<PAGE>

                                    FORM 10-Q



                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549


            [ X ] QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF
                       THE SECURITIES EXCHANGE ACT OF 1934

                  For the quarterly period ended March 31, 1999

                                       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 0-18359


          SWIFT ENERGY MANAGED PENSION ASSETS PARTNERSHIP 1989-B, LTD.
             (Exact name of registrant as specified in its charter)

<TABLE>
<S>                                           <C>
                  Texas                                   76-0282457
(State or other jurisdiction of organization) (I.R.S. Employer Identification No.)
</TABLE>


                        16825 Northchase Drive, Suite 400
                              Houston, Texas 77060
                    (Address of principal executive offices)
                                   (Zip Code)

                                  (281)874-2700
              (Registrant's telephone number, including area code)

                                      None
              (Former name, former address and former fiscal year,
                          if changed since last report)


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>

          SWIFT ENERGY MANAGED PENSION ASSETS PARTNERSHIP 1989-B, LTD.

                                      INDEX



<TABLE>
<CAPTION>
PART I.    FINANCIAL INFORMATION                                        PAGE
      <S>                                                                <C>
      ITEM 1.    Financial Statements

            Balance Sheets

                - March 31, 1999 and December 31, 1998                    3

            Statements of Operations

                - Three month periods ended March 31, 1999 and 1998       4

            Statements of Cash Flows

                - Three month periods ended March 31, 1999 and 1998       5

            Notes to Financial Statements                                 6

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

PART II.    OTHER INFORMATION                                            11


SIGNATURES                                                               12
</TABLE>


<PAGE>

          SWIFT ENERGY MANAGED PENSION ASSETS PARTNERSHIP 1989-B, LTD.
                                 BALANCE SHEETS



<TABLE>
<CAPTION>
                                                                                          March 31,           December 31,
                                                                                            1999                  1998
                                                                                       --------------       --------------
                                                                                         (Unaudited)
         <S>                                                                           <C>                  <C>
         ASSETS:

         Current Assets:
              Cash and cash equivalents                                                $        1,536       $        1,530 
              Nonoperating interests income receivable                                         56,239               56,576 
                                                                                       ---------------      ---------------
                  Total Current Assets                                                         57,775               58,106 
                                                                                       ---------------      ---------------
         Nonoperating interests in oil and gas
              properties, using full cost accounting                                        3,804,788            3,900,701 
         Less-Accumulated amortization                                                     (3,048,771)          (2,998,631)
                                                                                       ---------------      ---------------
                                                                                              756,017              902,070 
                                                                                       ---------------      ---------------
                                                                                       $      813,792       $      960,176 
                                                                                       ===============      ===============

         LIABILITIES AND PARTNERS' CAPITAL:

         Current Liabilities:
              Accounts Payable                                                         $       63,287       $      197,225 
                                                                                       ---------------      ---------------

         Limited Partners' Capital (39,830.64 Limited Partnership Units;
                                   $100 per unit)                                             734,155              755,567 
         General Partners' Capital                                                             16,350                7,384 
                                                                                       ---------------      ---------------
                  Total Partners' Capital                                                     750,505              762,951 
                                                                                       ---------------      ---------------
                                                                                       $      813,792       $      960,176 
                                                                                       ===============      ===============
</TABLE>

                 See accompanying notes to financial statements.

                                        3


<PAGE>

          SWIFT ENERGY MANAGED PENSION ASSETS PARTNERSHIP 1989-B, LTD.
                            STATEMENTS OF OPERATIONS
                                   (Unaudited)



<TABLE>
<CAPTION>

                                                                                         Three Months Ended
                                                                                              March 31,
                                                                                 ---------------------------------
                                                                                      1999               1998
                                                                                 --------------    ---------------
         <S>                                                                     <C>               <C>
         REVENUES:
             Income from nonoperating interests                                  $        91,562   $        79,974 
             Interest income                                                                  73               258 
                                                                                 ---------------   --------------- 
                                                                                          91,635            80,232 
                                                                                 ---------------   --------------- 
         COSTS AND EXPENSES:
             Amortization                                                                 50,140            49,410 
             General and administrative                                                   22,860            16,212 
                                                                                 ---------------   --------------- 
                                                                                          73,000            65,622 
                                                                                 ---------------   --------------- 
         NET INCOME (LOSS)                                                       $        18,635   $        14,610 
                                                                                 ===============   =============== 
</TABLE>

         Limited Partners' net income (loss)
             per unit

         March 31, 1999                       $           .21 
                                                 ============ 
         March 31, 1998                       $           .37 
                                                 ============ 

                 See accompanying note to financial statements.

