EXHIBIT 5.1




                   [Letterhead of Thacher Proffitt & Wood LLP]


May 28, 2004



Impac Secured Assets Corp.                 Impac Funding Corporation
1401 Dove Street                           1401 Dove Street
Newport Beach, California 92660            Newport Beach, California 92660

Impac Mortgage Holdings, Inc.              Standard & Poor's, A Division of The
1401 Dove Street                           McGraw-Hill Companies, Inc.
Newport Beach, California 92660            55 Water Street, 41st Floor
                                           New York, New York 10041

Countrywide Securities Corporation         UBS Securities LLC
4500 Park Granada                          1285 Avenue of the Americas
Calabasas, California 91302                New York, New York 10019

                  Opinion: Underwriting Agreement
                  Impac Secured Assets Corp.
                  Mortgage Pass-Through Certificates, Series 2004-2
                  -------------------------------------------------

Ladies and Gentlemen:

                  We have acted as counsel to Impac Funding Corporation (the
"Seller"), Impac Secured Assets Corp. (the "Depositor") and Impac Mortgage
Holdings, Inc. ("IMH") in connection with (i) the Mortgage Loan Purchase
Agreement, dated as of May 1, 2004 (the "Seller Sale Agreement"), among the
Seller, the Depositor and IMH, (ii) the Pooling and Servicing Agreement, dated
as of May 1, 2004 (the "Pooling and Servicing Agreement"), among the Seller (in
such capacity, the "Master Servicer"), the Depositor and Deutsche Bank National
Trust Company (the "Trustee"), and the certificates issued pursuant thereto
designated as Mortgage Pass-Through Certificates, Series 2004-2 (collectively,
the "Certificates"), (iii) the Underwriting Agreement, dated May 26, 2004 (the
"Underwriting Agreement"), among the Seller, the Depositor, IMH, Countrywide
Securities Corporation ("Countrywide") and UBS Securities LLC ("UBS", and
together with Countrywide, the "Underwriters") pursuant to which certain
Certificates were sold, (iv) the Purchase Agreement, dated May 28, 2004 (the
"Purchase Agreement"), among the Seller, the Depositor, IMH and Countrywide (the
"Purchaser") pursuant to which certain Certificates were sold (the
"Certificates"), (v) the Prospectus Supplement, dated May 26, 2004 (the
"Prospectus Supplement") and the Base Prospectus to which it relates, dated
February 25, 2003 (the "Base Prospectus"; together with the Prospectus
Supplement, the "Prospectus") and (vi) the Private Placement Memorandum, dated
May 28, 2004 (the "Private Placement Memorandum"). The Seller Sale Agreement,
the





Impac Secured Assets Corp., Series 2004-2                               Page 2.
May 28, 2004


Pooling and Servicing Agreement, the Underwriting Agreement and the Purchase
Agreement are collectively referred to herein as the "Agreements." Capitalized
terms not defined herein have the meanings assigned to them in the Agreements.

         In rendering this opinion letter, as to relevant factual matters we
have examined the documents described above and such other documents as we have
deemed necessary including, where we have deemed appropriate, representations or
certifications of officers of parties thereto or public officials. In rendering
this opinion letter, except for the matters that are specifically addressed in
the opinions expressed below, with your permission we have assumed, and are
relying thereon without independent investigation, (i) the authenticity of all
documents submitted to us as originals or as copies thereof, and the conformity
to the originals of all documents submitted to us as copies, (ii) the necessary
entity formation and continuing existence in the jurisdiction of formation, and
the necessary licensing and qualification in all jurisdictions, of all parties
to all documents, (iii) the necessary authorization, execution, delivery and
enforceability of all documents, and the necessary entity power with respect
thereto, and (iv) that there is not any other agreement that modifies or
supplements the agreements expressed in any document to which this opinion
letter relates and that renders any of the opinions expressed below inconsistent
with such document as so modified or supplemented. In rendering this opinion
letter, except for the matters that are specifically addressed in the opinions
expressed below, we have made no inquiry, have conducted no investigation and
assume no responsibility with respect to (a) the accuracy of and compliance by
the parties thereto with the representations, warranties and covenants as to
factual matters contained in any document or (b) the conformity of the
underlying assets and related documents to the requirements of any agreement to
which this opinion letter relates.

