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

SCHEDULE 13G

Under the Securities Exchange Act of 1934

(Amendment No.            )*
-----------
ICU Medical, Inc.
(Name of Issuer)

Common Stock
(Title of Class of Securities)

44930G107
(CUSIP Number)

December 31, 2003
(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 9 pages

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CUSIP No. 44930G107                    13G                    Page 2 of 9 Pages
-------------------                                           ------------------

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

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

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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

--------------------------------------------------------------------------------
NUMBER OF      5    SOLE VOTING POWER

None
SHARES
------------------------------------------------------------
BENEFICIALLY   6    SHARED VOTING POWER

901,500
OWNED BY
------------------------------------------------------------
EACH           7    SOLE DISPOSITIVE POWER

None
REPORTING
------------------------------------------------------------
PERSON WITH    8    SHARED DISPOSITIVE POWER

901,500

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

901,500

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

6.6 %

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

IA

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-------------------                                           ------------------
CUSIP No. 44930G107                   13G                     Page 3 of 9 Pages
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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

--------------------------------------------------------------------------------
NUMBER OF          5    SOLE VOTING POWER

None
SHARES
------------------------------------------------------------
BENEFICIALLY       6    SHARED VOTING POWER

901,500
OWNED BY
------------------------------------------------------------
EACH               7    SOLE DISPOSITIVE POWER

None
REPORTING
------------------------------------------------------------
PERSON WITH        8    SHARED DISPOSITIVE POWER

901,500

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

901,500

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

6.6%

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

CO

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

Item 1(a) Name of Issuer:

ICU Medical, Inc.

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

951 Calle Amanecer
San Clemente, California 92673

Item 2(a) Name of Person Filing:

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

Item 2(b) Address of Principal Business Office:

WAM and WAM GP are both located at:

227 West Monroe Street, Suite 3000
Chicago, Illinois 60606

Item 2(c) Citizenship:

WAM is a Delaware limited partnership and WAM GP is a
Delaware corporation.

Item 2(d) Title of Class of Securities:

Common Stock

Item 2(e) CUSIP Number:

44930G107

Item 3    Type of Person:

(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 4 of 9 pages

Item 4   Ownership (at December 31, 2003):

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

901,500

(b)  Percent of class:

6.6 % (based on 13,650,003 shares outstanding as of October 31,
2003)

(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: 901,500

(iii) sole power to dispose or to direct the disposition of: none

(iv)  shared power to dispose or to direct disposition of: 901,500

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. Persons other than WAM and WAM GP are
entitled to receive all dividends from, and proceeds from the sale of,
those shares.

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 5 of 9 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 6 of 9 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 13, 2004

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
COLUMBIA WANGER ASSET
MANAGEMENT, L.P.

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

Page 7 of 9 pages

Exhibit Index

Exhibit 1 Joint Filing Agreement dated as of February 13, 2004 by and among
Columbia Wanger Asset Management, L.P. and WAM Acquisition GP, Inc.

Page 8 of 9 pages

EXHIBIT 1

JOINT FILING AGREEMENT

The  undersigned  hereby  agree to the joint  filing of the Schedule 13G to
which this Agreement is attached.

Dated: February 13, 2004

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

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

Page 9 of 9 pages