Under the Securities Exchange Act of 1934
(Amendment No. 1)*

(Name of Issuer)

(Title of Class of Securities)

(CUSIP Number)

(Name, Address and Telephone Number of Person
Authorized to Receive Notices and Communications)

(Date of Event Which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. o

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent.

* The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.

2

3

4

5

6

7

8

9

10

11

Explanatory Note

This Amendment No. 1 to the statement on Schedule 13D amends and supplements the statement on Schedule 13D filed by certain of the Reporting Persons on July 10, 2017 (the “Original Schedule 13D”, and together with this Amendment No. 1, the “Schedule 13D”). Except as amended herein, the Original Schedule 13D remains in full force and effect. Terms defined in the Original Schedule 13D are used herein as so defined, unless otherwise defined herein.

Item 2. Identity and Background

Item 2 of the Original Schedule 13D is hereby amended and restated in its entirety as follows:

(a) This statement is being filed jointly by (i) ASSF IV AIV B Holdings, L.P., (“ASSF IV”), (ii) ASSF Operating Manager IV, L.P. (“ASSF Operating Manager IV”), (iii) Ares Management LLC, (iv) Ares Management Holdings L.P. (“Ares Management Holdings”), (v) Ares Holdco LLC (“Ares Holdco”), (vi) Ares Holdings Inc. (“Ares Holdings”), (vii) Ares Management Corporation (“Ares Management”), (viii) Ares Voting LLC (“Ares Voting”), (ix) Ares Management GP LLC (“Ares Management GP”) and (x) Ares Partners Holdco LLC (“Ares Partners”) (collectively, the “Reporting Persons”). The Reporting Persons have entered into a joint filing agreement, dated as of February 25, 2019, a copy of which is attached hereto as Exhibit 99.2.

(b) The address of the principal office of each of the Reporting Persons, the Board Members (as defined herein) and the other individuals set forth in Schedule A hereto (such other individuals together with the Board Members, the “Managers”) is c/o Ares Management LLC, 2000 Avenue of the Stars, 12th Floor, Los Angeles, California 90067.

(c) The Reporting Persons are either holding companies without operations, or are principally engaged in the business of investment management and investing in securities. The manager of ASSF IV is ASSF Operating Manager IV, and the general partner of ASSF Operating Manager IV is Ares Management LLC. The sole member of Ares Management LLC is Ares Management Holdings and the general partner of Ares Management Holdings is Ares Holdco. The sole member of Ares Holdco is Ares Holdings. The sole stockholder of Ares Holdings is Ares Management. Ares Management GP is the sole holder of the Class B common stock, $0.01 par value per share, of Ares Management (“Class B Common Stock”) and Ares Voting is the sole holder of the Class C common stock, $0.01 par value per share, of Ares Management (“Class C Common Stock”). Pursuant to Ares Management’s Certificate of Incorporation in effect as of the date hereof, the holders of the Class B Common Stock and the Class C Common Stock, collectively, will generally have the majority of the votes on any matter submitted to the stockholders of Ares Management if certain conditions are met. The executive officers and directors of Ares Management and their principal occupations are set forth in Schedule A hereto. The sole member of both Ares Management GP and Ares Voting is Ares Partners. Ares Partners is managed by a board of managers, which is composed of Michael J Arougheti, Ryan Berry, R. Kipp deVeer, David B. Kaplan, Michael R. McFerran, Antony P. Ressler and Bennett Rosenthal (collectively, the “Board Members”). Mr. Ressler generally has veto authority over Board Members’ decisions. The present principal occupation of each of the Board Members is set forth in Schedule A hereto.

Each of the Reporting Persons (other than ASSF IV, with respect to the shares of Common Stock held directly by it), and the Managers, and the other directors, officers, partners, stockholders, members and managers of the Reporting Persons, expressly disclaims beneficial ownership of the shares of Common Stock, for purposes of Section 13(d) of the Act and the rules thereunder.

(d) During the last five years, none of the Reporting Persons or the Managers have been convicted in any criminal proceeding (excluding traffic violations or similar misdemeanors).

(e) During the last five years, none of the Reporting Persons or the Managers have been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction as a result of which proceeding he or she was or is subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

(f) Each of the Reporting Persons is organized in the State of Delaware. Each of the Managers, other than Ryan Berry, is a citizen of the United States. Ryan Berry is a citizen of Canada.

12

Item 4. Purpose of Transaction

Item 4 of the Original Schedule 13D is hereby amended and restated in its entirety as follows:

Pursuant to the terms of the Stock Purchase Agreement, for so long as Ares Management LLC or its affiliated funds or accounts (together, “Ares”) hold debt of the Issuer or any of the Issuer’s subsidiaries in an aggregate principal amount of at least $50 million, Ares shall have the right to appoint one non-voting board observer with respect to the Issuer’s board of directors (the “Board”), and such observer will have the right to (i) receive all information and materials provided to the members of the Board in their capacity as such, and (ii) attend all regularly scheduled meetings of the Board, with certain limitations as specified in the Stock Purchase Agreement.

