SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

MEDNAX, Inc.

(Name of Issuer)

Common Stock, par value $0.01 per share

(Title of Class of Securities)

58502B106

(CUSIP Number)

Elliott Associates, L.P.

c/o Elliott Management Corporation

40 West 57th Street

New York, NY 10019

with a copy to:

Eleazer Klein, Esq.
Marc Weingarten, Esq.

Schulte Roth & Zabel LLP

919 Third Avenue

New York, New York 10022

(212) 756-2000

(Name, Address and Telephone Number of Person

Authorized to Receive Notices and Communications)

November 6, 2017

(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 Rule 13d-1(e), Rule 13d-1(f) or Rule 13d-1(g), check the following box. [ ]

(Page 1 of 11 Pages)

______________________________

* 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).

CUSIP No. 58502B106 Schedule 13D Page 2 of 11 Pages

1	NAME OF REPORTING PERSON Elliott Associates, L.P.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) x (b) ¨
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDING IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:	7	SOLE VOTING POWER 608,000 (1)
	8	SHARED VOTING POWER 0
	9	SOLE DISPOSITIVE POWER 608,000 (1)
	10	SHARED DISPOSITIVE POWER 0
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH PERSON 608,000 (1)
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			¨
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 0.7%
14	TYPE OF REPORTING PERSON PN

(1) Excludes cash-settled swaps disclosed in Item 5 representing economic exposure comparable to 1,495,999 additional shares of Common Stock (as defined below), which if aggregated with such beneficially owned shares, represent an aggregate economic interest in 2,103,999 shares representing 2.3% of the outstanding shares.

CUSIP No. 58502B106 Schedule 13D Page 3 of 11 Pages

1	NAME OF REPORTING PERSON Elliott International, L.P.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) x (b) ¨
3	SEC USE ONLY
4	SOURCE OF FUNDS WC
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDING IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION Cayman Islands, British West Indies
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:	7	SOLE VOTING POWER 0
	8	SHARED VOTING POWER 1,292,000 (1)
	9	SOLE DISPOSITIVE POWER 0
	10	SHARED DISPOSITIVE POWER 1,292,000 (1)
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH PERSON 1,292,000 (1)
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			¨
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 1.4%
14	TYPE OF REPORTING PERSON PN

(1) Excludes cash-settled swaps disclosed in Item 5 representing economic exposure comparable to 3,179,001 additional shares of Common Stock (as defined below), which if aggregated with such beneficially owned shares, represent an aggregate economic interest in 4,471,001 shares representing of 4.8% of the outstanding shares.

CUSIP No. 58502B106 Schedule 13D Page 4 of 11 Pages

1	NAME OF REPORTING PERSON Elliott International Capital Advisors Inc.
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP		(a) x (b) ¨
3	SEC USE ONLY
4	SOURCE OF FUNDS OO
5	CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDING IS REQUIRED PURSUANT TO ITEMS 2(d) or 2(e)		¨
6	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:	7	SOLE VOTING POWER -0-
	8	SHARED VOTING POWER 1,292,000 (1)
	9	SOLE DISPOSITIVE POWER -0-
	10	SHARED DISPOSITIVE POWER 1,292,000 (1)
11	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH PERSON 1,292,000 (1)
12	CHECK IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES			¨
13	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11) 1.4%
14	TYPE OF REPORTING PERSON CO

(1) Excludes cash-settled swaps disclosed in Item 5 representing economic exposure comparable to 3,179,001 additional shares of Common Stock (as defined below), which if aggregated with such beneficially owned shares, represent an aggregate economic interest in 4,471,001 shares representing of 4.8% of the outstanding shares.

CUSIP No. 58502B106 Schedule 13D Page 5 of 11 Pages

Item 1.	SECURITY AND ISSUER
This statement relates to the shares of common stock, par value $0.01 per share (the "Common Stock"), of MEDNAX, Inc., a Florida corporation (the "Issuer").  The Issuer's principal executive offices are located at 1301 Concord Terrace, Sunrise, Florida 33323.

