UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549



                                  SCHEDULE 13G

                   Under the Securities Exchange Act of 1934*


                                  I-trax, Inc.
                                  ------------
                                (Name of Issuer)

                         Common Stock, $0.001 par value
                         ------------------------------
                         (Title of Class of Securities)

                                    45069D203
                                    ---------
                                 (CUSIP Number)

                                 March 19, 2004
                                 --------------
             (Date of Event Which Requires Filing of this Statement)

                   Check the appropriate box to designate the
                 rule pursuant to which this Schedule is filed:

                                [ ] Rule 13d-1(b)
                                [X] Rule 13d-1(c)
                                [ ] Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).




-------------------                                            -----------------
CUSIP No. 45069D203                   13G                      Page 2 of 8 Pages
-------------------                                            -----------------

--------------------------------------------------------------------------------
1      NAME OF REPORTING PERSON
       S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

       Warburg, Pincus Ventures, L.P. - (IRS Identification No. 13-3784037)
--------------------------------------------------------------------------------
2      CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) [ ]

                                                                         (b) [X]

--------------------------------------------------------------------------------
3      SEC USE ONLY
--------------------------------------------------------------------------------
4      CITIZENSHIP OR PLACE OF ORGANIZATION

       Delaware
--------------------------------------------------------------------------------
              5    SOLE VOTING POWER

                   4,772,056 shares, except that Warburg Pincus & Co. ("WPC"),
                   the sole general partner of Warburg, Pincus Ventures, L.P.
                   ("WPV"), may be deemed to have shared voting power with
                   respect to such shares and Warburg Pincus LLC ("WPLLC"), the
                   manager of WPV, may be deemed to have shared voting power
                   with respect to such shares.
              ------------------------------------------------------------------
  NUMBER OF   6    SHARED VOTING POWER
   SHARES
BENEFICIALLY       See response to row 5.
  OWNED BY
    EACH      ------------------------------------------------------------------
  REPORTING   7    SOLE DISPOSITIVE POWER
   PERSON
    WITH           4,772,056 shares, except that WPC, the sole general partner
                   of WPV, may be deemed to have shared dispositive power with
                   respect to such shares and WPLLC, the manager of WPV, may be
                   deemed to have shared dispositive power with respect to such
                   shares.
              ------------------------------------------------------------------
              8    SHARED DISPOSITIVE POWER

                   See response to row 7.
--------------------------------------------------------------------------------
9      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

       4,772,056
--------------------------------------------------------------------------------
10     CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

       [ ]
--------------------------------------------------------------------------------
11     PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

       16.5%
--------------------------------------------------------------------------------
12     TYPE OF REPORTING PERSON*

       PN
--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!




-------------------                                            -----------------
CUSIP No. 45069D203                   13G                      Page 3 of 8 Pages
-------------------                                            -----------------

--------------------------------------------------------------------------------
1      NAME OF REPORTING PERSON
       S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

       Warburg Pincus & Co. - (IRS Identification No. 13-6358475)
--------------------------------------------------------------------------------
2      CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) [ ]

                                                                         (b) [X]

--------------------------------------------------------------------------------
3      SEC USE ONLY
--------------------------------------------------------------------------------
4      CITIZENSHIP OR PLACE OF ORGANIZATION

       New York
--------------------------------------------------------------------------------
              5    SOLE VOTING POWER

                   4,772,056 shares, all of which are beneficially owned by WPV.
                   WPC is the sole general partner of WPV and WPLLC is the
                   manager of WPV. WPC and WPLLC may be deemed to share with WPV
                   voting power with respect to such shares.
              ------------------------------------------------------------------
  NUMBER OF   6    SHARED VOTING POWER
   SHARES
BENEFICIALLY       See response to row 5.
  OWNED BY
    EACH      ------------------------------------------------------------------
  REPORTING   7    SOLE DISPOSITIVE POWER
   PERSON
    WITH           4,772,056 shares, all of which are beneficially owned by WPV.
                   WPC is the sole general partner of WPV and WPLLC is the
                   manager of WPV. WPC and WPLLC may be deemed to share with WPV
                   dispositive power with respect to such shares.
              ------------------------------------------------------------------
              8    SHARED DISPOSITIVE POWER

                   See response to row 7.
--------------------------------------------------------------------------------
9      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

       4,772,056
--------------------------------------------------------------------------------
10     CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

       [ ]
--------------------------------------------------------------------------------
11     PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

       16.5%
--------------------------------------------------------------------------------
12     TYPE OF REPORTING PERSON*

       PN
--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!




-------------------                                            -----------------
CUSIP No. 45069D203                   13G                      Page 4 of 8 Pages
-------------------                                            -----------------

--------------------------------------------------------------------------------
1      NAME OF REPORTING PERSON
       S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

       Warburg Pincus LLC - (IRS Identification No. 13-3536050)
--------------------------------------------------------------------------------
2      CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                         (a) [ ]

                                                                         (b) [X]

--------------------------------------------------------------------------------
3      SEC USE ONLY
--------------------------------------------------------------------------------
4      CITIZENSHIP OR PLACE OF ORGANIZATION

       New York
--------------------------------------------------------------------------------
              5    SOLE VOTING POWER

                   4,772,056 shares, all of which are beneficially owned by WPV.
                   WPLLC is the manager of WPV and WPC is the sole general
                   partner of WPV. WPC and WPLLC may be deemed to share with WPV
                   voting power with respect to such shares.

