<PAGE>   1

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 20549

                                    FORM 10-Q


[X]  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
     EXCHANGE ACT OF 1934 FOR THE QUARTERLY PERIOD ENDED SEPTEMBER 30, 2000

                                       OR

[ ]  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
     EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM ________ TO ________


                         Commission file number 0-18169

                            IEA INCOME FUND IX, L.P.
             (Exact name of registrant as specified in its charter)


               California                                      94-3069954
    (State or other jurisdiction of                          (I.R.S. Employer
     incorporation or organization)                         Identification No.)



         One Front Street, 15th Floor, San Francisco, California 94111
              (Address of principal executive offices) (Zip Code)

                                 (415) 677-8990
              (Registrant's telephone number, including area code)


Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days. Yes [X]. No [ ].


<PAGE>   2


                            IEA INCOME FUND IX, L.P.

                  REPORT ON FORM 10-Q FOR THE QUARTERLY PERIOD
                            ENDED SEPTEMBER 30, 2000

                                TABLE OF CONTENTS


<TABLE>
<CAPTION>
                                                                                                    PAGE
<S>                                                                                                 <C>
PART I - FINANCIAL INFORMATION

 Item 1. Financial Statements


         Condensed Balance Sheets (unaudited) - September 30, 2000 and December 31, 1999              4


         Condensed Statements of Operations (unaudited) for the three and nine months ended
         September 30, 2000 and 1999                                                                  5


         Condensed Statements of Cash Flows (unaudited) for the nine months ended September 30,
         2000 and 1999                                                                                6


         Notes to Condensed Financial Statements (unaudited)                                          7


 Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations       10


 Item 3. Quantitative and Qualitative Disclosures About Market Risk                                  11


PART II - OTHER INFORMATION


 Item 1. Legal Proceedings                                                                           12


 Item 6. Exhibits and Reports on Form 8-K                                                            13
</TABLE>



                                       2
<PAGE>   3

                         PART I - FINANCIAL INFORMATION


Item 1. Financial Statements

        Presented herein are the Registrant's condensed balance sheets as of
        September 30, 2000 and December 31, 1999, condensed statements of
        operations for the three and nine months ended September 30, 2000 and
        1999, and condensed statements of cash flows for the nine months ended
        September 30, 2000 and 1999.





                                       3
<PAGE>   4

                            IEA INCOME FUND IX, L.P.

                            CONDENSED BALANCE SHEETS

                                   (UNAUDITED)



<TABLE>
<CAPTION>
                                                                             September 30,       December 31,
                                                                                 2000                1999
                                                                             -------------       -------------
<S>                                                                          <C>                 <C>
                 Assets

Current assets:
   Cash and cash equivalents, includes $665,896 at September 30, 2000
      and $492,580 at December 31, 1999 in interest-bearing accounts         $    667,774         $    492,680
   Net lease receivables due from Leasing Company
      (Notes 1 and 2)                                                             115,513              184,713
                                                                             ------------         ------------

         Total current assets                                                     783,287              677,393
                                                                             ------------         ------------

Container rental equipment, at cost                                            11,233,876           12,927,344
   Less accumulated depreciation                                                6,994,636            7,529,966
                                                                             ------------         ------------
      Net container rental equipment                                            4,239,240            5,397,378
                                                                             ------------         ------------

         Total assets                                                        $  5,022,527         $  6,074,771
                                                                             ============         ============

            Partners' Capital

Partners' capital (deficit):
   General partner                                                           $    (66,629)        $    (56,106)
   Limited partners                                                             5,089,156            6,130,877
                                                                             ------------         ------------

         Total partners' capital                                             $  5,022,527         $  6,074,771
                                                                             ============         ============
</TABLE>



        The accompanying notes are an integral part of these condensed financial
statements.


                                       4
<PAGE>   5

                            IEA INCOME FUND IX, L.P.