                                        4


<PAGE>

          SWIFT ENERGY MANAGED PENSION ASSETS PARTNERSHIP 1989-B, LTD.
                            STATEMENTS OF CASH FLOWS
                                   (Unaudited)


<TABLE>
<CAPTION>
                                                                                          Three Months Ended
                                                                                                March 31,
                                                                                ---------------------------------------
                                                                                       1999                  1998
                                                                                ----------------        ---------------
<S>                                                                             <C>                     <C>
CASH FLOWS FROM OPERATING ACTIVITIES:
    Income (loss)                                                               $         18,635        $        14,610 
    Adjustments to reconcile income (loss) to
      net cash provided by operations:
      Amortization                                                                        50,140                 49,410 
      Change in assets and liabilities:
        (Increase) decrease in nonoperating interests income receivable                      337                 54,253 
        Increase (decrease) in accounts payable                                         (133,938)                    25 
                                                                                  --------------         -------------- 
               Net cash provided by (used in) operating activities                       (64,826)               118,298 
                                                                                  --------------         -------------- 
CASH FLOWS FROM INVESTING ACTIVITIES:
        Additions to nonoperating interests in oil and gas properties                     (1,803)               (27,089)
        Proceeds from sale of nonoperating interests in oil and gas properties            97,716                     -- 
                                                                                  --------------         -------------- 
               Net cash provided by (used in) investing activities                        95,913                (27,089)
                                                                                  --------------         -------------- 
CASH FLOWS FROM FINANCING ACTIVITIES:
      Cash distributions to partners                                                     (31,081)              (157,594)
                                                                                  --------------         -------------- 
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS                                           6                (66,385)
                                                                                  --------------         -------------- 
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD                                           1,530                 67,645 
                                                                                  --------------         -------------- 
CASH AND CASH EQUIVALENTS AT END OF PERIOD                                      $          1,536        $         1,260 
                                                                                  ==============         ==============
</TABLE>


                 See accompanying notes to financial statements.

                                        5


<PAGE>

          SWIFT ENERGY MANAGED PENSION ASSETS PARTNERSHIP 1989-B, LTD.
                          NOTES TO FINANCIAL STATEMENTS
                                   (UNAUDITED)

(1)  General Information -

                  The financial statements included herein have been prepared by
        the  Partnership  and are  unaudited  except  for the  balance  sheet at
        December  31,  1998  which has been  taken  from the  audited  financial
        statements at that date. The financial  statements reflect  adjustments,
        all of which were of a normal recurring nature, which are in the opinion
        of the  managing  general  partner  necessary  for a fair  presentation.
        Certain  information  and  footnote  disclosures  normally  included  in
        financial  statements  prepared in accordance  with  generally  accepted
        accounting  principles  have  been  omitted  pursuant  to the  rules and
        regulations  of the  Securities  and Exchange  Commission  ("SEC").  The
        Partnership  believes adequate disclosure is provided by the information
        presented.  The financial  statements should be read in conjunction with
        the audited  financial  statements  and the notes included in the latest
        Form 10-K.

(2)  Organization and Terms of Partnership Agreement -

                  Swift Energy Managed Pension Assets Partnership 1989-B,  Ltd.,
        a Texas limited partnership ("the  Partnership"),  was formed on May 31,
        1989,  for the purpose of purchasing net profits  interests,  overriding
        royalty  interests and royalty  interests  (collectively,  "nonoperating
        interests") in producing oil and gas properties  within the  continental
        United States. Swift Energy Company ("Swift"), a Texas corporation,  and
        VJM Corporation  ("VJM"),  a California  corporation,  serve as Managing
        General  Partner  and  Special  General  Partner  of  the   Partnership,
        respectively.  The general  partners  are required to  contribute  up to
        1/99th of limited partner net  contributions.  The 480 limited  partners
        made total capital contributions of $3,983,064.