              ------------------------------------------------------------------
  NUMBER OF   6    SHARED VOTING POWER
   SHARES
BENEFICIALLY       See response to row 5.
  OWNED BY
    EACH      ------------------------------------------------------------------
  REPORTING   7    SOLE DISPOSITIVE POWER
   PERSON
    WITH           4,772,056 shares, all of which are beneficially owned by WPV.
                   WPLLC is the manager of WPV and WPC is the sole general
                   partner of WPV. WPC and WPLLC may be deemed to share with WPV
                   dispositive power with respect to such shares.
              ------------------------------------------------------------------
              8    SHARED DISPOSITIVE POWER

                   See response to row 7.
--------------------------------------------------------------------------------
9      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

       4,772,056
--------------------------------------------------------------------------------
10     CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

       [ ]
--------------------------------------------------------------------------------
11     PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

       16.5%
--------------------------------------------------------------------------------
12     TYPE OF REPORTING PERSON*

       OO
--------------------------------------------------------------------------------
                      *SEE INSTRUCTION BEFORE FILLING OUT!




This Schedule 13G is being filed with respect to the Common Stock, $0.001 par
value of I-trax, Inc.

Item 1(a):          Name of Issuer:
----------          ---------------

     I-trax, Inc., a Delaware corporation (the "Company").

Item 1(b):          Address of Issuer's Principal Executive Offices:
----------          ------------------------------------------------

     One Logan Square, Suite 2615
     130 N. 18th Street
     Philadelphia, Pennsylvania 19103

Item 2(a):          Name of Person Filing:
----------          ----------------------

     Warburg, Pincus Ventures, L.P. ("WPV")

     Warburg Pincus & Co. ("WPC")

     Warburg Pincus LLC ("WPLLC")

Item 2(b):          Address of Principal Business Office or, if None, Residence:
----------          ------------------------------------------------------------

     466 Lexington Avenue
     New York, New York 10017

Item 2(c):          Citizenship:
----------          ------------

     WPV is a Delaware limited partnership

     WPC is a New York general partnership

     WPLLC is a New York limited liability company

Item 2(d):          Title of Class of Securities:
----------          -----------------------------

     Common Stock, $0.001 par value (the "Common Stock")

Item 2(e):          CUSIP Number:
----------          -------------

     45069D203

Item 3:             If this statement is filed pursuant to Rules 13d-1(b) or
-------             --------------------------------------------------------
                    13d-2(b) or (c), check whether the person filing is a:
                    ------------------------------------------------------

     Not applicable.

Item 4:             Ownership:
-------             ----------

     As to each of WPV, WPC and WPLLC (individually, a "Reporting Person" and
collectively the "Reporting Persons"):


                                      -5-




     (a)  Amount beneficially owned: 4,772,056

     (b)  Percent of class: 16.5%

     (c)  Number of shares as to which the person has:

          (i) Sole power to vote or direct the vote: See Row 5 for each
          Reporting Person.

          (ii) Shared power to vote or direct the vote: See Row 6 for each
          Reporting Person.

          (iii) Sole power to dispose or direct the disposition of: See Row 7
          for each Reporting Person.

          (iv) Shared power to dispose or direct the disposition of: See Row 8
          for each Reporting Person.

Item 5:             Ownership of Five Percent or Less of a Class:
-------             ---------------------------------------------

     Not applicable.

Item 6:             Ownership of More than Five Percent on Behalf of Another
-------             --------------------------------------------------------
                    Person:
                    -------

     Not applicable.

Item 7:             Identification and Classification of the Subsidiary Which
-------             ---------------------------------------------------------
                    Acquired the Security Being Reported on by the Parent
                    -----------------------------------------------------
                    Holding Company:
                    ----------------

     Not applicable.

Item 8:             Identification and Classification of Members of the Group:
-------             ----------------------------------------------------------

     The Reporting Persons are making this single, joint filing because they may
be deemed to constitute a "group" within the meaning of Section 13(d)(3) of the
Securities Exchange Act of 1934, as amended (the "Exchange Act"). The agreement
among the Reporting Persons to file jointly is attached hereto as Exhibit 1.
Each Reporting Person disclaims beneficial ownership of the Common Stock except
to the extent of its pecuniary interest therein.

Item 9:             Notice of Dissolution of Group:
-------             -------------------------------

      Not applicable.

Item 10:            Certification:
--------            --------------

     Each Reporting Person hereby makes the following certification:

     By signing below I certify that, to the best of my knowledge and belief,
the securities referred to above were not acquired and are not held for the
purpose of or with the effect of changing or influencing the control of the
issuer of the securities and were not acquired and are not held in connection
with or as a participant in any transaction having that purpose or effect.


                                      -6-




                                    SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.


Dated: March 26, 2004

                                        WARBURG, PINCUS VENTURES, L.P.

                                        By: Warburg Pincus & Co.
                                            its General Partner

                                        By: /s/ Scott A. Arenare
                                            ------------------------------
                                          Name:  Scott A. Arenare
                                          Title: Partner


                                        WARBURG PINCUS & CO.

                                        By: /s/ Scott A. Arenare
                                            ------------------------------
                                          Name:  Scott A. Arenare
                                          Title: Partner


                                        WARBURG PINCUS LLC

                                        By: /s/ Scott A. Arenare
                                            ------------------------------
                                          Name:  Scott A. Arenare
                                          Title: Managing Director




                                  Exhibit Index

         Exhibit 1    Joint Filing Agreement, dated as of March 26, 2004