         In rendering this opinion letter, any opinion expressed herein with
respect to the enforceability of any right or obligation is subject to (i)
general principles of equity, including concepts of materiality, reasonableness,
good faith and fair dealing and the possible unavailability of specific
performance and injunctive relief, regardless of whether considered in a
proceeding in equity or at law, (ii) bankruptcy, insolvency, receivership,
reorganization, liquidation, voidable preference, fraudulent conveyance and
transfer, moratorium and other similar laws affecting the rights of creditors or
secured parties, (iii) the effect of certain laws, regulations and judicial and
other decisions upon (a) the availability and enforceability of certain
remedies, including the remedies of specific performance and self-help, and
provisions purporting to waive the obligation of good faith, materiality, fair
dealing, diligence, reasonableness or objection to judicial jurisdiction, venue
or forum and (b) the enforceability of any provision the violation of which
would not have any material adverse effect on the performance by any party of
its obligations under any agreement and (iv) public policy considerations
underlying United States federal securities laws, to the extent that such public
policy considerations limit the enforceability of any provision of any agreement
which purports or is construed to provide indemnification with respect to
securities law violations. However, the non-enforceability of any provisions
referred to in foregoing clause (iii) will not, taken as a whole, materially
interfere with the practical realization of the benefits of the rights and
remedies included in any such agreement which is the subject of any opinion
expressed below, except for the consequences of any judicial, administrative,
procedural or other delay which may be imposed by, relate to or arise from
applicable laws, equitable principles and interpretations thereof.





Impac Secured Assets Corp., Series 2004-2                                Page 3.
May 28, 2004


         This opinion letter is based upon our review of the documents referred
to herein. We have conducted no independent investigation with respect to the
facts contained in such documents and relied upon in rendering this opinion
letter. We also note that we do not represent any of the parties to the
transactions to which this opinion letter relates or any of their affiliates in
connection with matters other than certain transactions. However, the attorneys
in this firm who are directly involved in the representation of parties to the
transactions to which this opinion letter relates have no actual present
knowledge of the inaccuracy of any fact relied upon in rendering this opinion
letter. In addition, if we indicate herein that any opinion is based on our
knowledge, our opinion is based solely on the actual present knowledge of such
attorneys.

         In rendering this opinion letter, we do not express any opinion
concerning any law other than the laws of the State of New York, and the federal
laws of the United States, including without limitation the Securities Act of
1933, as amended (the "1933 Act"). We do not express any opinion herein with
respect to any matter not specifically addressed in the opinions expressed
below, including without limitation (i) any statute, regulation or provision of
law of any county, municipality or other political subdivision or any agency or
instrumentality thereof or (ii) the securities or tax laws of any jurisdiction.

         Based upon and subject to the foregoing, it is our opinion that:

          1.   Each of the Agreements to which the Seller, the Depositor, Master
               Servicer or IMH is a party (to the extent that the laws of the
               State of New York are designated therein as the governing law
               thereof), assuming the necessary authorization, execution and
               delivery thereof by the parties thereto (other than any party as
               to which we opine to that effect herein) and the enforceability
               thereof against the other parties thereto, is a valid and legally
               binding agreement under the laws of the State of New York,
               enforceable thereunder in accordance with its terms against the
               Seller, Depositor, Master Servicer or IMH, as the case may be.

          2.   The issuance, offer, sale and delivery of the Certificates have
               been duly authorized by the Depositor.

          3.   The Certificates, assuming the necessary execution,
               authentication and delivery thereof and payment therefor in
               accordance with the applicable Agreements, are valid and legally
               binding obligations under the laws of the State of New York,
               enforceable thereunder in accordance with their terms against the
               Depositor, and are entitled to the benefits of the Pooling and
               Servicing Agreement.

          4.   With respect to each of the Seller, the Depositor and IMH, the
               performance of its obligations under each of the Agreements to
               which it is a party and the consummation of the transactions
               contemplated thereby do not require any consent, approval,
               authorization or order of, filing with or notice to any United
               States federal or State of New York court, agency or other
               governmental body under any United States federal or State of New
               York statute or regulation that in our experience is





Impac Secured Assets Corp., Series 2004-2                                Page 4.
May 28, 2004


               normally applicable to transactions of the type contemplated by
               the Agreements, except such as may be required under the
               securities laws of any State of the United States or such as have
               been obtained, effected or given.

