485BPOS

    As filed with the Securities and Exchange Commission on November 4, 2016

                                                         File No. 333-208696

                                  United States
                       Securities and Exchange Commission
                             Washington, D.C. 20549

                                    FORM N-14

             REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

                         Pre-Effective Amendment No. ___

                        Post-Effective Amendment No. 2

                        (Check appropriate box or boxes)

                                PIONEER BOND FUND

               (Exact Name of Registrant as Specified in Charter)

                                 (617) 742-7825
                        (Area Code and Telephone Number)

                  60 State Street, Boston, Massachusetts 02109
 (Address of Principal Executive Offices: Number, Street, City, State, Zip Code)

                                 Terrence Cullen
                       Pioneer Investment Management, Inc.
                                 60 State Street
                           Boston, Massachusetts 02109
                     (Name and Address of Agent for Service)

                        Copies to: Roger P. Joseph, Esq.
                           Morgan, Lewis & Bockius LLP
                               One Federal Street
                           Boston, Massachusetts 02110

Approximate Date of Proposed Public Offering: As soon as practicable after the
effective date of this Registration Statement.

Calculation of Registration Fee under the Securities Act of 1933: No filing fee
is due because of reliance on Section 24(f) of the Investment Company Act of
1940, which permits registration of an indefinite number of securities.

Title of Securities Being Registered: Shares of beneficial interest of Pioneer
Bond Fund, a series of the Registrant.

It is proposed that this filing will become effective on November 4, 2016,
pursuant to Rule 485(b) under the Securities Act of 1933, as amended.



Part A - Prospectus/Proxy Statement and Part B - Statement of Additional
Information are incorporated by reference to Post-Effective Amendment No. 1 to
the Registrant's Registration Statement on Form N-14 as filed with the
Securities and Exchange Commission on February 1, 2016.




                                     PART C

                                OTHER INFORMATION
                                PIONEER BOND FUND

ITEM 15. INDEMNIFICATION

No change from the information set forth in Item 30 of the most recently filed
Registration Statement of Pioneer Bond Fund (the "Registrant") on Form N-1A
under the Securities Act of 1933 and the Investment Company Act of 1940 (File
Nos. 002-62436 and 811-02864), as filed with the Securities and Exchange
Commission on October 28, 2016 (Accession No. 0000276776-16-000186), which
information is incorporated herein by reference.

ITEM 16. EXHIBITS

(1)(a)   Amended and Restated Agreement and Declaration of Trust            (15)
(1)(b)   Certificate of Trust                                                (1)
(2)      Amended and Restated By-Laws                                        (7)
(3)      Not applicable
(4)      Form of Agreement and Plan of Reorganization                        (*)
(5)      Reference is made to Exhibits (1) and (2) hereof
(6)(a)   Amended and Restated Management Agreement (November 12, 2013)      (11)
(6)(b)   Expense Limit Agreement                                            (15)
(7)(a)   Underwriting Agreement                                              (2)
(7)(b)   Dealer Sales Agreement                                              (6)
(8)      Not applicable
(9)(a)   Custodian Agreement between the Trust and Brown Brothers            (5)
         Harriman & Co.
(9)(b)   Amended Appendix A to Custodian Agreement (December 10, 2014)      (12)
(9)(c)   Amendment to Custodian Agreement (May 31, 2016)                    (15)
(10)(a)  Amended and Restated Pioneer Funds Distribution Plan               (12)
         (November 10, 2014)
(10)(b)  Class R Service Plan                                                (4)
(10)(c)  Multi-Class Plan Pursuant to Rule 18f-3                            (10)
(11)     Opinion of Counsel (legality of securities being offered)          (13)
(12)     Final opinion as to tax matters and consent                        (**)
(13)(a)  Investment Company Service Agreement                                (5)
(13)(b)  Amendment No. 8 to Master Investment Company Service Agreement     (12)
         (December 10, 2014)
(13)(c)  Amended and Restated Administration Agreement (August 1, 2014)     (12)
(13)(d)  Administrative Agency Agreement (March 5, 2012)                     (9)
(13)(e)  Appendix A to Administrative Agency Agreement (April 1, 2016)      (15)
(14)     Consent of Independent Registered Public Accounting Firm           (14)
(15)     Not applicable
(16)     Powers of Attorney                                                 (13)
(17)(a)  Code of Ethics of the Pioneer Funds, Pioneer Funds Distributor,    (11)
         Inc., Pioneer Institutional Asset Management, Inc., and Pioneer
         Investment Management, Inc. (September 20, 2013)
(17)(b)  Prospectus of Pioneer Bond Fund dated November 1, 2015, as         (13)
         supplemented, and Statement of Additional Information of Pioneer
         Bond Fund dated November 1, 2015, as supplemented.
(17)(c)  Prospectus of Pioneer Government Income Fund dated December 1,     (13)
         2015, as supplemented, and Statement of Additional Information
         of Pioneer Government Income Fund dated December 1, 2015, as
         supplemented.
(17)(d)  Annual Report of Pioneer Bond Fund for the fiscal year ended       (13)
         June 30, 2015.
(17)(e)  Annual Report of Pioneer Government Income Fund for the fiscal     (13)
         year ended July 31, 2015.