Item 2. IDENTITY AND BACKGROUND

(a)-(c) This statement is being filed by Elliott Associates, L.P., a Delaware limited partnership, and its wholly-owned subsidiaries (collectively, "Elliott" or "we"), Elliott International, L.P., a Cayman Islands limited partnership ("Elliott International"), and Elliott International Capital Advisors Inc., a Delaware corporation ("EICA" and collectively with Elliott and Elliott International, the "Reporting Persons"). Paul E. Singer ("Singer"), Elliott Capital Advisors, L.P., a Delaware limited partnership ("Capital Advisors"), which is controlled by Singer, and Elliott Special GP, LLC, a Delaware limited liability company ("Special GP"), which is controlled by Singer, are the general partners of Elliott.  Hambledon, Inc., a Cayman Islands corporation ("Hambledon"), which is also controlled by Singer, is the sole general partner of Elliott International. EICA is the investment manager for Elliott International.  EICA expressly disclaims equitable ownership of and pecuniary interest in any shares of Common Stock.

ELLIOTT

The business address of Elliott is 40 West 57th Street, New York, New York 10019.

The principal business of Elliott is to purchase, sell, trade and invest in securities.

SINGER

Singer's business address is 40 West 57th Street, New York, New York 10019.

Singer's principal business is to serve as a general partner of Elliott and Capital Advisors, as the president of EICA, and as a managing member of Special GP.

CAPITAL ADVISORS

The business address of Capital Advisors is 40 West 57th Street, New York, New York 10019.

The principal business of Capital Advisors is the furnishing of investment advisory services.  Capital Advisors also serves as a managing member of Special GP.

The names, business addresses, and present principal occupation or employment of the general partners of Capital Advisors are as follows:

NAME	ADDRESS	OCCUPATION
Paul E. Singer	40 West 57th St. New York, New York 10019	General partner of Elliott and Capital Advisors; President of EICA; and a managing member of Special GP
Braxton Associates, Inc.	40 West 57th St. New York, New York 10019	The principal business of Braxton Associates, Inc. is serving as general partner of Capital Advisors
Elliott Asset Management LLC	40 West 57th St. New York, New York 10019	General Partner of Capital Advisors

CUSIP No. 58502B106 Schedule 13D Page 6 of 11 Pages

The name, business address, and present principal occupation or employment of the sole director and executive officer of Braxton Associates, Inc. are as follows:

NAME	ADDRESS	OCCUPATION
Paul E. Singer	40 West 57th St. New York, New York 10019	General partner of Elliott and Capital Advisors and President of EICA

ELLIOTT SPECIAL GP, LLC

The business address of Special GP is 40 West 57th Street, New York, New York 10019.

The principal business of Special GP is serving as a general partner of Elliott.

The names, business address, and present principal occupation or employment of the managing members of Special GP are as follows:

NAME	ADDRESS	OCCUPATION
Paul E. Singer	40 West 57th St. New York, New York 10019	General partner of Elliott and Capital Advisors; President of EICA; and a managing member of Special GP
Braxton Associates, Inc.	40 West 57th St. New York, New York 10019	The principal business of Braxton Associates, Inc. is serving as general partner of Capital Advisors
Elliott Asset Management LLC	40 West 57th St. New York, New York 10019	General Partner of Capital Advisors

ELLIOTT INTERNATIONAL

The business address of Elliott International is c/o Maples & Calder, P.O. Box 309, Ugland House, South Church Street, George Town, Cayman Islands, British West Indies.

The principal business of Elliott International is to purchase, sell, trade and invest in securities.

The name, business address, and present principal occupation or employment of the general partner of Elliott International is as follows:

NAME	ADDRESS	OCCUPATION
Hambledon, Inc.	c/o Maples & Calder P.O. Box 309 Ugland House South Church Street George Town, Cayman Islands British West Indies	General partner of Elliott International

CUSIP No. 58502B106 Schedule 13D Page 7 of 11 Pages

HAMBLEDON

The name, business address, and present principal occupation or employment of the sole director and executive officer of Hambledon are as follows:

NAME	ADDRESS	OCCUPATION
Paul E. Singer	40 West 57th St. New York, New York 10019	General partner of Elliott and Capital Advisors and President of EICA; and a managing member of Special GP

EICA

The business address of EICA is 40 West 57th Street New York, New York 10019.

The principal business of EICA is to act as investment manager for Elliott International.

The name, business address, and present principal occupation or employment of the sole director and executive officer of EICA is as follows:

NAME	ADDRESS	OCCUPATION
Paul E. Singer	40 West 57th St. New York, New York 10019	General partner of Elliott and Capital Advisors and President of EICA; and a managing member of Special GP

(d) and (e) During the last five years, none of the persons or entities listed above  has been (i) convicted in a criminal proceeding (excluding traffic violations or similar misdemeanors); or (ii) a party to a civil proceeding of a judicial or administrative body of competent jurisdiction and as a result of such proceeding 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) Singer is a citizen of the United States of America.