                  Nonoperating  interests  acquisition  costs and the management
        fee are borne 99 percent by the limited  partners and one percent by the
        general  partners.  Organization and syndication costs were borne solely
        by the limited partners.

                  Generally,  all continuing costs (including development costs,
        operating costs,  general and  administrative  reimbursements and direct
        expenses) and revenues are allocated 90 percent to the limited  partners
        and ten percent to the general partners. If prior to partnership payout,
        however,  the cash  distribution  rate for a  certain  period  equals or
        exceeds  17.5  percent,  then for the  following  calendar  year,  these
        continuing  costs and  revenues  will be  allocated  85  percent  to the
        limited  partners  and  15  percent  to  the  general  partners.   After
        partnership  payout,  continuing  costs and  revenues  will be shared 85
        percent by the limited partners, and 15 percent by the general partners,
        even if the cash  distribution  rate is less than 17.5  percent.  During
        1992 and 1991, the cash distribution rate (as defined in the Partnership
        Agreement)  exceeded  17.5  percent  and  thus,  in 1993 and  1992,  the
        continuing  costs and  revenues  were  shared 85 percent by the  limited
        partners  and 15 percent by the general  partners.  During  1997,  1996,
        1995, 1994 and 1993, the cash  distribution rate fell below 17.5 percent
        and thus, in 1997, 1996, 1995 and 1994 the continuing costs and revenues
        were  shared 85 percent by the  limited  partners  and 15 percent by the
        general partners.  Payout occurred in January, 1998; therefore, for 1998
        and each year remaining in the life of the  partnership,  the continuing
        costs and revenues will be shared 85 percent by the limited partners and
        15 percent by the general partners.

(3)  Significant Accounting Policies -

       Use of Estimates -

                  The  preparation  of financial  statements in conformity  with
        generally accepted  accounting  principles  requires  management to make
        estimates and assumptions that affect the reported amounts of assets and
        liabilities  at the date of the  financial  statements  and the reported
        amounts of revenues and expenses  during the  reporting  period.  Actual
        results could differ from estimates. 

                                       6


<PAGE>

          SWIFT ENERGY MANAGED PENSION ASSETS PARTNERSHIP 1989-B, LTD.
                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)
                                   (UNAUDITED)


     Nonoperating Interests in Oil and Gas Properties --

                  The Partnership accounts for its ownership interest in oil and
        gas properties using the proportionate consolidation method, whereby the
        Partnership's  share of assets,  liabilities,  revenues  and expenses is
        included in the appropriate classification in the financial statements.

                  For financial  reporting purposes the Partnership  follows the
        "full-cost"  method of accounting for nonoperating  interests in oil and
        gas property costs. Under this method of accounting,  all costs incurred
        in the acquisition of  nonoperating  interests in oil and gas properties
        are capitalized.  The unamortized cost of nonoperating  interests in oil
        and gas  properties is limited to the "ceiling  limitation"  (calculated
        separately for the Partnership,  limited partners and general partners).
        The  "ceiling  limitation"  is  calculated  on  a  quarterly  basis  and
        represents the estimated future net revenues from nonoperating interests
        in proved  properties  using current prices,  discounted at ten percent.
        Proceeds from the sale or disposition of  nonoperating  interests in oil
        and  gas  properties  are  treated  as a  reduction  of the  cost of the
        nonoperating  interests  with no gains or  losses  recognized  except in
        significant transactions.

                  The Partnership computes the provision for amortization of oil
        and gas properties on the units-of-production method. Under this method,
        the provision is calculated by multiplying the total unamortized cost of
        oil and gas  properties  by an overall rate  determined  by dividing the
        physical  units of oil and gas  produced  during the period by the total
        estimated proved oil and gas reserves at the beginning of the period.

