<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 September 30, 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

                - September 30, 1999 and December 31, 1998                                      3

            Statements of Operations

                - Three month and nine month periods ended September 30, 1999 and 1998          4

            Statements of Cash Flows

                - Nine month periods ended September 30, 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                                                                  12


SIGNATURES                                                                                     13
</TABLE>



<PAGE>


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



<TABLE>
<CAPTION>
                                                                                September 30,          December 31,
                                                                                    1999                  1998
                                                                               ---------------       ---------------
                                                                                (Unaudited)
<S>                                                                          <C>                   <C>
ASSETS:

Current Assets:
     Cash and cash equivalents                                               $         19,827      $          1,530
     Nonoperating interests income receivable                                          84,189                56,576
                                                                               ---------------       ---------------
          Total Current Assets                                                        104,016                58,106
                                                                               ---------------       ---------------

Nonoperating interests in oil and gas
     properties, using full cost accounting                                         3,727,825             3,900,701
Less-Accumulated amortization                                                      (3,099,924)           (2,998,631)
                                                                               ---------------       ---------------
                                                                                      627,901               902,070
                                                                               ===============       ===============
                                                                             $        731,917      $        960,176
                                                                               ===============       ===============


LIABILITIES AND PARTNERS' CAPITAL:

Current Liabilities:
     Accounts Payable                                                        $          4,890      $        197,225
                                                                               ---------------       ---------------


Limited Partners' Capital (39,830.64 Limited Partnership
                          Units;  $100 per unit)                                      713,870               755,567

General Partners' Capital                                                              13,157                 7,384
                                                                               ---------------       ---------------
          Total Partners' Capital                                                     727,027               762,951
                                                                               ===============       ===============
                                                                             $        731,917      $        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                       Nine Months Ended
                                                        September 30,                           September 30,
                                              ----------------------------------       ---------------------------------
                                                   1999               1998                 1999               1998
                                              ---------------    ---------------       --------------     --------------
<S>                                         <C>                <C>                   <C>                <C>
REVENUES:
     Income from nonoperating interests     $         67,971   $         44,403      $       211,297    $       196,755
     Interest income                                     196                 65                  299                370
                                              ---------------    ---------------       --------------     --------------
                                                      68,167             44,468              211,596            197,125
                                              ---------------    ---------------       --------------     --------------


COSTS AND EXPENSES:
     Amortization                                     26,500            276,151              101,293            372,712
     General and administrative                       14,882             13,686               54,439             48,402
                                              ---------------    ---------------       --------------     --------------
                                                      41,382            289,837              155,732            421,114
                                              ===============    ===============       ==============     ==============
NET INCOME (LOSS)                           $         26,785   $       (245,369)     $        55,864    $      (223,989)
                                              ===============    ===============       ==============     ==============



Limited Partners' net income (loss)
     per unit                               $           0.48   $          (6.16)     $          0.83    $         (5.62)
                                              ===============    ===============       ==============     ==============
</TABLE>


                 See accompanying notes to financial statements.

                                        4


<PAGE>


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


<TABLE>
<CAPTION>
                                                                                            Nine Months Ended
                                                                                              September 30,
                                                                                   -------------------------------------
                                                                                        1999                  1998
                                                                                   ---------------       ---------------
<S>                                                                              <C>                   <C>
CASH FLOWS FROM OPERATING ACTIVITIES:
     Income (loss)                                                               $         55,864      $       (223,989)
     Adjustments to reconcile income (loss) to
          net cash provided by operations:
          Amortization                                                                    101,293               372,712
          Change in assets and liabilities:
               (Increase) decrease in nonoperating interests income receivable            (27,613)               65,145
               Increase (decrease) in accounts payable                                   (192,335)              186,697
                                                                                   ---------------       ---------------
          Net cash provided by (used in) operating activities                             (62,791)              400,565
                                                                                   ---------------       ---------------

CASH FLOWS FROM INVESTING ACTIVITIES:
     Additions to nonoperating interests in oil and gas properties                        (10,772)              (73,380)
     Proceeds from sales of nonoperating interests in oil and gas properties              183,648                    --
                                                                                   ---------------       ---------------
          Net cash provided by (used in) investing activities                             172,876               (73,380)
                                                                                   ---------------       ---------------

CASH FLOWS FROM FINANCING ACTIVITIES:
     Cash Distributions to partners                                                       (91,788)             (393,333)
                                                                                   ---------------       ---------------
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS                                       18,297               (66,148)
                                                                                   ---------------       ---------------
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD                                            1,530                67,645
                                                                                   ===============       ===============
CASH AND CASH EQUIVALENTS AT END OF PERIOD                                       $         19,827      $          1,497
                                                                                   ===============       ===============


Supplemental disclosure of cash flow information:
     Cash paid during the period for interest                                    $          2,267      $          3,645
                                                                                   ===============       ===============
</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 90 percent by the limited  partners and 10 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)


      Oil and Gas Revenues -

                  Oil and gas revenues are reported using the entitlement method
        in which the Partnership  recognizes its interest in oil and natural gas
        production as revenue.

     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 statement.

                  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  Operating
        Partnership will convey to the Partnership 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.

(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.

                                       7

<PAGE>


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


                  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 has  implemented
        the steps necessary to make its operations and the related operations of
        the  Partnership  capable  of  addressing  the Year  2000.  These  steps
        included  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.  The Managing
        General Partner has either replaced or updated mission  critical systems
        and has  substantially  completed  testing  and will  continue  remedial
        actions as needed.

                  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 were made by  upgrading  this
        software.  In  addition,  the  Managing  General  Partner  has  received
        certification  as to Year 2000  compliance  from  vendors or third party
        consultants.

                  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 was spent during
        the testing phase. The  Partnership's  share of this cost is expected to
        be insignificant.