                       CONDENSED STATEMENTS OF OPERATIONS

                                   (UNAUDITED)


<TABLE>
<CAPTION>
                                                                  Three Months Ended                  Nine Months Ended
                                                            ------------------------------     -------------------------------
                                                            September 30,    September 30,     September 30,     September 30,
                                                                2000              1999              2000              1999
                                                            -------------    -------------     -------------     -------------
<S>                                                         <C>              <C>               <C>               <C>
Net lease revenue (Notes 1 and 3)                            $ 269,581         $ 287,550         $ 720,181         $ 886,342

Other operating expenses:
  Depreciation                                                 166,983           193,834           527,418           605,292
  Other general and administrative expenses                     14,594             9,338            45,850            31,618
                                                             ---------         ---------         ---------         ---------
                                                               181,577           203,172           573,268           636,910
                                                             ---------         ---------         ---------         ---------

    Income from operations                                      88,004            84,378           146,913           249,432

Other income (loss):
  Interest income                                                6,033             6,936            19,033            22,734
  Net loss on disposal of equipment                            (42,805)         (105,519)         (114,935)         (172,479)
                                                             ---------         ---------         ---------         ---------
                                                               (36,772)          (98,583)          (95,902)         (149,745)
                                                             ---------         ---------         ---------         ---------

    Net income (loss)                                        $  51,232         $ (14,205)        $  51,011         $  99,687
                                                             =========         =========         =========         =========

Allocation of net income (loss):
  General partner                                            $   9,457         $  11,934         $  30,476         $  45,276
  Limited partners                                              41,775           (26,139)           20,535            54,411
                                                             ---------         ---------         ---------         ---------

                                                             $  51,232         $ (14,205)        $  51,011         $  99,687
                                                             =========         =========         =========         =========


Limited partners' per unit share of net income (loss)        $    1.22         $   (0.77)        $    0.60         $    1.60
                                                             =========         =========         =========         =========
</TABLE>


        The accompanying notes are an integral part of these condensed financial
statements.


                                       5
<PAGE>   6

                                      IEA INCOME FUND IX, L.P.

                                 CONDENSED STATEMENTS OF CASH FLOWS

                                            (UNAUDITED)


<TABLE>
<CAPTION>
                                                                   Nine Months Ended
                                                            ---------------------------------
                                                            September 30,       September 30,
                                                                2000                1999
                                                            -------------       -------------
<S>                                                         <C>                 <C>
Net cash provided by operating activities                   $   874,228         $   985,104

Cash provided by investing activities:
  Proceeds from sale of container rental equipment              404,121             379,906

Cash used in financing activities:
  Distribution to Partners                                   (1,103,255)         (1,471,798)
                                                            -----------         -----------


Net increase (decrease) in cash and cash equivalents            175,094            (106,788)


Cash and cash equivalents, beginning of period                  492,680             780,429
                                                            -----------         -----------

Cash and cash equivalents, end of period                    $   667,774         $   673,641
                                                            ===========         ===========
</TABLE>



        The accompanying notes are an integral part of these condensed financial
statements.


                                       6
<PAGE>   7

                            IEA INCOME FUND IX, L.P.

               NOTES TO CONDENSED FINANCIAL STATEMENTS (UNAUDITED)


(1) Summary of Significant Accounting Policies

    (a) Nature of Operations

        IEA Income Fund IX, L.P. (the "Partnership") is a limited partnership
        organized under the laws of the State of California on June 8, 1988 for
        the purpose of owning and leasing marine cargo containers worldwide to
        ocean carriers. To this extent, the Partnership's operations are subject
        to the fluctuations of world economic and political conditions. Such
        factors may affect the pattern and levels of world trade. The
        Partnership believes that the profitability of, and risks associated
        with, leases to foreign customers is generally the same as those of
        leases to domestic customers. The Partnership's leases generally require
        all payments to be made in United States currency.