Item 3.	SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION
Elliott Working Capital		The aggregate purchase price of the shares of Common Stock directly owned by Elliott is approximately $27,166,213.40.
Elliott International Working Capital		The aggregate purchase price of the shares of Common Stock directly owned by Elliott International is approximately $57,728,200.34.
The Reporting Persons may effect purchases of shares of Common Stock through margin accounts maintained for them with prime brokers, which extend margin credit as and when required to open or carry positions in their margin accounts, subject to applicable federal margin regulations, stock exchange rules and such firms' credit policies. Positions in shares of Common Stock may be held in margin accounts and may be pledged as collateral security for the repayment of debit balances in such accounts. Since other securities may be held in such margin accounts, it may not be possible to determine the amounts, if any, of margin used to purchase shares of Common Stock.

CUSIP No. 58502B106 Schedule 13D Page 8 of 11 Pages

Item 4.

PURPOSE OF TRANSACTION

The Reporting Persons believe that the securities of the Issuer are undervalued and seek to engage in a constructive dialogue with the Issuer's management and Board of Directors regarding strategic options and operational opportunities to maximize shareholder value. The Reporting Persons believe that there is substantial upside from the Issuer's unaffected share price level of $43.37 per share, the closing price of the Issuer's shares on November 3, 2017, the last trading day prior to the Reporting Persons' increased share accumulation and prior to news reports of private equity interest in the space. Depending upon overall market conditions, other investment opportunities available to the Reporting Persons, and the availability of securities of the Issuer at prices that would make the purchase or sale of such securities desirable, the Reporting Persons may endeavor (i) to increase or decrease their respective positions in the Issuer through, among other things, the purchase or sale of securities of the Issuer on the open market or in private transactions, including through a trading plan created under Rule 10b5-1(c) or otherwise, on such terms and at such times as the Reporting Persons may deem advisable and/or (ii) to enter into transactions that increase or hedge their economic exposure to the Common Stock without affecting their beneficial ownership of shares of Common Stock. No Reporting Person has any present plan or proposal which would relate to or result in any of the matters set forth in subparagraphs (a) - (j) of Item 4 of Schedule 13D except as set forth herein or such as would occur upon or in connection with completion of, or following, any of the actions discussed herein. The Reporting Persons may consider, explore and/or develop plans and/or make proposals with respect to, or with respect to potential changes in, the operations, management, the certificate of incorporation and bylaws, Board composition, ownership, capital or corporate structure, capital allocation, dividend policy, strategy and plans of the Issuer, potential strategic transactions involving the Issuer or certain of the Issuer's businesses or assets, or may change their intention with respect to any and all matters referred to in Item 4. The Reporting Persons intend to communicate with the Issuer's management and Board about a broad range of strategic and operational matters, including, without limitation, a sale of the Issuer or certain of its businesses or assets, in which the Reporting Persons may participate, as a means of enhancing shareholder value. The Reporting Persons intend to review their investment in the Issuer on a continuing basis and may from time to time in the future express their views to and/or meet with management, the Board, other shareholders or third parties, including, potential acquirers, service providers, advisers, and financing sources, and/or formulate plans or proposals regarding the Issuer, its assets or its securities. The Reporting Persons may exchange information with any such persons pursuant to appropriate confidentiality or similar agreements. Such proposals or plans may include one or more plans that relate to or would result in any of the actions set forth in subparagraphs (a) - (j) of Item 4 of Schedule 13D.

Item 5. INTEREST IN SECURITIES OF THE ISSUER

(a)       As of the date hereof, Elliott, Elliott International and EICA collectively have combined economic exposure in the Issuer of approximately 7.0% of the shares of Common Stock outstanding.

The aggregate percentage of Common Stock reported owned by each person named herein is based upon 93,655,243 shares of Common Stock outstanding, which is the total number of shares of Common Stock outstanding as of October 27, 2017 as reported in the Issuer's Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2017, filed with the Securities and Exchange Commission (the "SEC") on November 1, 2017.