          5.   With respect to each of the Seller, the Depositor and IMH, the
               performance of its obligations under each of the Agreements to
               which it is a party and the consummation of the transactions
               contemplated thereby will not result in any breach or violation
               of any United States federal or State of New York statute or
               regulation or that in our experience is normally applicable to
               transactions of the type contemplated by the Agreements.

          6.   The Registration Statement has become effective under the 1933
               Act. To our knowledge, no stop order suspending the effectiveness
               of the Registration Statement has been issued and not withdrawn,
               and no proceedings for that purpose have been instituted or
               threatened under Section 8(d) of the 1933 Act.

          7.   The Registration Statement as of the date of the Prospectus
               Supplement and the date hereof, and the Prospectus as of the date
               of the Prospectus Supplement and the date hereof, other than any
               financial and statistical information, Computational Materials
               and ABS Term Sheets contained or incorporated by reference
               therein as to which we express no opinion herein, complied as to
               form in all material respects with the requirements of the 1933
               Act and the applicable rules and regulations thereunder.

          8.   To our knowledge, there are no material contracts, indentures or
               other documents of a character required to be described or
               referred to in either the Registration Statement or the
               Prospectus or to be filed as exhibits to the Registration
               Statement, other than any Computational Materials and ABS Term
               Sheets, as to which we express no opinion herein, and those
               described or referred to therein or filed or incorporated by
               reference as exhibits thereto.

          9.   The statements made in the Prospectus under the heading
               "Description of the Offered Certificates" insofar as such
               statements purport to summarize certain provisions of the
               Certificates and the Pooling and Servicing Agreement, provide a
               fair summary of such provisions. The statements made in the
               Prospectus, under the headings "Legal Aspects of Mortgage Loans--
               Applicability of Usury Laws," and "--Alternative Mortgage
               Instruments" and "ERISA Considerations" to the extent that they
               constitute matters of United States federal or State of New York
               law or legal conclusions with respect thereto, while not
               purporting to discuss all possible consequences of investment in
               the Certificates offered thereby, are correct in all material
               respects with respect to those consequences or matters that are
               discussed therein.





Impac Secured Assets Corp., Series 2004-2                               Page 5.
May 28, 2004

          10.  The Pooling and Servicing Agreement is not required to be
               qualified under the Trust Indenture Act of 1939, as amended. The
               Trust Fund created by the Pooling and Servicing Agreement is not
               an "investment company" within the meaning of the Investment
               Company Act of 1940, as amended.

          11.  The Publicly Offered Certificates (other than the Class M-2
               Certificates and the Class M-3 Certificates) will be "mortgage
               related securities" as defined in Section 3(a)(41) of the
               Securities Exchange Act of 1934, as amended, so long as each such
               class is rated in one of the two highest rating categories by at
               least one "nationally recognized statistical rating organization"
               as that term is used in that Section.

         This opinion letter is rendered for the sole benefit of each addressee
hereof with respect to the matters specifically addressed herein, and no other
person or entity is entitled to rely hereon. Copies of this opinion letter may
not be made available, and this opinion letter may not be quoted or referred to
in any other document made available, to any other person or entity except (i)
to any applicable rating agency, institution providing credit enhancement or
liquidity support or governmental authority, (ii) to any accountant or attorney
for any person or entity entitled hereunder to rely hereon or to whom or which
this opinion letter may be made available as provided herein and (iii) as
otherwise required by law; provided that none of the foregoing is entitled to
rely hereon unless an addressee hereof. We assume no obligation to revise,
supplement or withdraw this opinion letter, or otherwise inform any addressee
hereof or other person or entity, with respect to any change occurring
subsequent to the delivery hereof in any applicable fact or law or any judicial
or administrative interpretation thereof, even though such change may affect a
legal analysis or conclusion contained herein. In addition, no attorney-client
relationship exists or has existed by reason of this opinion letter between our
firm and any addressee hereof or other person or entity except for any addressee
that is identified in the first paragraph hereof as a person or entity for which
we have acted as counsel in rendering this opinion letter. In permitting
reliance hereon by any person or entity other than such an addressee for which
we have acted as counsel, we are not acting as counsel for such other person or
entity and have not assumed and are not assuming any responsibility to advise
such other person or entity with respect to the adequacy of this opinion letter
for its purposes.

                                                Very truly yours,


                                                /s/ Thacher Proffitt & Wood LLP