        Cronos Capital Corp. ("CCC") is the general partner and, with its
        affiliate Cronos Containers Limited (the "Leasing Company"), manages the
        business of the Partnership. CCC and the Leasing Company also manage the
        container leasing business for other partnerships affiliated with the
        general partner. The Partnership shall continue until December 31, 2009,
        unless sooner terminated upon the occurrence of certain events.

        The Partnership commenced operations on December 5, 1988, when the
        minimum subscription proceeds of $1,000,000 were obtained. The
        Partnership offered 40,000 units of limited partnership interest at $500
        per unit, or $20,000,000. The offering terminated on September 11, 1989,
        at which time 33,992 limited partnership units had been purchased.

    (b) Leasing Company and Leasing Agent Agreement

        Pursuant to the Limited Partnership Agreement of the Partnership, all
        authority to administer the business of the Partnership is vested in
        CCC. CCC has entered into a Leasing Agent Agreement whereby the Leasing
        Company has the responsibility to manage the leasing operations of all
        equipment owned by the Partnership. Pursuant to the Agreement, the
        Leasing Company is responsible for leasing, managing and re-leasing the
        Partnership's containers to ocean carriers, and has full discretion over
        which ocean carriers and suppliers of goods and services it may deal
        with. The Leasing Agent Agreement permits the Leasing Company to use the
        containers owned by the Partnership, together with other containers
        owned or managed by the Leasing Company and its affiliates, as part of a
        single fleet operated without regard to ownership. Since the Leasing
        Agent Agreement meets the definition of an operating lease in Statement
        of Financial Accounting Standards (SFAS) No. 13, it is accounted for as
        a lease under which the Partnership is lessor and the Leasing Company is
        lessee.

        The Leasing Agent Agreement generally provides that the Leasing Company
        will make payments to the Partnership based upon rentals collected from
        ocean carriers after deducting direct operating expenses and management
        fees to CCC. The Leasing Company leases containers to ocean carriers,
        generally under operating leases which are either master leases or term
        leases (mostly one to five years). Master leases do not specify the
        exact number of containers to be leased or the term that each container
        will remain on hire but allow the ocean carrier to pick up and drop off
        containers at various locations; rentals are based upon the number of
        containers used and the applicable per-diem rate. Accordingly, rentals
        under master leases are all variable and contingent upon the number of
        containers used. Most containers are leased to ocean carriers under
        master leases; leasing agreements with fixed payment terms are not
        material to the financial statements. Since there are no material
        minimum lease rentals, no disclosure of minimum lease rentals is
        provided in these condensed financial statements.



                                                                     (Continued)
                                       7
<PAGE>   8

                            IEA INCOME FUND IX, L.P.

               NOTES TO CONDENSED FINANCIAL STATEMENTS (UNAUDITED)


    (c) Basis of Accounting

        The Partnership utilizes the accrual method of accounting. Net lease
        revenue is recorded by the Partnership in each period based upon its
        leasing agent agreement with the Leasing Company. Net lease revenue is
        generally dependent upon operating lease rentals from operating lease
        agreements between the Leasing Company and its various lessees, less
        direct operating expenses and management fees due in respect of the
        containers specified in each operating lease agreement.

    (d) Financial Statement Presentation

        These condensed financial statements have been prepared without audit.
        Certain information and footnote disclosures normally included in
        financial statements prepared in accordance with accounting principles
        generally accepted in The United States of America ("GAAP") have been
        omitted. It is suggested that these condensed financial statements be
        read in conjunction with the financial statements and accompanying notes
        in the Partnership's latest annual report on Form 10-K.

        The preparation of financial statements in conformity with GAAP requires
        the Partnership to make estimates and assumptions that affect the
        reported amounts of assets and liabilities and disclosure of contingent
        assets and liabilities at the date of the financial statements and the
        reported amounts of revenues and expenses during the reported period.
        Actual results could differ from those estimates.

        The interim financial statements presented herewith reflect all
        adjustments of a normal recurring nature which are, in the opinion of
        management, necessary to a fair statement of the financial condition and
        results of operations for the interim periods presented. The results of
        operations for such interim periods are not necessarily indicative of
        the results to be expected for the full year.


