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

                                  SCHEDULE 13G



                    Under the Securities Exchange Act of 1934

                               (Amendment No. 2 )*

                            Navigant Consulting, Inc.
--------------------------------------------------------------------------------
                                (Name of Issuer)

                                  Common Stock
--------------------------------------------------------------------------------
                         (Title of Class of Securities)


                                    63935N107
                           --------------------------
                                 (CUSIP Number)



                                December 31, 2002
             -------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)



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

                                [x] Rule 13d-1(b)
                                [ ] 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 in 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).


                               Page 1 of 10 Pages

CUSIP No. 63935N107                   13G                     Page 2 of 10 Pages

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

            Liberty Wanger Asset Management, L.P.  36-3820584

--------------------------------------------------------------------------------
  2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

            Not Applicable                                               (a) [ ]

                                                                         (b) [ ]

--------------------------------------------------------------------------------
  3     SEC USE ONLY

--------------------------------------------------------------------------------
  4     CITIZENSHIP OR PLACE OF ORGANIZATION

            Delaware

--------------------------------------------------------------------------------
                       5    SOLE VOTING POWER
     NUMBER OF
                                None
       SHARES
                       ---------------------------------------------------------
    BENEFICIALLY       6    SHARED VOTING POWER

      OWNED BY                  3,869,300

        EACH           ---------------------------------------------------------
                       7    SOLE DISPOSITIVE POWER
     REPORTING
                                None
    PERSON WITH        ---------------------------------------------------------
                       8    SHARED DISPOSITIVE POWER

                                3,869,300

--------------------------------------------------------------------------------
  9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

            3,869,300

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

           Not Applicable                                                    [ ]

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

           9.1 %

--------------------------------------------------------------------------------
  12   TYPE OF REPORTING PERSON*

           IA

--------------------------------------------------------------------------------

CUSIP No. 63935N107                   13G                     Page 3 of 10 Pages

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

            WAM Acquisition GP, Inc.

--------------------------------------------------------------------------------
  2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

            Not Applicable                                               (a) [ ]

                                                                         (b) [ ]

--------------------------------------------------------------------------------
  3     SEC USE ONLY

--------------------------------------------------------------------------------
  4     CITIZENSHIP OR PLACE OF ORGANIZATION

            Delaware

--------------------------------------------------------------------------------
                       5    SOLE VOTING POWER
     NUMBER OF
                                None
       SHARES
                       ---------------------------------------------------------
    BENEFICIALLY       6    SHARED VOTING POWER

      OWNED BY                  3,869,300

        EACH           ---------------------------------------------------------
                       7    SOLE DISPOSITIVE POWER
     REPORTING
                                None
    PERSON WITH        ---------------------------------------------------------
                       8    SHARED DISPOSITIVE POWER

                                3,869,300

--------------------------------------------------------------------------------
  9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

            3,869,300

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

           Not Applicable                                                    [ ]

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

           9.1 %

--------------------------------------------------------------------------------
  12   TYPE OF REPORTING PERSON*

           CO

--------------------------------------------------------------------------------

CUSIP No. 63935N107                   13G                     Page 4 of 10 Pages

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

            Liberty Acorn Trust

--------------------------------------------------------------------------------
  2     CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

            Not Applicable                                               (a) [ ]

                                                                         (b) [ ]

--------------------------------------------------------------------------------
  3     SEC USE ONLY

--------------------------------------------------------------------------------
  4     CITIZENSHIP OR PLACE OF ORGANIZATION

            Massachusetts

--------------------------------------------------------------------------------
                       5    SOLE VOTING POWER
     NUMBER OF
                                None
       SHARES
                       ---------------------------------------------------------
    BENEFICIALLY       6    SHARED VOTING POWER

      OWNED BY                  2,476,000

        EACH           ---------------------------------------------------------
                       7    SOLE DISPOSITIVE POWER
     REPORTING
                                None
    PERSON WITH        ---------------------------------------------------------
                       8    SHARED DISPOSITIVE POWER

                                2,476,000

--------------------------------------------------------------------------------
  9     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           2,476,000

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

           Not Applicable                                                    [ ]

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

           5.8 %

--------------------------------------------------------------------------------
  12   TYPE OF REPORTING PERSON*

           IV

--------------------------------------------------------------------------------


                        
Item 1(a)                  Name of Issuer:

                                    Navigant Consulting, Inc.


