SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549

                                   FORM 11-K

[X]  ANNUAL REPORT PURSUANT TO SECTION 15 (D) OF THE SECURITIES EXCHANGE ACT OF
     1934

     For the fiscal year ended December 31, 1999

[ ]  TRANSITION REPORT PURSUANT TO SECTION 15(D) OF THE SECURITIES EXCHANGE ACT
     OF 1934 (NO FEE REQUIRED)

     For the transition period from      to

     Commission file number 333-37959

A.   Full title of the plan:

                      RCN SAVINGS & STOCK OWNERSHIP PLAN


B.   Name of issuer of the securities held pursuant to the plan and the address
     of its principal executive office:

                                RCN CORPORATION
                              105 Carnegie Center
                          Princeton, New Jersey 08540


RCN Corporation
RCN Savings & Stock Ownership Plan
Table of Contents
December 31, 1999 and 1998
- -------------------------------------------------------------------------------


                                                               
                                                                       Pages
                                                                       -----


Report of Independent Accountants                                          1

Financial Statements:
 Statements of Net Assets Available for Benefits                           2
 Statement of Changes in Net Assets Available for Benefits                 3
 Notes to Financial Statements                                          4-10

Supplemental Schedules:
 Schedule H Item 4(i)* -Assets Held for Investment Purposes               11

 Schedule H Item 4(j)* -Reportable Transactions                           12




          *Refer to item numbers in Form 5500 (Annual Return/Report of
           Employee Benefit Plan) for the plan periods ended December 31,
           1999, which items are incorporated herein by reference


                       REPORT OF INDEPENDENT ACCOUNTANTS


To the Participants and Administrator of
RCN Savings & Stock Ownership Plan

In our opinion, the accompanying statements of net assets available for benefits
and the related statement of changes in net assets available for benefits
present fairly, in all material respects, the net assets available for benefits
of the RCN Savings & Stock Ownership Plan (the "Plan") at December 31, 1999 and
1998 and the changes in net assets available for benefits for the year ended
December 31, 1999 in conformity with generally accepted accounting principles.
These financial statements are the responsibility of the Plan's management; our
responsibility is to express an opinion on these financial statements based on
our audits.  We conducted our audits of these statements in accordance with
auditing standards generally accepted in the United States, which require that
we plan and perform the audit to obtain reasonable assurance about whether the
financial statements are free of material misstatement.  An audit includes
examining, on a test basis, evidence supporting the amounts and disclosures in
the financial statements, assessing the accounting principles used and
significant estimates made by management, and evaluating the overall financial
statement presentation.  We believe that our audits provide a reasonable basis
for the opinion expressed above.

Our audits were conducted for the purpose of forming an opinion on the basic
financial statements taken as a whole.  The supplemental schedules of Assets
Held for Investment Purposes and Reportable Transactions are presented for the
purpose of additional analysis and are not a required part of the basic
financial statements but are supplementary information required by the
Department of Labor's Rules and Regulations for Reporting and Disclosure under
the Employee Retirement Income Security Act of 1974.  These supplemental
schedules are the responsibility of the Plan's management.  These supplemental
schedules have been subjected to the auditing procedures applied in the audits
of the basic financial statements and, in our opinion, are fairly stated in all
material respects in relation to the basic financial statements taken as a
whole.



/s/ PricewaterhouseCoopers LLP


June 28, 2000

RCN Corporation
RCN Savings & Stock Ownership Plan
Statement of Net Assets Available for Benefits
December 31, 1999 and 1998
- ------------------------------------------------------------------------

                                        1999          1998

Investments (see Note 4)            $37,270,594   $17,739,945
Receivables:
   Employer contributions                88,682       104,016
   Participant contributions            279,382       228,463
   Dividends                             23,560          --
                                    -----------   -----------

Net assets available for benefits   $37,662,218   $18,072,424
                                    ===========   ===========


                     The accompanying notes are an integral
                        part of the financial statements