(2) Net Lease Receivables Due from Leasing Company

    Net lease receivables due from the Leasing Company are determined by
    deducting direct operating payables and accrued expenses, base management
    fees payable, and reimbursed administrative expenses payable to CCC and its
    affiliates from the rental billings payable by the Leasing Company to the
    Partnership under operating leases to ocean carriers for the containers
    owned by the Partnership. Net lease receivables at September 30, 2000 and
    December 31, 1999 were as follows:

<TABLE>
<CAPTION>
                                                            September 30,    December 31,
                                                                2000            1999
                                                            -------------    ------------
<S>                                                         <C>              <C>
        Gross lease receivables                               $520,899        $526,631
        Less:
        Direct operating payables and accrued expenses         194,695         164,098
        Damage protection reserve                               35,998          44,497
        Base management fees payable                            54,267          58,250
        Reimbursed administrative expenses                      18,204           6,673
        Allowance for doubtful accounts                        102,222          68,400
                                                              --------        --------

        Net lease receivables                                 $115,513        $184,713
                                                              ========        ========
</TABLE>



                                                                     (Continued)
                                       8
<PAGE>   9

                            IEA INCOME FUND IX, L.P.

               NOTES TO CONDENSED FINANCIAL STATEMENTS (UNAUDITED)


(3) Net Lease Revenue

    Net lease revenue is determined by deducting direct operating expenses, base
    management fees and reimbursed administrative expenses to CCC from the
    rental revenue billed by the Leasing Company under operating leases to ocean
    carriers for the containers owned by the Partnership. Net lease revenue for
    the three and nine-month periods ended September 30, 2000 and 1999 was as
    follows:

<TABLE>
<CAPTION>
                                                        Three Months Ended                 Nine Months Ended
                                                  -------------------------------    --------------------------------
                                                  September 30,     September 30,    September 30,      September 30,
                                                      2000              1999              2000              1999
                                                  -------------     -------------    -------------      -------------
<S>                                               <C>               <C>              <C>               <C>
        Rental revenue                             $  360,147        $  415,184        $1,121,431        $1,322,474
        Less:
        Rental equipment operating expenses            55,340            80,286           266,284           270,348
        Base management fees                           24,827            29,626            73,676            99,586
        Reimbursed administrative expenses             10,399            17,722            61,290            66,198
                                                   ----------        ----------        ----------        ----------

                                                   $  269,581        $  287,550        $  720,181        $  886,342
                                                   ==========        ==========        ==========        ==========
</TABLE>


(4) Operating Segment

    The Financial Accounting Standards Board has issued SFAS No. 131,
    "Disclosures about Segments of an Enterprise and Related Information," which
    changes the way public business enterprises report financial and descriptive
    information about reportable operating segments. An operating segment is a
    component of an enterprise that engages in business activities from which it
    may earn revenues and incur expenses, whose operating results are regularly
    reviewed by the enterprise's chief operating decision maker to make
    decisions about resources to be allocated to the segment and assess its
    performance, and about which separate financial information is available.
    Management operates the Partnership's container fleet as a homogenous unit
    and has determined, after considering the requirements of SFAS No. 131, that
    as such it has a single reportable operating segment.

    The Partnership derives its revenues from dry cargo marine containers. As of
    September 30, 2000, the Partnership operated 1,491 twenty-foot, 541
    forty-foot and 1,971 forty-foot high-cube dry cargo marine containers.

    Due to the Partnership's lack of information regarding the physical location
    of its fleet of containers when on lease in the global shipping trade, it is
    impracticable to provide the geographic area information required by SFAS
    No. 131.

                                     ******



                                       9
<PAGE>   10

Item 2. Management's Discussion and Analysis of Financial Condition and Results
of Operations

It is suggested that the following discussion be read in conjunction with the
Registrant's most recent annual report on Form 10-K.