(1) Previously filed. Incorporated herein by reference from the exhibits filed
with Post-Effective Amendment No. 28 to the Registrant's Registration Statement
(File No. 2-62436) with the Securities and Exchange Commission (the "SEC") on
May 14, 1999 (Accession No. 0000276776-99-000013).

(2) Previously filed. Incorporated by reference from the exhibits filed with
Post-Effective Amendment No. 34 to the Registrant's Registration Statement with
the SEC on October 29, 2001 (Accession No. 0000276776-01-500036).

(3) Previously filed. Incorporated by reference from the exhibits filed with
Post-Effective Amendment No. 35 to the Registrant's Registration Statement with
the SEC on October 29, 2002 (Accession No. 0000276776-03-000002).

(4) Previously filed. Incorporated by reference from the exhibits filed with
Post-Effective Amendment No. 36 to the Registrant's Registration Statement with
the SEC on February 24, 2003 (Accession No. 0000276776-03-000002).

(5) Previously filed. Incorporated herein by reference from the exhibits filed
with the Post-Effective Amendment No. 42 to the Registrant's Registration
Statement on Form N-1A (File Nos. 2-62436 and 811-02864) as filed with the SEC
on October 27, 2006 (Accession No. 0000276776-06-000037).

(6) Previously filed. Incorporated herein by reference from the exhibits filed
with the Post-Effective Amendment No. 43 to the Registrant's Registration
Statement on Form N-1A (File Nos. 2-62436 and 811-02864) as filed with the SEC
on July 3, 2007 (Accession No. 0000276776-07-000075).

(7) Previously filed. Incorporated herein by reference from the exhibits filed
with the Post-Effective Amendment No. 45 to the Registrant's Registration
Statement on Form N-1A (File Nos. 2-62436 and 811-02864) as filed with the SEC
on October 27, 2008 (Accession No. 0000276776-08-000052).

(8) Previously filed. Incorporated herein by reference from the exhibits filed
with the Post-Effective Amendment No. 48 to the Registrant's Registration
Statement on Form N-1A (File Nos. 2-62436 and 811-02864) as filed with the SEC
on October 28, 2010 (Accession No. 0000276776-10-000023).

(9) Previously filed. Incorporated herein by reference from the exhibits filed
with the Post-Effective Amendment No. 51 to the Registrant's Registration
Statement on Form N-1A (File Nos. 2-62436 and 811-02864) as filed with the SEC
on October 26, 2012 (Accession No. 0000276776-12-000032).

(10) Previously filed. Incorporated herein by reference from the exhibits filed
with the Post-Effective Amendment No. 53 to the Registrant's Registration
Statement on Form N-1A (File Nos. 2-62436 and 811-02864) as filed with the SEC
on December 14, 2012 (Accession No. 0000276776-12-000042).

(11) Previously filed. Incorporated herein by reference from the exhibits filed
with the Post-Effective Amendment No. 57 to the Registrant's Registration
Statement on Form N-1A (File Nos. 2-62436 and 811-02864) as filed with the SEC
on October 1, 2014 (Accession No. 0000276776-14-000098).

