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


SCHEDULE 13G

Under the Securities Exchange Act of 1934


Amendment No.:      *


Name of Issuer: Blackboard Inc.


Title of Class of Securities: Common Stock


CUSIP Number: 091935502


Date of Event Which Requires Filing of this Statement: 2/28/2010


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).


CUSIP No.: 091935502

1.  NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
    Janus Capital Management LLC
    EIN #75-3019302

2.  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
    a.   ___
    b.   ___

3.  SEC USE ONLY

4.  CITIZENSHIP OR PLACE OF ORGANIZATION
         Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

    5.   SOLE VOTING POWER
         3,676,260**

    6.   SHARED VOTING POWER
         -0-

    7.   SOLE DISPOSITIVE POWER
         3,676,260**

    8.   SHARED DISPOSITIVE POWER
         -0-

    9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
PERSON
         3,676,260**

    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)
    11.0%**

12. TYPE OF REPORTING PERSON
    IA, HC

**  See Item 4 of this filing


Item 1.

    (a). Name of Issuer: Blackboard Inc. ("Blackboard")

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

         650 Massachusetts Ave, N.W.
         Washington, DC 20001

Item 2.

    (a).-(c). Name, Principal Business Address, and Citizenship of
Persons
              Filing:

         (1)  Janus Capital Management LLC ("Janus Capital")
              151 Detroit Street
              Denver, Colorado  80206
              Citizenship:  Delaware

    (d). Title of Class of Securities:  Common Stock

    (e). CUSIP Number:  091935502

Item 3.

This statement is filed pursuant to Rule 13d-1 (b) or 13d-2(b) and
the person
filing, Janus Capital, is an investment adviser in accordance with
Section 240.13d-1(b)(ii)(E) as well as a parent holding
company/control person in accordance with Section 240.13d-
1(b)(ii)(G).  See Item 4 for additional information.

Item 4.  Ownership

The information in items 1 and 5 through 11 on the cover page(s)
on Schedule 13G
is hereby incorporated by reference.

Janus Capital has a direct 91.8% ownership stake in INTECH
Investment Management ("INTECH") and a direct 77.8% ownership
stake in Perkins Investment Management LLC ("Perkins").  Due to
the above ownership structure, holdings for Janus Capital, Perkins
and INTECH are aggregated for purposes of this filing. Janus
Capital, Perkins and INTECH are registered investment advisers,
each furnishing investment advice to various investment companies
registered under Section 8 of the Investment Company Act of 1940
and to individual and institutional clients (collectively referred
to herein as "Managed Portfolios").

As a result of its role as investment adviser or sub-adviser to
the Managed Portfolios, Janus Capital may be deemed to be the
beneficial owner of 3,676,260 shares or 11.0% of the shares
outstanding of Blackboard Common Stock held by such Managed
Portfolios.  However, Janus Capital does not have the right to
receive any dividends from, or the proceeds from the sale of, the
securities held in the Managed Portfolios and disclaims any
ownership associated with such rights.

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 Managed Portfolios, set forth in Item 4 above, have the right
to receive all
dividends from, and the proceeds from the sale of, the securities
held in their respective accounts.

The interest of any one such person does not exceed 5% of the
class of securities.

These shares were acquired in the ordinary course of business, and
not with the purpose of changing or influencing control of the
Issuer.

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.

Item 10. Certification

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


SIGNATURES

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.

JANUS CAPITAL MANAGEMENT LLC

By  /s/  David R. Kowalski                           3/10/2010
  David R. Kowalski,                                 Date
    Senior Vice President and CCO