                  The calculation of the "ceiling  limitation" and the provision
        for  depreciation,  depletion and  amortization is based on estimates of
        proved reserves. There are numerous uncertainties inherent in estimating
        quantities  of proved  reserves  and in  projecting  the future rates of
        production,  timing and plan of development. The accuracy of any reserve
        estimate  is a  function  of  the  quality  of  available  data  and  of
        engineering  and  geological  interpretation  and  judgment.  Results of
        drilling,  testing and production subsequent to the date of the estimate
        may justify revision of such estimate.  Accordingly,  reserve  estimates
        are  often  different  from  the  quantities  of oil  and gas  that  are
        ultimately recovered.

(4)  Related-Party Transactions -

                  An  affiliate  of  the  Special  General  Partner,  as  Dealer
        Manager,  received  $99,177 for managing and  overseeing the offering of
        the limited  partnership units. A one-time management fee of $99,577 was
        paid to Swift for services performed for the Partnership.

                  The  Partnership  entered  into a Net Profits  and  Overriding
        Royalty Interests Agreement ("NP/OR Agreement") with Swift Energy Income
        Partners 1989-B, Ltd. ("Operating  Partnership"),  managed by Swift, for
        the purpose of acquiring nonoperating interests in producing oil and gas
        properties. Under terms of the NP/OR Agreement, the Partnership has been
        conveyed a  nonoperating  interests in the aggregate net profits  (i.e.,
        oil and gas  sales net of  related  operating  costs) of the  properties
        acquired equal to its  proportionate  share of the property  acquisition
        costs.

                                       7


<PAGE>


          SWIFT ENERGY MANAGED PENSION ASSETS PARTNERSHIP 1989-B, LTD.
                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)
                                   (UNAUDITED)


(5)  Vulnerability Due to Certain Concentrations -

                  The  Partnership's  revenues are primarily the result of sales
        of its oil and natural gas production.  Market prices of oil and natural
        gas may fluctuate and adversely affect operating results.

                  In the normal  course of  business,  the  Partnership  extends
        credit,  primarily in the form of monthly oil and gas sales receivables,
        to various  companies  in the oil and gas  industry  which  results in a
        concentration  of credit risk. This  concentration of credit risk may be
        affected by changes in economic or other  conditions and may accordingly
        impact the  Partnership's  overall  credit risk.  However,  the Managing
        General  Partner  believes  that  the  risk is  mitigated  by the  size,
        reputation, and nature of the companies to which the Partnership extends
        credit.  In  addition,   the  Partnership  generally  does  not  require
        collateral or other security to support customer receivables.

(6)  Fair Value of Financial Instruments -

                  The Partnership's  financial  instruments  consist of cash and
        cash equivalents and short-term  receivables and payables.  The carrying
        amounts  approximate  fair value due to the highly  liquid nature of the
        short-term instruments.

(7)  Year 2000 -

                  The  Year  2000  issue  results  from  computer  programs  and
        embedded computer chips with date fields that cannot distinguish between
        the years 1900 and 2000.  The  Managing  General  Partner  is  currently
        implementing  the steps necessary to make its operations and the related
        operations of the Partnership capable of addressing the Year 2000. These
        steps include upgrading, testing and certifying its computer systems and
        field   operation   services   and   obtaining   Year  2000   compliance
        certification  from  all  important  business  suppliers.  The  Managing
        General Partner formed a task force during 1998 to address the Year 2000
        issue and prepare its business  systems for the Year 2000.  By mid-1999,
        the Managing  General Partner expects the mission critical systems to be
        either replaced or updated and testing to be virtually completed.


                                       8

<PAGE>

          SWIFT ENERGY MANAGED PENSION ASSETS PARTNERSHIP 1989-B, LTD.
                    NOTES TO FINANCIAL STATEMENTS (CONTINUED)
                                   (UNAUDITED)


                  The Managing  General  Partner's  business  systems are almost
        entirely  comprised of  off-the-shelf  software.  Most of the  necessary
        changes in computer  instructional  code can be made by  upgrading  this
        software.  The Managing  General  Partner is currently in the process of
        either upgrading the off-the-shelf  software or receiving  certification
        as to Year 2000  compliance from vendors or third party  consultants.  A
        testing phase is being conducted as the software is updated or certified
        and is expected to be completed by mid-1999.