(12) Previously filed. Incorporated herein by reference from the exhibits filed
with the Post-Effective Amendment No. 59 to the Registrant's Registration
Statement on Form N-1A (File Nos. 2-62436 and 811-02864) as filed with the SEC
on October 28, 2015 (Accession No. 0000276776-15-000106).

(13) Previously filed. Incorporated herein by reference from the exhibits filed
with the Registrant's Registration Statement on Form N-14 (File No. 333-208696)
as filed with the SEC on December 22, 2015 (Accession No. 0000276776-15-000123).

(14) Previously filed. Incorporated herein by reference from the exhibits filed
with the Registrant's Post-Effective Amendment No. 1 to the Registration
Statement on Form N-14 (File No. 333-208696) as filed with the SEC on
February 1, 2016 (Accession No. 0000276776-16-000128).

(15) Previously filed. Incorporated herein by reference from the exhibits filed
with the Post-Effective Amendment No. 61 to the Registrant's Registration
Statement on Form N-1A (File Nos. 2-62436 and 811-02864) as filed with the SEC
on October 28, 2016 (Accession No. 0000276776-16-000186).

(*) Attached as Exhibit A to the combined Information Statement/Prospectus

(**) Filed herewith.

ITEM 17. UNDERTAKINGS.

(1) The undersigned Registrant agrees that prior to any public reoffering of the
securities registered through the use of a prospectus which is part of this
Registration Statement by any person or party which is deemed to be an
underwriter within the meaning of Rule 145(c) of the Securities Act of 1933, the
reoffering prospectus will contain the information called for by the applicable
registration form for the reofferings by persons who may be deemed underwriters,
in addition to the information called for by the other items of the applicable
form.

(2) The undersigned Registrant agrees that every prospectus that is filed under
paragraph (1) above will be filed as part of an amendment to the Registration
Statement and will not be used until the amendment is effective, and that, in
determining any liability under the Securities Act of 1933, each post-effective
amendment shall be deemed to be a new registration statement for the securities
offered therein, and the offering of the securities at that time shall be deemed
to be the initial bona fide offering of them.

(3) The undersigned Registrant agrees that it shall file a final executed
version of the legal and consent opinion as to tax matters as an exhibit to the
subsequent post-effective amendment to its registration statement on Form N-14
filed with the SEC upon the closing of the reorganization contemplated by this
Registration Statement on Form N-14.

(4) Insofar as indemnification for liability arising under the Securities Act of
1933 may be permitted to directors, officers and controlling persons of the
Registrant pursuant to the foregoing provisions, or otherwise the Registrant has
been advised that in the opinion of the Securities and Exchange Commission such
indemnification is against public policy as expressed in the Act and is,
therefore, unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by the Registrant of expenses incurred
or paid by a director, officer or controlling person of the Registrant in the
successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Act and will be governed by the final adjudication of
such issue.



                                   SIGNATURES

    Pursuant to the requirements of the Securities Act of 1933, as amended, the
Registrant certifies that it meets all of the requirements for effectiveness of
this Amendment to the Registration Statement on Form N-14 pursuant to Rule
485(b) under the Securities Act of 1933, as amended, and has duly caused this
Amendment to be signed on its behalf by the undersigned, thereunto duly
authorized, on the 2nd day of November, 2016.

            PIONEER BOND FUND

        By: /s/ Lisa M. Jones
            --------------------------
            Name:  Lisa M. Jones
            Title: President

     Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below by the following persons in the
capacities and on the dates indicated.