The Reporting Persons and their respective representatives have, from time to time, engaged in discussions with the Issuer’s management and the Board regarding, among other things, the Issuer’s business strategy, management, governance, strategic transactions, operating performance, financial matters, capital structure and corporate expenses and intend to, from time to time, continue to engage in such discussions with the Issuer’s management and the Board and engage in discussions with other current or prospective holders of shares of Common Stock and/or other equity, debt, notes, instruments or securities, or rights convertible into or exchangeable or exercisable for Common Stock or such other equity, debt, notes, instruments or securities of, the Issuer (collectively, “Securities”), industry analysts, existing or potential strategic partners, acquirers or competitors, financial sponsors, investment firms, investment professionals, capital or potential capital sources and other third parties regarding such matters (in each case, including with respect to providing or potentially providing capital to the Issuer or to existing or potential strategic partners or acquirers of the Issuer). These discussions have encompassed, and the Reporting Persons expect will encompass, a broad range of matters relating to the Issuer, including, among other things, the Issuer’s business, operations, finances, management, organizational documents, ownership, capital and corporate structure, dividend policy, corporate governance, board and committee composition, management and director incentive programs, strategic alternatives and transactions as a means of enhancing the value of one or more Securities held by the Reporting Persons, including the sale of the Issuer, its Securities or certain of its subsidiaries, businesses or assets or a business combination involving the Issuer or its subsidiaries.  The Reporting Persons may exchange information with the Issuer or other persons or entities pursuant to confidentiality or similar agreements.  The Reporting Persons intend to consider, explore and develop plans and make proposals with respect to, among other things, the foregoing matters and may take other steps seeking to bring about changes with respect to the Issuer to increase the value of one or more Securities held by the Reporting Persons as well as pursue other plans or proposals that relate to or could result in any of the matters set forth in clauses (a)-(j) of Item 4 of Schedule 13D.  The Reporting Persons may also take steps to explore or prepare for various plans, proposals or actions, or propose transactions, regarding any of the foregoing matters before forming an intention to engage in any such plans, proposals or actions or proceed with any such transactions.

The Reporting Persons intend to review their investment in the Issuer on an ongoing basis.  Depending on various factors, including, without limitation, the outcome of any discussions referenced above, the Issuer’s business, financial position, results, strategic direction or prospects or any strategic alternatives or transactions, actions taken by the Issuer’s management or the Board, price levels of one or more Securities, other investment opportunities available to the Reporting Persons, conditions in the securities or loan markets, general economic or industry conditions or any changes in law or government regulations, the Reporting Persons may in the future take such actions with respect to their investment in the Issuer as they deem appropriate, including, without limitation, the actions and matters described in the preceding paragraph, acquiring, or causing to be acquired, additional Securities, disposing of, or causing to be disposed, some or all of the Securities beneficially owned by them, in the public market, in privately negotiated transactions or otherwise, modifying or seeking to modify the terms of any Securities held by them including through refinancing of such Securities, entering into derivatives transactions and other agreements or instruments that increase or decrease the Reporting Persons’ economic exposure with respect to their investment in the Issuer, forming joint ventures with the Issuer or with third parties with respect to the Issuer, its assets or Securities, providing debt financing or other forms of capital to the Issuer or to potential strategic partners or acquirers of the Issuer, pledging their interest in Securities as a means of obtaining liquidity or as credit support for loans or other extensions of credit, or forming, making or undertaking other purposes, plans or proposals regarding the Issuer or any of its Securities or its subsidiaries, businesses or assets. If the Reporting Persons were to acquire additional Securities, the Reporting Persons’ ability to influence the Issuer’s management, the Board or the policies of the Issuer may increase.

The information set forth in Item 6 below is incorporated by reference in its entirety into this Item 4.

13

Item 5. Interest in Securities of the Issuer

Item 5 of the Original Schedule 13D is hereby amended and restated in its entirety as follows:

(a) Aggregate number and percentage of securities.