                                       8


<PAGE>


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


                  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 has resolved 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
         has contacted 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, 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. 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 distributions to
partners are determined  quarterly,  based upon the net profits interest payment
received   from  the   companion   operating   partnership,   less  general  and
administrative  expenses.  The net profits  interest payment is determined based
upon net proceeds  from sale of oil and gas  production  after  payment of lease
operating expense, taxes and development costs. In addition,  future partnership
cash requirements are taken into account to determine necessary cash reserves.

      Net cash provided by (used in) operating  activities totaled $(62,791) and
$400,565 for the nine months ended  September  30, 1999 and 1998,  respectively.
Cash  used in  operating  activities  in  1999  is  related  to an  increase  in
nonoperating  interests  income  receivable  and a decrease in accounts  payable
related to prior period well costs.  Cash  provided by proceeds from the sale of
nonoperating  interests in properties totaled $183,648 for the nine months ended
September 30, 1999. Cash distributions totaled $91,788 and $393,333 for the nine
months  ended  September  30,  1999  and  1998,  respectively.   In  1999,  cash
distributions  were effected by the use of available  cash to repay prior period
well  costs,  production  declines  from the  Partnership's  depleting  property
interests,  property sales and low oil and gas prices  received during the first
part of this year.

      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.  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

      The  following  analysis  explains  changes  in the  revenue  and  expense
categories  for the quarter  ended  September  30, 1999  (current  quarter) when
compared to the quarter ended September 30, 1998  (corresponding  quarter),  and
for the nine months ended September 30, 1999 (current period),  when compared to
the nine months ended September 30, 1998 (corresponding period).

                                       10

<PAGE>


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


Three Months Ended September 30, 1999 and 1998

      Income  from  nonoperating  interests  increased  53  percent in the third
quarter of 1999 when  compared  to the same  quarter in 1998.  Oil and gas sales
increased  $36,721 or 43 percent in the third  quarter of 1999 when  compared to
the  corresponding  quarter  in 1998,  primarily  due to  increased  oil and gas
prices. Oil prices increased 48 percent or $5.89/BBL to an average of $18.07/BBL
and gas prices  increased 43 percent or $.90/MCF to an average of $3.01/MCF  for
the quarter.  Increased oil and gas prices helped offset the effect of decreased
production.  Current quarter  production volumes decreased 11 percent as oil and
gas production declined 3 percent and 16 percent, respectively, when compared to
third quarter 1998 production volumes.

      Corresponding  production costs per equivalent MCF increased 58 percent in
the  third  quarter  of 1999  compared  to the third  quarter  of 1998 and total
production costs increased 41 percent.

      Total  amortization  expense for the third  quarter of 1999  decreased  90
percent or $249,651 when  compared to the third  quarter of 1998.  In 1998,  two
components, the normal provision,  calculated on the units of production method,
and the additional provision,  relating to the ceiling limitation, make up total
amortization  expense.  Normal  amortization  expense  decreased  33  percent or
$13,250 in the third quarter of 1999 compared to the third quarter of 1998.

      The  Partnership  recorded an additional  provision in amortization in the
third quarter of 1998 for $236,401,  when the present  value,  discounted at ten
percent, of estimated future net revenues from oil and gas properties, using the
guidelines of the Securities and Exchange Commission,  was below the fair market
value for oil and gas properties resulting in a full cost ceiling impairment.

Nine Months Ended September 30, 1999 and 1998

      Income from nonoperating  interests  increased 7 percent in the first nine
months  of 1999 when  compared  to the same  period  in 1998.  Oil and gas sales
increased $11,919 or 4 percent in the first nine months of 1999 when compared to
the corresponding period in 1998, primarily due to increased oil and gas prices.
Oil prices increased 41 percent or $5.15/BBL to an average of $17.79/BBL and gas
prices  increased  10 percent or  $.21/MCF  to an average of  $2.34/MCF  for the
current  period.  Increased  oil and gas  prices  helped  offset  the  effect of
decreased production.  Current period production volumes decreased 13 percent as
oil production declined 28 percent and 3 percent, respectively, when compared to
the same period in 1998.

      Corresponding  production costs per equivalent MCF increased 13 percent in
the first nine months of 1999 compared to the  corresponding  period in 1998 and
total production costs decreased 2 percent.

      Total amortization  expense for the first nine months of 1999 decreased 73
percent or $271,419 when compared to the first nine months of 1998. In 1998, two
components, the normal provision,  calculated on the units of production method,
and the additional provision,  relating to the ceiling limitation, make up total
amortization  expense.  Normal  amortization  expense  decreased  26  percent or
$35,018 in the first nine  months of 1999  compared  to the first nine months of
1998.

      The  Partnership  recorded an additional  provision in amortization in the
first nine months in 1998 for $236,401,  when the present  value,  discounted at
ten percent, of estimated future net revenues from oil and gas properties, using
the  guidelines of the Securities  and Exchange  Commission,  was below the fair
market  value  for oil and  gas  properties  resulting  in a full  cost  ceiling
impairment.

      During 1999,  partnership  revenues  and costs will be shared  between the
limited partners and general partners in a 85:15 ratio.


                                       11


<PAGE>


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




ITEM 5.    OTHER INFORMATION


                                     -NONE-




                                       12

<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:  November 4, 1999     By:        /s/ John R. Alden
       ----------------                ----------------------------------------
                                       John R. Alden
                                       Senior Vice President, Secretary
                                       and Principal Financial Officer

Date:  November 4, 1999     By:        /s/ Alton D. Heckaman, Jr.
       ----------------                ----------------------------------------
                                       Alton D. Heckaman, Jr.
                                       Vice President, Controller
                                       and Principal Accounting Officer


                                       13