Signature                  Title                                          Date
---------                  -----                                          ----
                                                                    
/s/ Lisa M. Jones          President (Principal Executive Officer)        November 4, 2016
-------------------------
Lisa M. Jones

/s/ Mark E. Bradley        Treasurer (Principal Financial and Accounting  November 4, 2016
-------------------------  Officer)
Mark E. Bradley

/s/ David R. Bock*         Trustee                                        November 4, 2016
-------------------------
David R. Bock

/s/ Benjamin M. Friedman*  Trustee                                        November 4, 2016
-------------------------
Benjamin M. Friedman

/s/ Margaret B.W. Graham*  Trustee                                        November 4, 2016
-------------------------
Margaret B.W. Graham

/s/ Thomas J. Perna*       Chairman of the Board and Trustee              November 4, 2016
-------------------------
Thomas J. Perna

/s/ Marguerite A. Piret*   Trustee                                        November 4, 2016
-------------------------
Marguerite A. Piret

/s/ Fred J. Ricciardi*     Trustee                                        November 4, 2016
-------------------------
Fred J. Ricciardi

/s/ Kenneth J. Taubes*     Trustee                                        November 4, 2016
-------------------------
Kenneth J. Taubes


* By: /s/ Lisa M. Jones
      ---------------------------------------
      Lisa M. Jones, Attorney-in-Fact



                                  EXHIBIT INDEX

The following exhibits are filed as part of this Registration Statement:

Exhibit No.    Description
-----------    -----------

(12)           Final opinion as to tax matters and consent

EX-99.12 TAX OPINION

                         Morgan, Lewis & Bockius LLP
                              One Federal Street
                            Boston, MA 02110-1726

March 18, 2016

Pioneer Bond Fund
60 State Street
Boston, Massachusetts 02109

Pioneer Series Trust IV
60 State Street
Boston, Massachusetts 02109

Ladies and Gentlemen:

This opinion is furnished to you pursuant to Paragraph 8.4 of the Agreement and
Plan of Reorganization (the "Agreement"), dated as of March 18, 2016, by and
among Pioneer Bond Fund, a Delaware statutory trust (the "Acquiring Fund"), and
Pioneer Series Trust IV, a Delaware statutory trust (the "Acquired Trust"), on
behalf of its series, Pioneer Government Income Fund (the "Acquired Fund"). All
capitalized terms not otherwise defined herein have the meanings ascribed to
them in the Agreement. The Agreement contemplates (1) the transfer of all of
the Acquired Assets to the Acquiring Fund in exchange solely for (a) the
issuance to the Acquired Fund of a number of Class A, Class C, and Class Y
Acquiring Fund Shares, including fractional Acquiring Fund Shares, having an
aggregate NAV equal as to each class to the NAV of the Acquired Fund
attributable to the corresponding class of Acquired Fund Shares, and (b) the
assumption by the Acquiring Fund of all the Assumed Liabilities, and (2) the
distribution by the Acquired Fund of the Acquiring Fund Shares pro rata on a
class-by-class basis to the Acquired Fund Shareholders in complete liquidation
and dissolution of the Acquired Fund (collectively, the "Transaction").

In connection with this opinion we have examined and relied upon the originals
or copies, certified or otherwise identified to us to our satisfaction, of the
Agreement, the Combined Information Statement of the Acquired Fund and
Prospectus for the Acquiring Fund, dated February 1, 2016, and related
documents (collectively, the "Transaction Documents"). In that



Pioneer Bond Fund
Pioneer Series Trust IV
March 18, 2016
Page Two

examination, we have assumed the genuineness of all signatures, the capacity
and authority of each party executing a document to so execute the document,
the authenticity and completeness of all documents purporting to be originals
(whether reviewed by us in original or copy form) and the conformity to the
originals of all documents purporting to be copies (including electronic
copies). We have also assumed that each agreement and other instrument reviewed
by us is valid and binding on the party or parties thereto and is enforceable
in accordance with its terms, and that there are no contracts, agreements,
arrangements, or understandings, either written or oral, that are inconsistent
with or that would materially alter the terms of the Agreement or the other
Transaction Documents.