As of the date hereof, ASSF IV directly holds 7,188,615 shares of Common Stock and Warrants that, based on the Fully Diluted Common Stock (as defined in the Warrant Agreement for purposes of determining the conversion rate of the Warrants) as of December 31, 2018 (as reported by the Issuer to the Reporting Persons), are exercisable for 4,500,251 shares of Common Stock. As of the date hereof, an account managed by ASSF Operating Manager IV directly holds Warrants that, based on the Fully Diluted Common Stock as of December 31, 2018 (as reported by the Issuer to the Reporting Persons), are exercisable for 1,500,084 shares of Common Stock. The Reporting Persons, as a result of the relationships described in Item 2, may be deemed to directly or indirectly beneficially own the shares of Common Stock, and the shares of Common Stock underlying Warrants, held by ASSF IV and the managed account, which are reported on the cover pages to this Schedule 13D for such Reporting Persons, as applicable. See also items 11 and 13 of the cover pages to, and Item 2 of, this Schedule 13D for the aggregate number of shares of Common Stock and percentage of Common Stock beneficially owned by each of the Reporting Persons.

Pursuant to Rule 13d-3(d)(1)(i) under the Act, the beneficial ownership disclosed on the cover pages of this Schedule 13D includes shares of Common Stock that currently may be issued upon the exercise of the Warrants described above. The number of shares of Common Stock that may be acquired upon exercise of the Warrants is disclosed based on the Fully Diluted Common Stock of the Issuer outstanding as of December 31, 2018 (as reported by the Issuer to the Reporting Persons). The applicable ownership percentages reported in this Schedule 13D are based on 127,903,339 shares of Common Stock outstanding as of December 31, 2018 (as reported by the Issuer to the Reporting Persons) and 4,500,251 shares of Common Stock issuable upon exercise of the Warrants held by ASSF IV and 1,500,084 shares of Common Stock issuable upon exercise of the Warrants held in the account managed by ASSF Operating Manager IV (such shares of Common Stock issuable upon exercise of such Warrants based on the Fully Diluted Common Stock as of December 31, 2018, as reported by the Issuer to the Reporting Persons) beneficially owned by the Reporting Persons as of the date hereof.

(b) Power to vote and dispose. See items 7 through 10 of the cover pages to, and Item 2 of, this Schedule 13D for the number of shares of Common Stock beneficially owned by each of the Reporting Persons as to which there is sole or shared power to vote or to direct the vote, and sole or shared power to dispose or to direct the disposition. The beneficial ownership disclosed on the cover pages of this Schedule 13D includes shares of Common Stock that may be issued upon the exercise of the Warrants based on the Fully Diluted Common Stock as of December 31, 2018, as reported by the Issuer to the Reporting Persons, as described in Item 5(a) above.

(c) Transactions within the past 60 days. The information set forth in Items 3, 4 and 6 in this Schedule 13D is incorporated herein by reference. Except as otherwise described in this Schedule 13D, none of the Reporting Persons has effected any transaction related to the Common Stock during the past 60 days.

(d) Certain rights of other persons. Except as otherwise described in this Schedule 13D, no other person has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, securities covered by this Schedule 13D.

(e) Date ceased to be a 5% owner. Not applicable.

Item 6. Contracts, Arrangements, Understandings or Relationships with Respect to Securities of the Issuer

Item 6 of the Original Schedule 13D is hereby amended by adding the following:

The Reporting Persons currently own $9,270,000 of aggregate principal amount of the Issuer’s 8.875% senior notes due 2021 (the “Notes”) and as disclosed in Item 4 of this Schedule 13D, the Reporting Persons may, from time to time, dispose of or acquire additional Notes, or other Securities that may be issued by the Issuer, including taking a control position in the Notes or any such other Securities.

The information set forth in Item 4 above is incorporated by reference in its entirety into this Item 6.

Item 7. Material to be Filed as Exhibits

Item 7 of the Original Schedule 13D is hereby amended by adding the following:

14

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, the undersigned certifies that the information set forth in this statement is true, complete and correct.

Date: February 25, 2019

15

16

EXHIBIT INDEX

17

EXHIBIT 99.2

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k)(1) promulgated under the Securities Exchange Act of 1934, as amended, the undersigned hereby agree to the joint filing with each of the Reporting Persons (as such term is defined in the Schedule 13D referred to below) on behalf of each of them of a statement on Schedule 13D (including amendments thereto) with respect to the common stock, par value $0.0001 per share, of BioScrip, Inc., a Delaware corporation, and that this agreement may be included as an exhibit to such joint filing.

IN WITNESS WHEREOF, the undersigned hereby execute this agreement as of February 25, 2019.

1

2

SCHEDULE A

BOARD OF MANAGERS OF

ARES PARTNERS HOLDCO LLC

The address for all of the persons listed above is c/o Ares Management LLC, 2000 Avenue of the Stars, 12th Floor, Los Angeles, California 90067.

3

DIRECTORS AND EXECUTIVE OFFICERS OF

ARES MANAGEMENT CORPORATION

4

The address for all of the persons listed above on this Schedule A is c/o Ares Management LLC, 2000 Avenue of the Stars, 12th Floor, Los Angeles, California 90067.

5