                  The  Managing  General  Partner  does not  believe  that costs
        incurred  to address  the Year 2000 issue with  respect to its  business
        systems  will have a  material  effect on the  Partnership's  results of
        operations,  or its  liquidity and  financial  condition.  The estimated
        total cost to the Managing  General  Partner to address Year 2000 issues
        is  projected  to be less  than  $150,000,  most of which  will be spent
        during  the  testing  phase.  The  Partnership's  share of this  cost is
        expected to be insignificant.

                  The  failure  to correct a material  Year 2000  problem  could
        result  in an  interruption,  or  failure  of  certain  normal  business
        activities or  operations.  Based on  activities  to date,  the Managing
        General  Partner  believes that it will be able to resolve any Year 2000
        problems  concerning  its financial and  administrative  systems.  It is
        undeterminable  how all the  aspects  of the Year 2000 will  impact  the
        Partnership.  The most  reasonably  likely  worst  case  scenario  would
        involve a prolonged disruption of external power sources upon which core
        equipment   relies,   resulting  in  a   substantial   decrease  in  the
        Partnership's  oil and  gas  production  activities.  In  addition,  the
        pipeline  operators  to whom the  Managing  General  Partner  sells  the
        Partnership's  natural gas, as well as other  customers  and  suppliers,
        could be prone to Year  2000  problems  that  could not be  assessed  or
        detected by the Managing General  Partner.  The Managing General Partner
        is contacting  its major  purchasers,  customers,  suppliers,  financial
        institutions  and others  with whom it conducts  business  to  determine
        whether  they will be able to resolve  in a timely  manner any Year 2000
        problems directly  affecting the Managing General Partner or Partnership
        and to inform them of the Managing General Partner's internal assessment
        of its Year 2000  review.  There  can be no  assurance  that such  third
        parties will not fail to appropriately address their Year 2000 issues or
        will not  themselves  suffer a Year 2000  disruption  that  could have a
        material  adverse  effect  on the  Partnership's  activities,  financial
        condition  or  operating  results.  Based upon these  responses  and any
        problems  that arise  during the  testing  phase,  contingency  plans or
        back-up systems would be determined and addressed.

                                       9


<PAGE>

          SWIFT ENERGY MANAGED PENSION ASSETS PARTNERSHIP 1989-B, LTD.
                MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
                       CONDITION AND RESULTS OF OPERATIONS


GENERAL

         The  Partnership is formed for the purpose of investing in nonoperating
interests in producing oil and gas  properties  located  within the  continental
United States.  In order to accomplish  this, the  Partnership  goes through two
distinct yet  overlapping  phases with respect to its  liquidity  and results of
operations.  When the  Partnership  is formed,  it commences  its  "acquisition"
phase,  with all funds placed in short-term  investments  until required for the
acquisition of nonoperating interests.  Therefore,  the interest earned on these
pre-acquisition  investments  becomes the  primary  cash flow source for initial
partner  distributions.  As the Partnership acquires  nonoperating  interests in
producing properties,  net cash from ownership of nonoperating interests becomes
available  for  distribution,  along  with  the  investment  income.  After  all
partnership funds have been expended on nonoperating  interests in producing oil
and gas properties,  the Partnership enters its "operations"  phase. During this
phase,  income  from  nonoperating  interests  in oil  and gas  sales  generates
substantially all revenues, and distributions to partners reflect those revenues
less all  associated  partnership  expenses.  The  Partnership  may also  derive
proceeds  from  the  sale of  nonoperating  interests  in  acquired  oil and gas
properties,  when the sale of such  interests  is  economically  appropriate  or
preferable to continued operations.