CUSIP No. 58502B106 Schedule 13D Page 9 of 11 Pages

As of the date hereof, Elliott itself and through The Liverpool Limited Partnership, a Bermuda limited partnership and a wholly-owned subsidiary of Elliott ("Liverpool") beneficially owned 608,000 shares of Common Stock, constituting 0.7% of the shares of Common Stock outstanding.

As of the date hereof, Elliott International beneficially owned 1,292,000 shares of Common Stock, constituting 1.4% of the shares of Common Stock outstanding. EICA, as the investment manager of Elliott International may be deemed to beneficially own the 1,292,000 shares of Common Stock beneficially owned by Elliott International, constituting 1.4% of the shares of Common Stock outstanding.

Collectively, Elliott, Elliott International and EICA beneficially own 1,900,000 shares of Common Stock, constituting approximately 2.0% of the shares of Common Stock outstanding.

Collectively, Elliott, Elliott International and EICA have economic exposure comparable to approximately 5.0% of the shares of Common Stock outstanding pursuant to the Derivative Agreements, as disclosed in Item 6.

(b)       Elliott has the power to vote or direct the vote of, and to dispose or direct the disposition of the shares of Common Stock owned directly by it.

Elliott International has the shared power with EICA to vote or direct the vote of, and to dispose or direct the disposition of, the shares of Common Stock owned directly by Elliott International. Information regarding each of Elliott International and EICA is set forth in Item 2 of this Schedule 13D and is expressly incorporated by reference herein.

(c)       The transactions effected by the Reporting Persons during the past 60 days are set forth on Schedule 1 attached hereto.

(d)       No person other than Elliott has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the shares of Common Stock beneficially owned by Elliott.

No person other than Elliott International and EICA has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the shares of Common Stock beneficially owned by Elliott International and EICA.

(e)       Not applicable.

Item 6. CONTRACTS, ARRANGEMENTS, UNDERSTANDINGS OR RELATIONSHIPS WITH RESPECT TO SECURITIES OF THE ISSUER

Elliott, through Liverpool, and Elliott International have entered into notional principal amount derivative agreements (the "Derivative Agreements") in the form of cash settled swaps with respect to 1,495,999 and 3,179,001 shares of Common Stock of the Issuer, respectively (representing economic exposure comparable to 1.6% and 3.4% of the shares of Common Stock of the Issuer, respectively). Collectively, the Derivative Agreements held by the Reporting Persons represent economic exposure comparable to an interest in approximately 5.0% of the shares of Common Stock. The Derivative Agreements provide Elliott and Elliott International with economic results that are comparable to the economic results of ownership but do not provide them with the power to vote or direct the voting or dispose of or direct the disposition of the shares that are referenced in the Derivative Agreements (such shares, the "Subject Shares"). The Reporting Persons disclaim beneficial ownership in the Subject Shares. The counterparties to the Derivative Agreements are unaffiliated third party financial institutions.

CUSIP No. 58502B106 Schedule 13D Page 10 of 11 Pages

On November 16, 2017 Elliott, Elliott International and EICA entered into a Joint Filing Agreement (the "Joint Filing Agreement") in which the parties agreed to the joint filing on behalf of each of them of statements on Schedule 13D with respect to the securities of the Issuer to the extent required by applicable law. The Joint Filing Agreement is attached as Exhibit 99.1 hereto and is incorporated herein by reference.

Except as described above in this Item 6, none of the Reporting Persons has any contracts, arrangements, understandings or relationships with respect to the securities of the Issuer.

Item 7.	EXHIBITS
Exhibit		Description
Exhibit 99.1 -		Joint Filing Agreement
Schedule 1 -		Transactions of the Reporting Persons Effected During the Past 60 Days

CUSIP No. 58502B106 Schedule 13D Page 11 of 11 Pages

SIGNATURES

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

DATE: November 16, 2017

ELLIOTT ASSOCIATES, L.P.

By: Elliott Capital Advisors, L.P., as General Partner

By: Braxton Associates, Inc., as General Partner

/s/ Elliot Greenberg

Name: Elliot Greenberg

Title: Vice President

ELLIOTT INTERNATIONAL, L.P.

By: Elliott International Capital Advisors Inc., as Attorney-in-Fact

/s/ Elliot Greenberg

Name: Elliot Greenberg

Title: Vice President

ELLIOTT INTERNATIONAL CAPITAL ADVISORS INC.

/s/ Elliot Greenberg

Name: Elliot Greenberg

Title: Vice President