                                      -2-


RCN Corporation
RCN Savings & Stock Ownership Plan
Statement of Changes in Net Assets Available for Benefits
For the year ended December 31, 1999
- ------------------------------------------------------------------------


Additions:
 Employer contributions                                       $ 2,900,236
 Participant contributions                                      5,652,385
 Interest                                                          47,124
 Dividends                                                        887,086
 Net appreciation in fair value of investments (see Note 4)    14,338,550
                                                              -----------
            Total additions                                    23,825,381
                                                              -----------


Deductions:
 Benefits paid to participants                                  4,217,292
 Administrative fees                                                6,300
 Transfer of assets to other plans                                 11,995
                                                              -----------
            Total deductions                                    4,235,587
                                                              -----------

Increase in net assets available for benefits                  19,589,794

Net assets available for benefits:
 Beginning of year                                             18,072,424
                                                              -----------

 End of year                                                  $37,662,218
                                                              ===========


                     The accompanying notes are an integral
                        part of the financial statements.


                                      -3-




RCN Corporation
RCN Savings & Stock Ownership Plan
Notes to Financial Statements
December 31, 1999 and 1998
- --------------------------------------------------------------------------------

1.DESCRIPTION OF PLAN

  The following brief description of RCN Savings and Stock Ownership Plan (the
  "Plan") is provided for general information purposes only.  Participants
  should refer to the Plan agreement for a more complete description of the
  Plan's provisions.

  GENERAL
  The Plan, established on October 1, 1997, is a defined contribution plan
  covering substantially all employees of RCN Corporation and its subsidiaries
  (the "Company") who have attained the age of twenty-one and have three months
  of enlisted service.  The Plan is subject to the provisions of the Employee
  Retirement Income Security Act of 1974.

  CONTRIBUTIONS
  Participants in the Plan may contribute between 1% and 15% of their annual
  compensation.  Participants may also contribute amounts representing
  distributions from other qualified defined benefit or contribution plans.  The
  Company contributes on behalf of each participant an amount not to exceed 100%
  of the first 3.5% of the participant's compensation.  All Company
  contributions are used to purchase common stock of RCN. Contributions are
  subject to certain limitations.

  Participants may change salary deferral elections as of each of the following
  entry dates (January 1, April 1, July 1 and October 1).  Participants may
  change investment elections on a daily basis, subject to limitations on RCN
  stock.

  PARTICIPANT'S ACCOUNT
  Each participant's account is credited with the participant's contribution and
  allocations of the Company's contribution and Plan earnings, and charged with
  an allocation of administrative expenses.  Allocations are based upon
  participant earnings or account balances, as defined.  The benefit to which a
  participant is entitled is the benefit that can be provided from the
  participant's account balance.

  VESTING
  Participants are immediately vested in their contributions plus actual
  earnings thereon.  Vesting in the Company's matching contribution portion of
  their accounts plus earnings thereon is based on years of continuous service.
  A participant is 100 percent vested after five years of credited service.

  PLAN BENEFITS
  On termination of service due to death, disability or retirement, a
  participant may elect to receive a lump-sum distribution if the value of the
  participant's account is less than or equal to $5,000.  If the value of the
  participant's account is greater than $5,000 and the participant rolled over
  money from a qualified plan, the participant may elect to have their benefit
  paid out in an annuity.

  A participant may elect to have the lump-sum distribution paid in cash or RCN
  Corporation common stock.  If a member elects to receive stock, only whole
  shares are distributed with cash being distributed in lieu of fractional
  shares.

                                      -4-


RCN Corporation
RCN Savings & Stock Ownership Plan
Notes to Financial Statements
December 31, 1999 and 1998
- --------------------------------------------------------------------------------

  Additionally, the Plan permits participants to withdraw a portion or all of
  their vested account balance.  These special distributions include in service
  distributions and hardship withdrawals.  An active participant may request an
  in service distribution upon attaining age 59  1/2.  A hardship withdrawal may
  be granted to a participant for emergency circumstances as defined by the
  Plan.