LIQUIDITY AND CAPITAL RESOURCES

      Oil and gas reserves are depleting  assets and therefore often  experience
significant  production  declines each year from the date of acquisition through
the end of the life of the  property.  The primary  source of  liquidity  to the
Partnership comes almost entirely from the income generated from the sale of oil
and gas produced from ownership  interests in oil and gas  properties.  Net cash
provided by (used in) operating  activities  totaled  $(64,826) and $118,298 for
the three  months  ended March 31, 1999 and 1998,  respectively.  This source of
liquidity and the related results of operations, and in turn cash distributions,
will decline in future periods as the oil and gas produced from these properties
also  declines  while  production  and general and  administrative  costs remain
relatively  stable  making  it  unlikely  that  the  Partnership  will  hold the
properties  until they are fully  depleted,  but will  likely  liquidate  when a
substantial  majority  of the  reserves  have been  produced.  Cash  provided by
proceeds from the sale of nonoperating  interests in properties  totaled $97,716
for the three months ended March 31, 1999. The  Partnership  has expended all of
the  partners'  net  commitments   available  for  property   acquisitions   and
development  by acquiring  producing  oil and gas  properties.  The  partnership
invests  primarily in proved producing  properties with nominal levels of future
costs of development for proven but undeveloped reserves.  Significant purchases
of additional reserves or extensive drilling activity are not anticipated.  Cash
distributions  totaled $31,081 and $157,594 for the three months ended March 31,
1999 and 1998, respectively.

      Under the NP/OR Agreement, the Managing General Partner acquires interests
in oil and gas properties  from outside  parties and sells these interests to an
affiliated  operating  partnership,  who  in  turn  creates  and  sells  to  the
Partnership  nonoperating  interests in these same oil and gas  properties.  The
Managing  General Partner expects funds available from net profits  interests to
be distributed to the partners.

RESULTS OF OPERATIONS

      Income  from  nonoperating  interests  increased  14  percent in the first
quarter of 1999 when  compared  to the same  quarter in 1998.  Oil and gas sales
increased  $5,334 or 4 percent in the first quarter of 1999 when compared to the
corresponding  quarter in 1998,  primarily  due to the release of suspended  gas
revenue from a  non-operated  well in Arkansas.  Current  quarter gas production
increased  47  percent  as a result  of the  released  gas  revenue,  while  oil
production  declined 30 percent when compared to first  quarter 1998  production
volumes.  The sale of the Caprito field in Texas in February 1999, had an impact
on oil  production  for the  quarter.  Gas and oil  prices  remained  flat at an
average $1.97/MCF for gas and $12.71/BBL for oil for the quarter.

      Corresponding  production costs per equivalent MCF decreased 29 percent in
the  first  quarter  of 1999  compared  to the  first  quarter  of 1998 as total
production  costs  decreased 21 percent,  relating to the property  sales in the
current quarter.

      Total amortization expense increased 1 percent or $730 in 1999 compared to
first quarter 1998.

      Partnership payout occurred as of January 1,1998. During 1999, partnership
revenues  and costs will be shared  between  the  limited  partners  and general
partners in an 85:15 ratio.


                                        10


<PAGE>

          SWIFT ENERGY MANAGED PENSION ASSETS PARTNERSHIP 1989-B, LTD.
                           PART II - OTHER INFORMATION



ITEM 5.    OTHER INFORMATION




                                     -NONE-





                                       11


<PAGE>


                                   SIGNATURES



Pursuant to the  requirements of Section 13 or 15(d) 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.


                                             SWIFT ENERGY MANAGED PENSION
                                             ASSETS PARTNERSHIP 1989-B, LTD.
                                             (Registrant)

                                  By:        SWIFT ENERGY COMPANY
                                             Managing General Partner


Date:     May 5, 1999             By:        /s/ John R. Alden
          -----------                        ----------------------------------
                                             John R. Alden
                                             Senior Vice President, Secretary
                                             and Principal Financial Officer

Date:     May 5, 1999             By:        /s/ Alton D. Heckaman, Jr.
          -----------                        ----------------------------------
                                             Alton D. Heckaman, Jr.
                                             Vice President, Controller
                                             and Principal Accounting Officer


                                       12