an invoice in accordance with Health
Investments' standard billing policies.

         I-Trax shall provide Health Investments all information reasonably
requested by Health Investments related to the progress and status of I-Trax's
work for each Target. I-Trax shall indemnify and hold harmless Health
Investments, its directors, officers, employees and agents from any expenses
(including reasonable attorneys' fees) in connection with any claim arising from
services performed by I-Trax or products sold or licensed by I-Trax for a Target
or from contacts between I-Trax and a Target.

         For a period of one year from the date hereof, this engagement may be
terminated by Health Investments without cause at any time and by I-Trax only
with "cause," as defined below. After such one year period, either party may
terminate this engagement without cause at any time. For purposes hereof,
"cause" shall mean Health Investments' act or failure to act that breaches its
obligations to I-Trax in the good faith judgment of the Board of Directors of
I-Trax.

         Health Investments acknowledges that certain non-public, confidential,
proprietary information of I-Trax (the "Confidential Information") may be
furnished to Health Investments. Health Investments agrees not to disclose any
Confidential Information to any person who is not a partner, officer, or
employee of Health Investments or a Health Investments affiliate or counsel to
Health Investments, except with the prior consent of I-Trax or pursuant to a
subpoena or order issued by a court of competent jurisdiction or by a judicial,
administrative, or legislative body or committee; provided, however, that prior
to making any disclosure of Confidential Information pursuant to any such
subpoena or order, Health Investments will provide I-Trax with immediate prior
notice to enable I-Trax to seek appropriate protective order. Information will
not be deemed Confidential Information that: (1) is already in the possession of
Health Investments; (2) becomes available in the public domain other than as a
result of unauthorized disclosure by Health Investments, or its shareholders,
officers, members, partners, employees or advisors; or (3) is not acquired from
I-Trax or persons known by Health Investments to be in breach of an obligation
of secrecy to I-Trax.


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Mr. Frank Martin
May 18, 2000
Page 3


         Health Investments further acknowledges that it is aware that United
States securities laws prohibit any person which has received from an issuer
material, non-public information from purchasing or selling securities of such
issuer or from communicating such information to any other person under
circumstances in which it is reasonably foreseeable that such person is likely
to purchase or sell such securities.

         This Letter Agreement may not be assigned by either party hereto
without the other party's written consent; provided, however, Health Investments
may assign this agreement to Akin Gump Health Strategies, LLC ("Strategies")
without such written consent if (a) Philip D. Green holds a position of
management in Strategies and (b) I-Trax is delivered written notice of such
assignment ten (10) days in advance of such assignment. The terms of this Letter
Agreement shall be governed and construed under the laws of the District of
Columbia, notwithstanding any conflict of laws or choice of law provisions to
the contrary. Venue for any action to enforce the terms of this Letter Agreement
shall be in the District of Columbia.

         Please confirm that the foregoing is in accordance with I-Trax's
understanding by signing and returning to Health Investments a copy of this
letter, which shall become a binding agreement upon our receipt. We are pleased
to assist I-Trax, and look forward to working with you and your colleagues.

                                                Sincerely,

                                                HEALTH INDUSTRY INVESTMENTS, LLC



                                                   By: /s/ Philip D. Green
                                                       ------------------------
                                                   Name: Philip D. Green
                                                   Title:

ACCEPTED AND AGREED:

I-TRAX.COM, INC.

By:  Frank A. Martin
   -------------------------------
     Frank Martin, Chairman

Date:
       -------------------------------------