As to certain factual matters, we have relied with your consent upon, and our
opinion is limited by, the representations of the various parties set forth in
the Transaction Documents and in the Acquired Fund Tax Representation
Certificate and the Acquiring Fund Tax Representation Certificate, each dated
as of the date hereof (the "Certificates"). Our opinion assumes (i) that all
representations set forth in the Transaction Documents and in the Certificates
will be true and correct in all material respects as of the date of the
Transaction (and that any such representations made "to the best knowledge of",
"to the knowledge of", "in the belief of", or otherwise similarly qualified,
are true and correct in all material respects without any such qualification),
and (ii) that the Agreement is implemented in accordance with its terms and
consistent with the representations set forth in the Transaction Documents and
Certificates. Our opinion is limited solely to the provisions of the Internal
Revenue Code of 1986, as amended and as presently in effect (the "Code"),
existing case law, existing permanent and temporary treasury regulations
promulgated under the Code, and existing published revenue rulings and
procedures of the Internal Revenue Service that are in effect as of the date
hereof, all of which are subject to change and new interpretation, both
prospectively and retroactively. We assume no obligation to update our opinion
to reflect other facts or any changes in law or in the interpretation thereof
that may hereafter occur.

On the basis of and subject to the foregoing, with respect to the Transaction,
we are of the opinion that, for United States federal income tax purposes:

    1. The Transaction will constitute a "reorganization" within the meaning of
       Section 368(a) of the Code, and each of the Acquired Fund and the
       Acquiring Fund will be a "party to a reorganization" within the meaning
       of Section 368(b) of the Code.

    2. No gain or loss will be recognized by the Acquired Fund upon the
       transfer of the Acquired Assets to the Acquiring Fund in the Transaction
       solely in exchange for the Acquiring Fund Shares and the assumption by
       the Acquiring Fund of the Assumed Liabilities, or upon the distribution
       of the Acquiring Fund Shares by the Acquired Fund to the Acquired Fund
       Shareholders in complete liquidation of the



Pioneer Bond Fund
Pioneer Series Trust IV
March 18, 2016
Page Three

       Acquired Fund, except for (A) gain or loss that may be recognized with
       respect to "section 1256 contracts" as defined in Section 1256(b) of the
       Code, (B) gain that may be recognized with respect to stock in a
       "passive foreign investment company" as defined in Section 1297(a) of
       the Code, and (C) any other gain or loss that may be required to be
       recognized (i) as a result of the closing of the Acquired Fund's taxable
       year or (ii) upon the transfer of an Acquired Asset regardless of
       whether such transfer would otherwise be a non-recognition transaction
       under the Code.

    3. The tax basis in the hands of the Acquiring Fund of the Acquired Assets
       will be the same as the tax basis of such Acquired Assets in the hands
       of the Acquired Fund immediately prior to the transfer thereof,
       increased by the amount of gain (or decreased by the amount of loss), if
       any, recognized by the Acquired Fund upon the transfer.

    4. The holding period in the hands of the Acquiring Fund of each Acquired
       Asset transferred in the Transaction, other than Acquired Assets with
       respect to which gain or loss is required to be recognized in the
       Transaction, will include the period during which the Acquired Asset was
       held by the Acquired Fund (except where investment activities of the
       Acquiring Fund have the effect of reducing or eliminating the holding
       period with respect to an Acquired Asset).

    5. No gain or loss will be recognized by the Acquiring Fund upon its
       receipt of the Acquired Assets solely in exchange for the Acquiring Fund
       Shares and the assumption by the Acquiring Fund of the Assumed
       Liabilities.

    6. No gain or loss will be recognized by the Acquired Fund Shareholders
       upon the exchange of all their Acquired Fund Shares solely for Acquiring
       Fund Shares as part of the Transaction.

    7. The aggregate tax basis of the Acquiring Fund Shares that each Acquired
       Fund Shareholder receives in the Transaction will be the same as the
       aggregate tax basis of the Acquired Fund Shares exchanged therefor.

    8. Each Acquired Fund Shareholder's holding period for the Acquiring Fund
       Shares received in the Transaction will include the holding period for
       the Acquired Fund Shares exchanged therefor, provided that the Acquired
       Fund Shareholder held such Acquired Fund Shares as capital assets on the
       date of the exchange.



Pioneer Bond Fund
Pioneer Series Trust IV
March 18, 2016
Page Four

This opinion is being delivered solely to you for your use in connection with
the Transaction, and may not be relied upon by any other person or used for any
other purpose.

Very truly yours,

/s/ Morgan, Lewis & Bockius LLP

MORGAN, LEWIS & BOCKIUS LLP