  PARTICIPANT LOANS
  Participants may borrow from their fund accounts the lesser of 50% of their
  vested account balance or $50,000, subject to a minimum of $1,000.  Loan
  transactions are treated as a transfer to (from) the investment fund from (to)
  the Loan Fund.  Loan terms range from 1-5 years unless the loan is for the
  purchase of a primary residence, for which the term is 30 years.  The loans
  are secured by the balance in the participant's account and bear interest at
  the prime rate plus one basis point.  Principal and interest is paid ratably
  through monthly payroll deductions.

  FORFEITURED ACCOUNTS
  At December 31, 1999, forfeited nonvested accounts totaled $222,235.  These
  accounts will be used to reduce future employer contributions.  Also, in 1999,
  there were no forfeitures used to reduce employer contributions.


2.SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

  BASIS OF ACCOUNTING
  The financial statements of the Plan are prepared under the accrual method of
  accounting.

  INVESTMENT VALUATION AND INCOME RECOGNITION
  The Plan's investments are stated at fair value.  Shares of registered
  investment companies are valued at quoted market prices which represent the
  net asset value of shares held by the Plan at year-end.  The guaranteed
  investment contracts held in the Merrill Lynch Retirement Preservation Trust
  Fund are valued at fair value.  The Company stock is valued at its quoted
  market price.  Participant loans are valued at cost which approximates fair
  value.

  Purchases and sales of securities are recorded on a trade-date basis.
  Interest income is recorded on the accrual basis.  Dividends are recorded on
  the ex-dividend date.

  The Plan presents in the statement of changes in net assets available for
  benefits the net appreciation (depreciation) in the fair value of its
  investments which consists of the realized gains or losses and the unrealized
  appreciation (depreciation) on those investments.

  INVESTMENTS IN COMMON COLLECTIVE TRUST
  The Merrill Lynch Retirement Preservation Trust Fund (the "Trust Fund")
  invests in various term guaranteed insurance contracts and maintains a cash
  reserve balance with all excess funds.  The average yield and the weighted
  average crediting interest rate are based on the underlying contracts.

                                      -5-


RCN Corporation
RCN Savings & Stock Ownership Plan
Notes to Financial Statements
December 31, 1999 and 1998
- --------------------------------------------------------------------------------


  The Trust Fund's investment contracts are reported at their estimated fair
  value.  The investment contracts are nontransferable but provide for benefit
  responsive withdrawals by plan participants at contract value.  Benefit
  responsive withdrawals are provided for on a proportional basis by the issuers
  of the investment contracts.  In determining fair value, the Plan's trustee's
  valuation committee primarily considers such factors as the benefit
  responsiveness of the investment contract and the ability of the parties to
  the investment contract to perform in accordance with the terms of the
  contract.  Generally, fair value approximates contract value (contributions
  made plus interest accrued at the current rate, less withdrawals and fees).
  If, however, an event has occurred that may impair the ability of the contract
  issuer to perform in accordance with the contract terms, fair value may be
  less than contract value.  The contract value of the Trust Fund at December
  31, 1999 and 1998 is $2,166,691 and $1,640,716, respectively.

  The average yield and crediting interest rates were approximately 6 percent
  for the years ended December 31, 1999 and 1998.

  EXPENSES OF THE PLAN
  Fees and other costs incurred are paid by the Plan, then allocated to each
  investment fund.

  BENEFIT PAYMENTS
  Benefits are recorded when paid.

  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 net assets and changes therein, and
  disclosure of contingent assets and liabilities.  Actual results could differ
  from those estimates.

  RISKS AND UNCERTAINTIES
  The Plan provides for various investment options in any combination of stocks,
  bonds, fixed income securities, mutual funds, and other investment securities.
  Investment securities are exposed to various risks, such as interest rate,
  market and credit.  Due to the level of risk associated with certain
  investment securities and the level of uncertainty related to changes in the
  value of investment securities, it is at least reasonably possible that
  changes in risks in the near term could materially affect participants'
  account balances and the amounts reported in the statements of net assets
  available for benefits and the statements of changes in net assets available
  for benefits.

