Exhibit 4


- --------------------------------------------------------------------------------

                   BANC OF AMERICA MORTGAGE SECURITIES, INC.,
                                  as Depositor

                     BANK OF AMERICA, NATIONAL ASSOCIATION,
                                   as Servicer

                                       and

                             WELLS FARGO BANK, N.A.,
                                   as Trustee

                                 AMENDMENT No. 1

                               Dated June 20, 2006

                                       To

                         POOLING AND SERVICING AGREEMENT
                             Dated January 30, 2006

                             -----------------------

                  Banc of America Alternative Loan Trust 2006-1
                       Mortgage Pass-Through Certificates

                                  Series 2006-1

- --------------------------------------------------------------------------------


            AMENDMENT No. 1, dated June 20, 2006 (the "Amendment"), to the
Pooling and Servicing Agreement, dated January 30, 2006 (the "Agreement"), among
BANC OF AMERICA MORTGAGE SECURITIES, INC., as depositor (the "Depositor"), BANK
OF AMERICA, NATIONAL ASSOCIATION, as servicer (the "Servicer"), and WELLS FARGO
BANK, N.A., as trustee (the "Trustee").

            WHEREAS, Section 11.01 of the Agreement provides, among other
things, that the Depositor, the Servicer and the Trustee may amend the
Agreement, without the consent of any of the Certificateholders, to make any
other provisions with respect to matters or questions arising under the
Agreement which shall not be materially inconsistent with the provisions of the
Agreement, provided that such action shall not, as evidenced by an Opinion of
Counsel, adversely affect in any material respect the interests of any
Certificateholder;

            WHEREAS, the Depositor, the Servicer and the Trustee desire to amend
the Agreement, as set forth in this Amendment, and have obtained the Opinion of
Counsel required by Section 11.01 of the Agreement; and

            NOW THEREFORE, in consideration of the mutual agreements herein
contained, the Depositor, the Servicer and the Trustee agree as follows:

            All terms used in this Amendment which are defined in the Agreement,
either directly or by reference therein, have the meanings assigned to them
therein, except to the extent such terms are defined or modified in this
Amendment or the context clearly requires otherwise.

            Section 1. Amendment of Section 2.04. Section 2.04 of the Agreement
is hereby amended as follows:

(a)   By inserting the following language as clause (li):

      "(li) No Mortgage Loan is a High Cost Loan or Covered Loan, as applicable
      (as such terms are defined in the then-current S&P's LEVELS(R) Glossary
      which is now Version 5.6(d), Appendix E), and no Mortgage Loan originated
      on or after October 1, 2002 through March 6, 2003 is governed by the
      Georgia Fair Lending Act."

(b) By deleting the second and third sentences of the last paragraph of Section
2.04 in their entirety and replacing them with the following:

      "Within 90 days of its discovery or its receipt of notice of any such
      breach (other than with respect to a breach of the representations and
      warranties set forth in clause (li) of this Section 2.04), the Depositor
      shall cure such breach in all material respects or shall either (i)
      repurchase the Mortgage Loan or any property acquired in respect thereof
      from the Trustee at a price equal to the Repurchase Price or (ii) if
      within two years of the Closing Date, substitute for such Mortgage Loan in
      the manner described in Section 2.02; provided that if the breach would
      cause the Mortgage Loan to be other than a "qualified mortgage" as defined
      in Section 860G(a)(3) of the Code, any such repurchase or substitution
      must occur within 90 days from the date the breach was discovered. In
      addition to the foregoing, if a breach of the representation set forth in
      clauses (vi) or (li) of this Section 2.04 occurs as a result of a
      violation of an applicable predatory or abusive lending law, the Depositor
      shall reimburse the Trust for all costs or damages incurred by the Trust
      as a result of the violation of such law (such amount, the "Reimbursement
      Amount")."

            Section 2. Counterparts. This Amendment may be executed in any
number of counterparts, each of which when so executed shall be deemed to be an
original, but all of such counterparts shall together constitute but one and the
same instrument.

            Section 3. Ratification of Agreement. Except as modified and
expressly amended by this Amendment, the Agreement is in all respects ratified
and confirmed, and all the terms, provisions and conditions thereof shall be and
remain in full force and effect.

            Section 4. Governing Law. THIS AMENDMENT SHALL BE CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, WITHOUT APPLICATION OF THE
CONFLICTS OF LAWS PROVISIONS THEREOF, AND THE OBLIGATIONS, RIGHTS AND REMEDIES
OF THE PARTIES HEREUNDER SHALL BE DETERMINED IN ACCORDANCE WITH SUCH LAWS.


            IN WITNESS WHEREOF, the Depositor, the Servicer and the Trustee have
caused their names to be signed hereto by their respective officers thereunto
duly authorized, all as of the day and year first above written.


                               BANC OF AMERICA MORTGAGE SECURITIES, INC.,
                               as Depositor


                               By:   /s/ Judy Lowman
                                  --------------------------------
                                  Name:  Judy Lowman
                                  Title: Senior Vice President


                               BANK OF AMERICA, NATIONAL ASSOCIATION,
                               as Servicer


                               By:   /s/ Stephan A. Cummings
                                  --------------------------------
                                  Name:  Stephen A. Cummings
                                  Title: Senior Vice President


                               WELLS FARGO BANK, N. A.,
                               as Trustee

                               By:   /s/ Christopher Regnier
                                  --------------------------------
                                  Name:  Christopher Regnier
                                  Title: Vice President


STATE OF KANSAS     )
                    )     ss.:
COUNTY OF JOHNSON   )

            On this 20th day of June, 2006, before me, a notary public in and
for the State of Kansas, personally appeared Judy Lowman, known to me who, being
by me duly sworn, did depose and say that she is a Senior Vice President of Banc
of America Mortgage Securities, Inc., a Delaware corporation, one of the parties
that executed the foregoing instrument; and that she signed her name thereto by
order of the Board of Directors of said corporation.



                                            -------------------------
                                                 Notary Public


[NOTARIAL SEAL]
My commission expires ____________.


STATE OF NORTH CAROLINA )
                        )     ss.:
COUNTY OF MECKLENBURG   )


            On this 20th day of June, 2006, before me, a notary public in and
for the State of North Carolina, personally appeared Stephen A. Cummings, known
to me who, being by me duly sworn, did depose and say that he is a Senior Vice
President of Bank of America, National Association, a national banking
association, one of the parties that executed the foregoing instrument; and that
he signed his name thereto by order of the Board of Directors of such
association.



                                            -------------------------
                                                 Notary Public


[NOTARIAL SEAL]
My commission expires ____________.


STATE OF MARYLAND   )
                    )     ss.:
COUNTY OF   HOWARD  )


            On this 20th day of June, 2006, before me, a notary public in and
for the State of Maryland, personally appeared Christopher Regnier, known to me
who, being by me duly sworn, did depose and say that he is a Vice President of
Wells Fargo Bank, N.A., a national banking association, one of the parties that
executed the foregoing instrument; and that he signed his name thereto by order
of the Board of Directors of such association.



                                            -------------------------
                                                 Notary Public


[NOTARIAL SEAL]
My commission expires ____________.