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

                                    615 North Wabash Ave.
                                    Chicago, IL 60611


Item 2(a)                  Name of Person Filing:

                                    Liberty Wanger Asset Management, L.P. ("WAM")
                                    WAM Acquisition GP, Inc. the general partner of WAM
                                       ("WAM GP")
                                    Liberty Acorn Trust ("Acorn")


Item 2(b)                  Address of Principal Business Office:

                                    WAM, WAM GP and Acorn are all located at:

                                    227 West Monroe Street, Suite 3000
                                    Chicago, Illinois  60606


Item 2(c)                  Citizenship:

                                    WAM is a Delaware limited partnership; WAM
                                    GP is a Delaware corporation; and Acorn is a
                                    Massachusetts business trust.

Item 2(d)                  Title of Class of Securities:

                                    Common Stock

Item 2(e)                  CUSIP Number:

                                    63935N107

Item 3                     Type of Person:

                                    (d)     Acorn is an Investment Company under
                                            section 8 of the Investment Company Act.

                                    (e)     WAM is an Investment Adviser registered
                                            under section 203 of the Investment Advisers
                                            Act of 1940; WAM GP is the General Partner
                                            of the Investment Adviser.



                               Page 5 of 10 Pages


Item 4  Ownership (at December 31, 2002):

                 (a)     Amount owned "beneficially" within the meaning of
                         rule 13d-3:

                         3,869,300

                 (b)     Percent of class:

                         9.1% (based on 42,700,000 shares outstanding as of
                         November 14, 2002).

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

                           (i)     sole power to vote or to direct the vote:
                                   none
                          (ii)     shared power to vote or to direct the vote:
                                   3,869,300
                         (iii)     sole power to dispose or to direct the
                                   disposition of: none
                          (iv)     shared power to dispose or to direct
                                   disposition of: 3,869,300


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:

                The shares reported herein have been acquired on behalf of
                discretionary clients of WAM, including Acorn. Persons other
                than WAM and WAM GP are entitled to receive all dividends from,
                and proceeds from the sale of, those shares. Acorn is the only
                such person known to be entitled to all dividends from, and all
                proceeds from the sale of, shares reported herein to the extent
                of more than 5% of the class.

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:

                 Not Applicable

Item 9  Notice of Dissolution of Group:

                 Not Applicable


                               Page 6 of 10 Pages


                        
Item 10                    Certification:

                                    By signing below I certify that, to the best
                           of my knowledge and belief, the securities referred
                           to above were acquired and are held in the ordinary
                           course of business and 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.



                               Page 7 of 10 Pages

                                    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.

Date:  February 4, 2003


                The undersigned corporation, on the date above written, agrees
                and consents to the joint filing on its behalf of this Schedule
                13G in connection with its beneficial ownership of the security
                reported herein.

                                WAM Acquisition GP, Inc.
                                    for itself and as general partner of
                                    LIBERTY WANGER ASSET MANAGEMENT, L.P.


                                By:  /s/ Bruce H. Lauer
                                     ------------------------------------------
                                           Bruce H. Lauer
                                           Senior Vice President and Secretary


                The undersigned corporation, on the date above written, agrees
                and consents to the joint filing on its behalf of this Schedule
                13G in connection with its beneficial ownership of the security
                reported herein.

                                LIBERTY ACORN TRUST



                                By:  /s/ Bruce H. Lauer
                                     ------------------------------------------
                                           Bruce H. Lauer
                                           Vice President, Treasurer and
                                             Secretary


                               Page 8 of 10 Pages

                                  Exhibit Index


               
Exhibit 1         Joint Filing Agreement dated as of February 4, 2003 by and
                  among Liberty Wanger Asset Management, L.P., WAM Acquisition
                  GP, Inc. and Liberty Acorn Trust



                               Page 9 of 10 Pages