SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 SCHEDULE 13G* (Rule 13d-102) INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO RULES 13d-1(b), (c), AND (d) AND AMENDMENTS THERETO FILED PURSUANT TO RULE 13d-2 (AMENDMENT NO. )* MainStay DefinedTerm Municipal Opportunities Fund -------------------------------------------------------------------------------- (Name of Issuer) Fixed Rate Municipal Term Preferred Shares, Series A -------------------------------------------------------------------------------- (Title of Class of Securities) 56064K-20-9 -------------------------------------------------------- (CUSIP Number) October 4, 2012 -------------------------------------------------------------------------------- (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule is filed: /X/ Rule 13d-1(b) / / Rule 13d-1(c) / / Rule 13d-1(d) *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 the disclosures provided in a prior cover page. The information required in 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). Page 1 of 8 Pages 13G CUSIP NO. 56064K-20-9 Page 2 of 8 Pages ------------------------------------------------------------------------------- (1) NAMES OF REPORTING PERSONS Citibank N.A. ------------------------------------------------------------------------------- (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) / / (b) / / ------------------------------------------------------------------------------- (3) SEC USE ONLY ------------------------------------------------------------------------------- (4) CITIZENSHIP OR PLACE OF ORGANIZATION Delaware ------------------------------------------------------------------------------- NUMBER OF (5) SOLE VOTING POWER SHARES ---------------------------------------------------- BENEFICIALLY (6) SHARED VOTING POWER 350 OWNED BY ---------------------------------------------------- EACH (7) SOLE DISPOSITIVE POWER 350 REPORTING ---------------------------------------------------- PERSON (8) SHARED DISPOSITIVE POWER WITH: ------------------------------------------------------------------------------- (9) AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 350 ------------------------------------------------------------------------------- (10) CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) / / ------------------------------------------------------------------------------- (11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 100% ------------------------------------------------------------------------------- (12) TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) BK ------------------------------------------------------------------------------- 13G CUSIP NO. 56064K-20-9 Page 3 of 8 Pages ------------------------------------------------------------------------------- (1) NAMES OF REPORTING PERSONS Citicorp ------------------------------------------------------------------------------- (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) / / (b) / / ------------------------------------------------------------------------------- (3) SEC USE ONLY ------------------------------------------------------------------------------- (4) CITIZENSHIP OR PLACE OF ORGANIZATION Delaware ------------------------------------------------------------------------------- NUMBER OF (5) SOLE VOTING POWER SHARES ---------------------------------------------------- BENEFICIALLY (6) SHARED VOTING POWER 350 OWNED BY ---------------------------------------------------- EACH (7) SOLE DISPOSITIVE POWER 350 REPORTING ---------------------------------------------------- PERSON (8) SHARED DISPOSITIVE POWER WITH: ------------------------------------------------------------------------------- (9) AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 350 ------------------------------------------------------------------------------- (10) CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) / / ------------------------------------------------------------------------------- (11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 100% ------------------------------------------------------------------------------- (12) TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) HC ------------------------------------------------------------------------------- 13G CUSIP NO. 56064K-20-9 Page 4 of 8 Pages ------------------------------------------------------------------------------- (1) NAMES OF REPORTING PERSONS Citigroup Inc. ------------------------------------------------------------------------------- (2) CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) / / (b) / / ------------------------------------------------------------------------------- (3) SEC USE ONLY ------------------------------------------------------------------------------- (4) CITIZENSHIP OR PLACE OF ORGANIZATION Delaware ------------------------------------------------------------------------------- NUMBER OF (5) SOLE VOTING POWER SHARES ---------------------------------------------------- BENEFICIALLY (6) SHARED VOTING POWER 350* OWNED BY ---------------------------------------------------- EACH (7) SOLE DISPOSITIVE POWER 350* REPORTING ---------------------------------------------------- PERSON (8) SHARED DISPOSITIVE POWER WITH: ------------------------------------------------------------------------------- (9) AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 350* ------------------------------------------------------------------------------- (10) CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) / / ------------------------------------------------------------------------------- (11) PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 100%* ------------------------------------------------------------------------------- (12) TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) HC ------------------------------------------------------------------------------- * Includes shares held by the other reporting persons. Item 1(a). Name of Issuer: MainStay DefinedTerm Municipal Opportunities Fund Item 1(b). Address of Issuer's Principal Executive Offices: 51 Madison Avenue New York, NY 10010 Item 2(a). Name of Person Filing: Citibank, N.A. ("Citibank") Citicorp Citigroup Inc. ("Citigroup") Item 2(b). Address of the Principal Business Office or, if none, Residence: The address of the principal business office of Citibank, Citicorp and Citigroup is: 399 Park Avenue New York, NY 10022 Item 2(c). Citizenship: Citibank is a national banking association Citicorp and Citigroup are Dalaware corporations. Item 2(d). Title of Class of Securities: Fixed Rate Municipal Term Preferred Shares, Series A Item 2(e). CUSIP Number: 56064K-20-9 Page 5 of 8 Pages Item 3. If This Statement Is Filed Pursuant to Sections 240.13d-1(b) or 240.13d-2(b) or (c), Check Whether the Person Filing Is a(n): (a) [ ] Broker or dealer registered under Section 15 of the Act (15 U.S.C. 78o); (b) [X] Bank as defined in Section 3(a)(6) of the Act (15 U.S.C. 78c); (c) [ ] Insurance company as defined in Section 3(a)(19) of the Act (15 U.S.C. 78c); (d) [ ] Investment company registered under Section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8); (e) [ ] Investment adviser in accordance with Section 240.13d-1(b)(1)(ii)(E); (f) [ ] Employee benefit plan or endowment fund in accordance with Section 240.13d-1(b)(1)(ii)(F); (g) [X] Parent holding company or control person in accordance with Section 240.13d-1(b)(1)(ii)(G); (h) [ ] Savings association as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813); (i) [ ] Church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3); (j) [ ] A non-U.S. institution in accordance with Section 240.13d-1(b)(1)(ii)(J); (k) [ ] Group, in accordance with Section 240.13d-1(b)(1)(ii)(K). If filing as a non-U.S. institution in accordance with Section 240.13d-1(b)(1)(ii)(J), please specify the type of institution: ____________________________ . Item 4. Ownership. (as of October 4, 2012) (a) Amount beneficially owned: See item 9 of cover pages (b) Percent of class: See item 11 of cover pages (c) Number of shares as to which the person has: (i) Sole power to vote or to direct the vote: (ii) Shared power to vote or to direct the vote: (iii) Sole power to dispose or to direct the disposition of: (iv) Shared power to dispose or to direct the disposition of: See Items 5-8 of cover pages Page 6 of 8 Pages Item 5. Ownership of Five Percent or Less of a Class. If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following [ ]. Item 6. Ownership of More Than Five Percent on Behalf of Another Person. Not Applicable. Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company. Citicorp is the sole stockholder of Citibank. Citigroup is the sole stockholder of Citicorp. Item 8. Identification and Classification of Members of the Group. Not Applicable. Item 9. Notice of Dissolution of Group. Not Applicable. Page 7 of 8 Pages Item 10. Certification. By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect. SIGNATURE. After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct. Dated: Octtober 10, 2012 CITIBANK N.A. By: /s/ Ali L. Karshan -------------------------------------------- Name: Ali L. Karshan Title: Assistant Secretary CITICORP By: /s/ Ali L. Karshan -------------------------------------------- Name: Ali L. Karshan Title: Assistant Secretary CITIGROUP INC. By: /s/ Ali L. Karshan -------------------------------------------- Name: Ali L. Karshan Title: Assistant Secretary Page 8 of 8 Pages EXHIBIT INDEX TO SCHEDULE 13G ----------------------------- EXHIBIT 1 --------- Agreement among Citibank, Citicorp and Citigroup as to joint filing of Schedule 13G