1)  Material changes in financial condition between September 30, 2000 and
    December 31, 1999.

    During the first nine months of 2000, the Registrant disposed of 460
    containers as part of its ongoing container operations. At September 30,
    2000, 63% of the original equipment remained in the Registrant's fleet, as
    compared to 72% at December 31, 1999, and was comprised of the following:

<TABLE>
<CAPTION>
                                                                   40-Foot
                                         20-Foot      40-Foot     High-Cube
                                         -------      -------     ---------
<S>                                      <C>          <C>         <C>
        Containers on lease:
             Term leases                    134           94          189
             Master leases                1,071          338          618
                                          -----        -----        -----
                Subtotal                  1,205          432          807

        Containers off lease                286          109          164
                                          -----        -----        -----

             Total container fleet        1,491          541          971
                                          =====        =====        =====
</TABLE>


<TABLE>
<CAPTION>
                                                                                                      40-Foot
                                                        20-Foot                40-Foot               High-Cube
                                                   ----------------       ----------------       ----------------
                                                   Units        %         Units        %         Units        %
                                                   -----      -----       -----      -----       -----      -----
<S>                                                <C>        <C>         <C>        <C>         <C>        <C>
        Total purchases                            2,327        100%        799        100%      1,653        100%
             Less disposals                          836         36%        258         32%        682         41%
                                                   -----      -----       -----      -----       -----      -----

        Remaining fleet at September 30, 2000      1,491         64%        541         68%        971         59%
                                                   =====      =====       =====      =====       =====      =====
</TABLE>


    The Registrant disposed of 106 twenty-foot and 24 forty-foot dry cargo
    marine containers, as well as 56 forty-foot high cube dry cargo marine
    container during the third quarter of 2000, as compared to 102 twenty-foot
    and 17 forty-foot dry cargo marine containers, as well as 15 forty-foot high
    cube dry cargo marine containers during the same period in the prior year.
    These disposals resulted in a loss of $114,935 for the third quarter of
    2000, as compared to a loss of $172,479 for the same period in the prior
    year. The Registrant does not believe that the carrying amount of its
    containers has been permanently impaired or that events or changes in
    circumstances have indicated that the carrying amount of its containers may
    not be fully recoverable. The Registrant believes that the loss on container
    disposals was a result of various factors including the age, condition,
    suitability for continued leasing, as well as the geographical location of
    the containers when disposed. These factors will continue to influence the
    amount of sales proceeds received and the related gain or loss on container
    disposals, which may fluctuate in subsequent periods.

    The Registrant's allowance for doubtful accounts increased from $68,400 at
    December 31, 1999 to $102,222 at September 30, 2000. This increase was
    attributable to the delinquent account receivable balances of approximately
    17 lessees. The Leasing Company has either negotiated specific payment terms
    with these lessees or is pursuing other alternatives to collect the
    outstanding balances. In each instance, the Registrant believes it has
    recorded appropriate allowance.

    During the third quarter of 2000, distributions issued from operations and
    sales proceeds amounted to $384,581, reflecting distributions due to the
    general and limited partners for the second quarter of 2000. This represents
    a decrease from the $398,021 issued during the second quarter of 2000,
    reflecting distributions due for the first quarter of 2000. The Registrant's
    continuing disposal of containers should produce lower operating results
    and, consequently, lower distributions to its partners in subsequent
    periods. Sales proceeds distributed to its partners may fluctuate in
    subsequent periods, reflecting the level of container disposals.



                                                                     (Continued)
                                       10
<PAGE>   11

    During the third quarter of 2000, growth in the volume of containerized
    trade continued to improve. As a result, demand for leased equipment
    strengthened in many locations, but most significantly throughout Asia. With
    the growth in the volume of world trade, ocean carriers are committing their
    capital to the purchase of additional containerships and turning to leasing
    companies to supply them with the containers they need to meet their growing
    freight requirements. The container leasing market has rebounded and
    prospects have somewhat improved, but lease rates have remained at generally
    the same low level as at the beginning of this year. At the same time,
    inventories of idle equipment have been reduced in Europe, but there has
    been no appreciable reduction in the U.S. The strong U.S. economy continued
    to import more than it exported. This imbalance has had the effect of
    further increasing idle container inventories, particularly on the U.S. East
    Coast.

