EXHIBIT 5

                                March 29, 2007

Banc of America Mortgage Securities, Inc.
214 North Tryon Street
Charlotte, North Carolina  28255

      Re:   Banc of America Alternative Loan Trust 2007-1, Mortgage Pass-Through
            Certificates, Series 2007-1, Senior, Class M, Class B-1, Class B-2
            and Class B-3 Certificates

Ladies and Gentlemen:

            We have acted as special counsel to Banc of America Mortgage
Securities, Inc. (the "Company") in connection with the proposed sale by the
Company and purchase by Banc of America Securities LLC, as underwriter (the
"Underwriter"), of Banc of America Alternative Loan Trust 2007-1, Mortgage
Pass-Through Certificates, Series 2007-1, Class 1-A-1, Class 2-A-1, Class 2-A-2,
Class 3-A-1, Class 3-A-2, Class 3-A-3, Class 3-A-4, Class 3-A-5, Class 3-A-6,
Class 3-A-7, Class 3-A-8, Class 3-A-9, Class 3-A-10, Class 3-A-11, Class 3-A-12,
Class 3-A-13, Class 3-A-14, Class 3-A-15, Class 3-A-16, Class 3-A-17, Class
3-A-18, Class 3-A-19, Class 3-A-20, Class 3-A-21, Class 3-A-22, Class 3-A-23,
Class 3-A-24, Class 3-A-25, Class 3-A-26, Class 3-A-27, Class 3-A-28, Class
3-A-29, Class 3-A-30, Class 3-A-31, Class 3-A-32, Class 3-A-33, Class 3-A-34,
Class 3-A-35, Class 3-A-R, Class 3-IO, Class 3-PO, Class 4-A-1, Class M, Class
B-1, Class B-2 and Class B-3 (collectively, the "Certificates"), pursuant to the
terms of the underwriting agreement, dated March 28, 2007 (the "Underwriting
Agreement"), among the Company, Bank of America, National Association and the
Underwriter. The Certificates are being issued pursuant to a Pooling and
Servicing Agreement, dated March 29, 2007 (the "Pooling and Servicing
Agreement"), among the Company, Bank of America, National Association, as
servicer (the "Servicer"), and Wells Fargo Bank, N.A., as trustee (the
"Trustee"). Capitalized terms used herein but not defined herein have the
respective meanings given them in the Underwriting Agreement.

            In rendering the opinions set forth below, we have examined and
relied upon the originals, copies or specimens, certified or otherwise
identified to our satisfaction, of the Transaction Documents (as defined below)
and such certificates, corporate and public records, agreements and instruments
and other documents, including, among other things, the documents delivered on
the date hereof, as we have deemed appropriate as a basis for the opinions
expressed below. In such examination we have assumed the genuineness of all
signatures, the authenticity of all documents, agreements and instruments
submitted to us as originals, the conformity to original documents, agreements
and instruments of all documents, agreements and instruments submitted to us as
copies or specimens, the authenticity of the originals of such documents,
agreements and instruments submitted to us as copies or specimens, the
conformity of the text of each document filed with the Securities and Exchange
Commission (the "Commission") through the Commission's Electronic Data
Gathering, Analysis and Retrieval System to the printed document reviewed by us,
and the accuracy of the matters set forth in the documents, agreements and
instruments we reviewed. As to matters of fact relevant to the opinions
expressed herein, we have relied upon, and assumed the accuracy of, the
representations and warranties contained in the Underwriting Agreement and the
Pooling and Servicing Agreement and we have relied upon certificates and oral or
written statements and other information obtained from the Company, the other
parties to the transaction referenced herein, and public officials. Except as
expressly set forth herein, we have not undertaken any independent investigation
(including, without limitation, conducting any review, search or investigation
of any public files, records or dockets) to determine the existence or absence
of the facts that are material to our opinions, and no inference as to our
knowledge concerning such facts should be drawn from our reliance on the
representations of the Company in connection with the preparation and delivery
of this letter.

            In particular, we have examined and relied upon: (i) the Prospectus,
dated March 28, 2007 (the "Prospectus") and the Prospectus Supplement, dated
March 28, 2007 (the "Prospectus Supplement"), relating to the offering of the
Certificates and (ii) the Pooling and Servicing Agreement.

            Items (i) and (ii) above are referred to in this letter as the
"Transaction Documents."

            We have also assumed that all documents, agreements and instruments
have been duly authorized, executed and delivered by all parties thereto, that
all such parties are validly existing and in good standing under the laws of
their respective jurisdictions of organization, that all such parties had the
power and legal right to execute and deliver all such documents, agreements and
instruments, and (other than with respect to the Company) that such documents,
agreements and instruments are legal, valid and binding obligations of such
parties, enforceable against such parties in accordance with their respective
terms. As used herein, "to our knowledge," "known to us" or words of similar
import mean the actual knowledge, without independent investigation, of any
lawyer in our firm actively involved in the transactions contemplated by the
Underwriting Agreement.

            We express no opinion concerning the laws of any jurisdiction other
than the laws of the State of New York and, to the extent expressly referred to
in this letter, the federal laws of the United States of America.

            Based upon and subject to the foregoing, we are of the opinion that:

            1. The Certificates have been duly authorized by the Company, and
      when the Certificates have been duly executed and authenticated by the
      Trustee and paid for and sold to the Underwriter as contemplated in the
      Prospectus and Prospectus Supplement, the Certificates will be legally
      issued, fully paid and non-assessable; and

            2. The descriptions of federal income tax consequences appearing
      under the heading "Federal Income Tax Consequences" in the Prospectus and
      in the Prospectus Supplement accurately describe the material federal
      income tax consequences to holders of the Certificates, under existing law
      and subject to the qualifications and assumptions stated therein. We also
      hereby confirm and adopt the opinions expressly set forth under such
      headings, under existing law and subject to the qualifications and
      assumptions stated therein.

            We hereby consent to the filing of this letter as an exhibit to the
Company's Registration Statement on Form S-3 (File No. 333-132249) (the
"Registration Statement") filed with the Securities and Exchange Commission, as
it relates to the Certificates and to the reference to this firm under the
headings "Legal Matters" and "Federal Income Tax Consequences" in the Prospectus
and the Prospectus Supplement. This consent is not to be construed as an
admission that we are a person whose consent is required to be filed with the
Registration Statement under the provisions of the Securities Act of 1933, as
amended.

            No opinion has been sought and none has been given concerning the
tax treatment of the issuance and sale of the Certificates under the laws of any
state. In addition, we disclaim any obligation to update this letter for changes
in fact or law, or otherwise.

                                       Very truly yours,



                                       /s/ Cadwalader, Wickersham & Taft LLP