                                      -6-


RCN Corporation
RCN Savings & Stock Ownership Plan
Notes to Financial Statements
December 31, 1999 and 1998
- --------------------------------------------------------------------------------

3.INVESTMENT OPTIONS

  The investment options of the Plan are as follows:

  MERRILL LYNCH RETIREMENT PRESERVATION TRUST FUND
  This Merrill Lynch Trust account is made up primarily of guaranteed investment
  contracts generally issued by an insurance company or a bank returning
  guaranteed principal and interest to the fund.  A lesser portion of the fund
  is composed of high-quality money market investments.

  MERRILL LYNCH S&P 500 INDEX FUND
  This Merrill Lynch Fund seeks to provide investment results that replicate the
  total return of the Standard & Poor's 500 Composite Stock Price Index (S&P 500
  Index).  The fund generally allocates its investments among common stocks in
  approximately the same weightings as the S&P 500 Index.

  MERRILL LYNCH GROWTH FUND
  This Merrill Lynch Fund provides for a return on investment based on the
  performance of equity securities comprising the fund.

  MERRILL LYNCH CAPITAL FUND
  This Merrill Lynch Fund provides for a return on investment based on the
  performance of a balanced investment in equity, debt, convertible, and money
  market securities.

  MERRILL LYNCH BASIC VALUE FUND
  This Merrill Lynch Fund invests primarily in stocks that appear undervalued,
  especially those selling at a discount from book value or at low
  price/earnings ratios.  The investment goal is capital appreciation.

  MERRILL LYNCH CORPORATE BOND FUND
  This Merrill Lynch Fund provides for a return on investment based on the
  performance of investment grade fixed income securities comprising the fund.

  DREYFUS PREMIUM WORLDWIDE GROWTH FUND
  This Dreyfus Fund invests primarily in equity securities of large
  capitalization multinational corporations.  The investment goal of the fund is
  long-term growth.

  VAN KAMPEN AMERICAN VALUE FUND
  This Van Kampen Fund invests primarily in stocks of small- and mid-cap
  companies which it believes are temporarily undervalued.  The Fund seeks to
  capitalize on the potential appreciation of the companies it believes are
  undervalued.

  VAN KAMPEN AMERICAN EMERGING GROWTH FUND
  This Van Kampen Fund invests primarily in the stocks of emerging mid-cap
  companies that have significant growth potential.  The objective of the Fund
  is long-term capital appreciation.

                                      -7-


RCN Corporation
RCN Savings & Stock Ownership Plan
Notes to Financial Statements
December 31, 1999 and 1998
- --------------------------------------------------------------------------------

  PIMCO HIGH YIELD FUND
  This PIMCO Fund invests in fixed income securities of companies in the upper
  and middle credit quality tiers of the high yield market.  By focusing on
  better quality high yield investments, the fund seeks to reduce exposure to
  more risky high yield bonds without sacrificing return potential.

  ALLIANCE QUASAR FUND
  This Alliance Fund invests in widely diversified portfolios of equity
  securities spread among many industries that offer the possibility of above-
  average earnings growth.

  IVY INTERNATIONAL FUND
  This Ivy Mackenzie Fund invests primarily in stocks of European, Pacific Basin
  and South American Markets.  The investment goal is long-term capital
  appreciation.

  MASS INVESTORS GROWTH FUND
  This MFS Fund invests in equity securities of companies believed to have
  better-than-average long-term growth potential.  The objective of the fund is
  to seek long-term growth of capital and future income rather than current
  income.

  RCN COMMON STOCK
  Monies invested in this fund are used to purchase common stock of RCN
  Corporation.

  LOAN FUND
  The Fund represents the outstanding principal balance for all participant
  loans.


