FORM 3
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
  Gilbreth Mark
2. Date of Event Requiring Statement (Month/Day/Year)
04/21/2006
3. Issuer Name and Ticker or Trading Symbol
CAPSTONE TURBINE CORP [cpst]
(Last)
(First)
(Middle)
21211 NORDHOFF STREET
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
EVP & Chief Operating Officer
5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

CHATSWORTH, CA 91311
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security
(Instr. 4)
2. Amount of Securities Beneficially Owned
(Instr. 4)
3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)
4. Nature of Indirect Beneficial Ownership
(Instr. 5)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)
2. Date Exercisable and Expiration Date
(Month/Day/Year)
3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)
4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)
6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Employee Stock Option (right to buy) 12/01/1998(1) 12/01/2007 Common Stock 437 $ 1 D  
Employee Stock Option (Right to buy) 11/01/1999(2) 11/01/2008 Common Stock 4,500 $ 2.5 D  
Employee Stock Option (Right to buy) 05/01/2000(3) 05/01/2009 Common Stock 12,750 $ 0.33 D  
Employee Stock Option (Right to Buy) 02/18/2001(4) 02/18/2010 Common Stock 13,000 $ 3.33 D  
Employee Stock Option (Right to buy) 06/26/2003(5) 06/26/2012 Common Stock 12,000 $ 1.89 D  
Employee Stock Option (Right to Buy) 01/26/2005(6) 01/26/2014 Common Stock 75,000 $ 2.36 D  
Employee Stock Option (Right to buy) 09/09/2005(7) 09/09/2014 Common Stock 25,000 $ 1.58 D  
Employee Stock Option (Right to Buy) 03/17/2006(8) 03/17/2005 Common Stock 110,000 $ 1.64 D  
Employee Stock Option (Right to Buy) 10/31/2006(9) 10/31/2015 Common Stock 100,000 $ 2.43 D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Gilbreth Mark
21211 NORDHOFF STREET
CHATSWORTH, CA 91311
      EVP & Chief Operating Officer  

Signatures

Mark Gilbreth 05/01/2006
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) This grant was originally for 3,000 shares which became exercisable as to 25% on December 1, 1998 and thereafter vests monthly for 36 months.
(2) This grant was originally for 12,000 shares which became exercisable as to 25% on November 1, 1999 and thereafter vests monthly for 36 months.
(3) This grant was originally for 36,000 shares which became exerciable as to 25% on May 1, 2000 and thereafter vests monthly for 36 months.
(4) This grant was originally for 18,000 shares which became exercisable as to 25% on Feburary 18, 2001 and thereafter vests monthly for 36 months.
(5) This grant became exercisable as to 25% on June 26, 2003 and thereafter vests monthly for 36 months.
(6) This grant became exercisable as to 25% on January 26, 2005 and thereafter vests monthly for 36 months.
(7) This grant became exercisable as to 25% on September 9, 2005 and thereafter vests monthly for 36 months.
(8) This grant became exercisable as to 25% on March 17, 2006 and thereafter vests monthly for 36 months.
(9) This grant becomes exercisable as to 25% on October 31, 2006 and thereafter vests monthly for 36 months.

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