2)  Material changes in the results of operations between the three and
    nine-month periods ended September 30, 2000 and the three and nine-month
    periods ended September 30, 1999.

    Net lease revenue for the three and nine-month periods ended September 30,
    2000 was $269,581 and $720,181, respectively, a decline of approximately 6%
    and 19% from the same three and nine-month periods in the prior year. Gross
    rental revenue (a component of net lease revenue) for the three and
    nine-month periods ended September 30, 2000 was $360,147 and $1,121,431,
    respectively, a decline of 13% and 15% from the same three and nine-month
    periods in 1999. Gross rental revenue was primarily impacted by a smaller
    fleet size and lower per-diem rental rates. Average per-diem rental rates
    for the three and nine-month periods ended September 30, 2000 declined 4%
    and 10%, respectively, when compared to the same three and nine-month
    periods in the prior year. The Registrant's average fleet size and
    utilization rates for the three and nine-month periods ended September 30,
    2000 and 1999 were as follows:

<TABLE>
<CAPTION>
                                                     Three Months Ended           Nine Months Ended
                                                ----------------------------  ---------------------------
                                                September 30,  September 30,  September 30, September 30,
                                                     2000          1999          2000           1999
                                                -------------  -------------  ------------- -------------
<S>                                             <C>            <C>            <C>           <C>
        Average fleet size (measured in
         twenty-foot equivalent units (TEU))        4,599         5,366         4,875          5,541

        Average Utilization                            82%           78%           81%            78%
</TABLE>

    The Registrant's declining fleet size contributed to a decline of 14% and
    13%, respectively, in depreciation expense when compared to the same three
    and nine-month periods in the prior year. Rental equipment operating
    expenses were 15% and 24%, respectively, of the Registrant's gross lease
    revenue during the three and nine-month periods ended September 30, 2000, as
    compared to 19% and 20%, respectively, during the three and nine-month
    periods ended September 30, 1999. The large decrease for the three-month
    period ended September 30, 2000 was attributable to the recovery of doubtful
    accounts.


Item 3. Quantitative and Qualitative Disclosures About Market Risk

        Not applicable.



                                       11
<PAGE>   12

                           PART II - OTHER INFORMATION


Item 1. Legal Proceedings

On March 20, 2000, KM Investments, LLC, a California limited liability company
("KM") filed its complaint (the "Complaint") in the Superior Court for the
County of Los Angeles against CCC, as general partner of the Partnership,
alleging violation of the California Revised Limited Partnership Act, breach of
fiduciary duty, and unfair competition. KM claims to be an assignee of units of
limited partnership interests in the Partnership and six other California
limited partnerships (collectively, the "Cronos Partnerships") managed by CCC as
general partner. KM, which is in the business of making unregistered tender
offers for up to 4.9% of the outstanding interests in limited partnerships,
claims that CCC has wrongfully refused to provide KM with lists of the limited
partners of the Cronos Partnerships to enable KM to make unregistered tender
offers to the limited partners of the Cronos Partnerships.

KM asks for declaratory relief, damages according to proof, attorneys' fees,
costs, interest, a temporary restraining order and/or a preliminary injunction
barring CCC from giving limited partner lists to any other party before
delivering such lists to KM, punitive damages, and an order prohibiting CCC from
receiving reimbursement of its legal fees incurred in defending the action from
the Cronos Partnerships.

On April 24, 2000, CCC filed its demurrer to the Complaint and its motion to
strike those portions of the Complaint seeking punitive damages. By its
demurrer, CCC asserted that KM, as an assignee of units of the Cronos
Partnerships, is not entitled to review or receive a copy of the lists of the
limited partners of the Cronos Partnerships; that CCC has not breached any
fiduciary duty to KM; and that CCC has not engaged in unfair competition as
alleged by KM. CCC requested that the Court dismiss KM's Complaint.

