Morgan, Lewis & Bockius LLP
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www.morganlewis.com

[___________], 2015

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 [________], 2015, by and
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among Pioneer Bond Fund, a Delaware statutory trust (the "Acquiring Fund"), and
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Pioneer Series Trust IV, a Delaware statutory trust (the "Acquired Trust"), on
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behalf of its series, Pioneer Government Income Fund (the "Acquired Fund"). All
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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 [_______, 2015], and related documents
(collectively, the "Transaction Documents"). In that
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  Almaty  Astana  Beijing Boston  Brussels  Chicago  Dallas  Dubai  Frankfurt
  Harrisburg  Hartford Houston  London  Los Angeles  Miami  Moscow  New  York
  Orange  County  Paris  Philadelphia  Pittsburgh   Princeton  San  Francisco
          Santa Monica  Silicon Valley Tokyo  Washington  Wilmington



Pioneer Bond Fund
Pioneer Series Trust IV
[________], 2015
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
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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
[________], 2015
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
[________], 2015
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,



MORGAN, LEWIS & BOCKIUS LLP