4. INVESTMENTS

  The following presents investments that represent 5 percent or more of the
  Plan's net assets:


                                                            December 31
                                                    ---------------------------
                                                       1999             1998
Investments at fair value:
   Merrill Lynch Retirement Preservation Trust     $ 2,166,691      $ 1,640,716
   Merrill Lynch Growth Fund                         2,792,961        2,040,109
   Merrill Lynch Capital Fund                        2,071,335        1,974,598
   Merrill Lynch Basic Value Fund                    3,424,330        2,813,215
   Shares of RCN Common Stock*                      21,506,640        7,464,212




                                      -8-



RCN Corporation
RCN Savings & Stock Ownership Plan
Notes to Financial Statements
December 31, 1999 and 1998
- --------------------------------------------------------------------------------


  During 1999, the Plan's investments, including gains and losses on investments
  sold, as well as held during the year, appreciated in value by $14,338,550 as
  follows:

  Merrill Lynch Retirement Preservation Trust                     $        634
  Merrill Lynch S&P 500 Index Fund                                      32,077
  Merrill Lynch Growth Fund                                            578,095
  Merrill Lynch Capital Fund                                          (133,564)
  Merrill Lynch Basic Value Fund                                        (2,443)
  Merrill Lynch Corporate Bond Fund                                    (26,044)
  Dreyfus Premium Worldwide Growth Fund                                 22,005
  Van Kampen American Value Fund                                         8,508
  Van Kampen Emerging Growth Fund                                      230,654
  PIMCO High Yield Fund                                                   (552)
  Alliance Quasar Fund                                                  69,788
  Ivy International Fund                                               103,841
  Mass Investors Growth Stock Fund                                      71,143
  Shares of RCN Common Stock*                                       13,384,408
                                                                  ------------

                                                                  $ 14,338,550
                                                                  ============
*Participant and Nonparticipant directed

5. NONPARTICIPANT DIRECTED INVESTMENTS

  Information about the net assets and significant components of the changes in
  net assets relating to the nonparticipant directed investments is as follows:


                                                             December 31,
                                                        1999            1998

Net assets:
   RCN Common Stock                                 $11,545,261     $ 3,391,657
                                                    -----------     -----------
Changes in net assets:
   Contributions                                                      2,900,105
   Net appreciation in fair value of investments                      7,137,116
   Benefits paid to participants                                     (1,570,752)
   Administrative fees                                                   (1,571)
   Interfund transfers                                                 (311,294)
                                                                    -----------
                                                                    $ 8,153,604
                                                                    ===========

6. PLAN TERMINATION

  Although it has not expressed any intent to do so, the Company has the right
  under the Plan to discontinue its contributions at any time and to terminate
  the Plan subject to the provisions of ERISA.  In the event of Plan
  termination, participants will become 100 percent vested in their accounts.

                                      -9-



RCN Corporation
RCN Savings & Stock Ownership Plan
Notes to Financial Statements
December 31, 1999 and 1998
- --------------------------------------------------------------------------------


7.RELATED PARTY TRANSACTIONS

  Certain Plan investments are shares of mutual funds managed by Merrill Lynch.
  Merrill Lynch is the trustee as defined by the Plan and, therefore, these
  transactions qualify as party-in-interest.  Fees paid by the Plan for the
  investment management services amounted to $6,300 for the year ended December
  31, 1999.

  As described in Note 1, participants may choose to purchase common stock of
  RCN Corporation, the Plan Sponsor.  During 1999, purchases of $7,235,863 were
  made, and proceeds of $5,268,126 were received from sales of RCN Corporation's
  common stock.

8.TAX STATUS

  The Internal Revenue Service has determined and informed the Company by a
  letter dated March 11, 1999, that the Plan and related trust are designed in
  accordance with applicable sections of the Internal Revenue Code (IRC).  The
  Plan administrator and Plan's tax counsel believe that the Plan is designed
  and is currently being operated in compliance with the applicable requirements
  of the IRC.