On June 8, 2000, the Court heard CCC's demurrer, and sustained (i.e., granted)
it in its entirety, allowing KM thirty days to file an amended complaint. KM did
so on or about July 10, 2000, asserting the same causes of action as set forth
in its original complaint. On August 25, 2000, CCC filed its demurrer to KM's
First Amended Complaint and its motion to strike those portions of the First
Amended Complaint seeking punitive damages. On October 11, 2000, the Court heard
CCC's motions. It sustained CCC's demurrer to KM's fourth cause of action
seeking declaratory relief, but overruled (i.e., denied) CCC's demurrer to KM's
first three causes of action, on the ground that the evidence submitted by CCC
was not properly before the Court on CCC's demurrer to KM's First Amended
Complaint. At the same time, the Court granted CCC's motion to strike those
portions of KM's First Amended Complaint seeking punitive damages.

On October 20, 2000, CCC filed its answer to KM's First Amended Complaint,
denying the allegations thereof, denying that plaintiff is entitled to any
damages, and asserting various affirmative defenses. CCC believes that KM does
not have standing to inspect or receive lists of the limited partners of the
limited partnerships managed by CCC, and that CCC has meritorious defenses to
KM's First Amended Complaint.



                                       12
<PAGE>   13

                       PART II - OTHER INFORMATION (CONT.)


Item 6. Exhibits and Reports on Form 8-K

(a) Exhibits

<TABLE>
<CAPTION>
           Exhibit
              No.                       Description                            Method of Filing
           -------                      -----------                            ----------------
<S>                    <C>                                                     <C>
             3(a)      Limited Partnership Agreement of the Registrant,        *
                       amended and restated as of September 12, 1988

             3(b)      Certificate of Limited Partnership of the               **
                       Registrant

             27        Financial Data Schedule                                 Filed with this
                                                                               document
</TABLE>


(b) Reports on Form 8-K

    No reports on Form 8-K were filed by the Registrant during the quarter ended
    September 30, 2000.


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

*   Incorporated by reference to Exhibit "A" to the Prospectus of the Registrant
    dated September 12, 1988, included as part of Registration Statement on Form
    S-1 (No. 33-23321)

**  Incorporated by reference to Exhibit 3.4 to the Registration Statement on
    Form S-1 (No. 33-23321)




                                       13
<PAGE>   14

                                   SIGNATURES



        Pursuant to the requirements of the Securities Exchange Act of 1934, the
Registrant has duly caused this Report to be signed on its behalf by the
undersigned thereunto duly authorized.




                                          IEA INCOME FUND IX, L.P.


                                          By  Cronos Capital Corp.
                                              The General Partner




                                          By  /s/ Dennis J. Tietz
                                              ----------------------------------
                                              Dennis J. Tietz
                                              President and Director of Cronos
                                              Capital Corp. ("CCC")
                                              Principal Executive Officer of CCC




Date: November 14, 2000





                                       14
<PAGE>   15

                                  EXHIBIT INDEX


<TABLE>
<CAPTION>
           Exhibit
              No.                       Description                            Method of Filing
           -------                      -----------                            ----------------
<S>                    <C>                                                     <C>
             3(a)      Limited Partnership Agreement of the Registrant,        *
                       amended and restated as of September 12, 1988

             3(b)      Certificate of Limited Partnership of the               **
                       Registrant

             27        Financial Data Schedule                                 Filed with this
                                                                               document
</TABLE>





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

*   Incorporated by reference to Exhibit "A" to the Prospectus of the Registrant
    dated September 12, 1988, included as part of Registration Statement on Form
    S-1 (No. 33-23321)

**  Incorporated by reference to Exhibit 3.4 to the Registration Statement on
    Form S-1 (No. 33-23321)