                                      -10-


RCN Corporation
RCN Savings & Stock Ownership Plan
Schedule H Item 4(i) - Assets Held for Investment Purposes
December 31, 1999
- ------------------------------------------------------------------------------



                   (b)                                          (c)                                    (d)              (e)
(a)         Identity of Issue                           Description of Asset                          Cost        Current Value

                                                                                                             
  *    Merrill Lynch             Merrill Lynch Retirement Preservation Trust                         $ 2,166,737       $ 2,166,691
                                 Merrill Lynch S&P 500 Index Fund                                        440,140           471,837
                                 Merrill Lynch Growth Fund                                             2,546,886         2,792,961
                                 Merrill Lynch Capital Fund                                            2,172,684         2,071,335
                                 Merrill Lynch Basic Value Fund                                        3,293,062         3,424,330
                                 Merrill Lynch Corporate Bond Fund                                       537,492           517,914
                                 Dreyfus Premium Worldwide Growth Fund                                   180,771           199,517
                                 Van Kampen American Value Fund                                          215,724           225,247
                                 Van Kampen Emerging Growth Fund                                         609,440           838,938
                                 PIMCO High Yield Fund                                                    80,918            80,365
                                 Alliance Quasar Fund                                                    535,900           584,357
                                 Ivy International Fund                                                  745,015           823,840
                                 Mass Investors Growth Stock Fund                                        491,601           562,578

  *    RCN Common Stock          Shares of RCN Common Stock                                            9,963,213        21,506,640

  *    Paticipants' Notes        Participants' loans with interest rates from 7.75% to 9.50%
                                    with maturity dates from 2000 to 2028                                  --            1,004,044
                                                                                                     -----------       -----------

                                 Total                                                               $23,979,583       $37,270,594
                                                                                                     -----------       -----------



*Party-in-interest

                                      -11-



RCN Corporation
RCN Savings & Stock Ownership Plan
Schedule H Item (j) - Reportable Transactions
For the year ended December 31, 1999
- ------------------------------------------------------------------------------




        (a)                                  (b)                            Number of     (c) Purchase         (d)
 Identity of Party                   Description of Asset                   Transactions     Price        Selling Price

                                                                                                  
Merrill Lynch*         Merrill Lynch Retirement Preservation Trust                 427      $ 1,224,299                -
                       Merrill Lynch Retirement Preservation Trust                 407                -         $694,449
                       Merrill Lynch Growth Fund                                   334          900,163                -
                       Merrill Lynch Growth Fund                                   162                -          549,676
                       Merrill Lynch Capital Fund                                  157          874,315                -
                       Merrill Lynch Capital Fund                                  299                -          601,302
                       Merrill Lynch Basic Value Fund                              141        1,529,336                -
                       Merrill Lynch Basic Value Fund                              244                -          829,484

RCN Corporation*       Shares of RCN Common Stock                                  427        7,235,863                -
                       Shares of RCN Common Stock                                  407                -        5,268,126






        (a)                                  (b)                           (e)          (f) Current         (g) Net
 Identity of Party                   Description of Asset                  Cost            Value          Gain (Loss)

                                                                                                  
Merrill Lynch*         Merrill Lynch Retirement Preservation Trust       $ 1,224,299      $ 1,224,299                 -
                       Merrill Lynch Retirement Preservation Trust           694,449                -                 -
                       Merrill Lynch Growth Fund                             900,163          900,163                 -
                       Merrill Lynch Growth Fund                             674,630                -        $ (124,954)
                       Merrill Lynch Capital Fund                            874,315          874,315                 -
                       Merrill Lynch Capital Fund                            573,609                -            27,693
                       Merrill Lynch Basic Value Fund                      1,529,336        1,529,336                 -
                       Merrill Lynch Basic Value Fund                        759,742                -            69,742

RCN Corporation*       Shares of RCN Common Stock                          7,235,863        7,235,863                 -
                       Shares of RCN Common Stock                          2,198,248                -         3,069,878




                                      -12-



                                  SIGNATURES

     Pursuant to the requirements of The Securities Exchange Act of 1934, the
trustees have duly caused this annual report to be signed on its behalf by the
undersigned thereunto duly authorized.

RCN SAVINGS & STOCK
OWNERSHIP PLAN

DATE: June 28, 2000             By: /s/ Jonathan R. Parkes
                                    --------------------------
                                    Human Resources
                                    Financial Manager