# EDGAR Filing Document

**Accession Number:** 0001266585
**File Stem:** 0001999371-26-012657
**Filing Date:** 2026-6
**Character Count:** 65996
**Document Hash:** 849f09c67de066b7a8e7bc2d7d43f68f
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001999371-26-012657.hdr.sgml**: 20260611

**ACCESSION NUMBER**: 0001999371-26-012657

**CONFORMED SUBMISSION TYPE**: POS EX

**PUBLIC DOCUMENT COUNT**: 5

**FILED AS OF DATE**: 20260611

**DATE AS OF CHANGE**: 20260611

**EFFECTIVENESS DATE**: 20260611

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** NUVEEN MUNICIPAL HIGH INCOME OPPORTUNITY FUND
- **CENTRAL INDEX KEY:** 0001266585

**ORGANIZATION NAME:**
- **EIN:** 000000000
- **STATE OF INCORPORATION:** MA

**FILING VALUES:**
- **FORM TYPE:** POS EX
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-290590
- **FILM NUMBER:** 261083989

**BUSINESS ADDRESS:**
- **STREET 1:** 333 W WACKER DRIVE
- **CITY:** CHICAGO
- **STATE:** IL
- **ZIP:** 60606
- **BUSINESS PHONE:** 312 917 8146

**MAIL ADDRESS:**
- **STREET 1:** 333 WEST WACKER DRIVE
- **CITY:** CHICAGO
- **STATE:** IL
- **ZIP:** 60606

**As filed with the Securities and Exchange Commission on June 11, 2026**

File No. 333-290590

**UNITED STATES<br> SECURITIES AND EXCHANGE COMMISSION** **<br> Washington, D.C. 20549**

------

**FORM N-14**

**REGISTRATION STATEMENT<br> *UNDER<br> THE SECURITIES ACT OF 1933***

☐ Pre-Effective Amendment No. __

☒ Post-Effective Amendment No. 1

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**Nuveen Municipal High Income<br> Opportunity Fund**

(Exact Name of Registrant as Specified in Charter)

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**333 West Wacker Drive<br> Chicago, Illinois 60606**<br> (Address of Principal Executive Offices: Number, Street, City, State, Zip Code)

<br> **(800) 257-8787**<br> (Area Code and Telephone Number)

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**Mark L. Winget<br> Vice President and Secretary<br> Nuveen Investments<br> 333 West Wacker Drive<br> Chicago, Illinois 60606**<br> (Name and Address of Agent for Service)

------

<br> Copies to:

---

| | |
|:---|:---|
| **Deborah Bielicke Eades**<br> **Vedder Price P.C.**<br> **222 North LaSalle Street**<br> **Chicago, Illinois 60601** | **Eric F. Fess**<br> **Chapman and Cutler LLP**<br> **320 South Canal Street, 27th Floor**<br> **Chicago, Illinois 60606** |

---

**EXPLANATORY NOTE**

The Joint Proxy Statement/Prospectus and Statement of Additional Information, each in the form filed on [December 18, 2025](https://www.sec.gov/Archives/edgar/data/1266585/000199937125020575/nuveen-424b3_121625.htm), pursuant to Rule 424 of the General Rules and Regulations under the Securities Act of 1933, as amended (File No. 333-290590), are incorporated herein by reference.

This amendment is being filed for the sole purpose of adding to Part C of the Registration Statement the executed opinions and consents of Vedder Price P.C. and Stradley Ronon Stevens & Young, LLP, supporting the tax matters discussed in the Joint Proxy Statement/Prospectus as Exhibit 12(a) and Exhibit 12(b).

**PART C<br> OTHER INFORMATION**

**Item 15. Indemnification**

Section 4 of Article XII of Registrant's Declaration of Trust, as amended, provides as follows:

Subject to the exceptions and limitations contained in this Section 4, every person who is, or has been, a Trustee, officer, employee or agent of the Trust, including persons who serve at the request of the Trust as directors, trustees, officers, employees or agents of another organization in which the Trust has an interest as a shareholder, creditor or otherwise (hereinafter referred to as a "Covered Person"), shall be indemnified by the Trust to the fullest extent permitted by law against liability and against all expenses reasonably incurred or paid by him in connection with any claim, action, suit or proceeding in which he becomes involved as a party or otherwise by virtue of his being or having been such a Trustee, director, officer, employee or agent and against amounts paid or incurred by him in settlement thereof.

No indemnification shall be provided hereunder to a Covered Person:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) against any liability to the Trust or its Shareholders by reason of a final adjudication by the court or other body before which the proceeding was brought that he engaged in willful misfeasance, bad faith, gross negligence or reckless disregard of the duties involved in the conduct of his office;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b) with respect to any matter as to which he shall have been finally adjudicated not to have acted in good faith in the reasonable belief that his action was in the best interests of the Trust; or

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(c) in the event of a settlement or other disposition not involving a final adjudication (as provided in paragraph (a) or (b)) and resulting in a payment by a Covered Person, unless there has been either a determination that such Covered Person did not engage in willful misfeasance, bad faith, gross negligence or reckless disregard of the duties involved in the conduct of his office by the court or other body approving the settlement or other disposition or a reasonable determination, based on a review of readily available facts (as opposed to a full trial-type inquiry), that he did not engage in such conduct:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(i) by a vote of a majority of the Disinterested Trustees acting on the matter (provided that a majority of the Disinterested Trustees then in office act on the matter); or

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(ii) by written opinion of independent legal counsel.

The rights of indemnification herein provided may be insured against by policies maintained by the Trust, shall be severable, shall not affect any other rights to which any Covered Person may now or hereafter be entitled, shall continue as to a person who has ceased to be such a Covered Person and shall inure to the benefit of the heirs, executors and administrators of such a person. Nothing contained herein shall affect any rights to indemnification to which Trust personnel other than Covered Persons may be entitled by contract or otherwise under law.

Expenses of preparation and presentation of a defense to any claim, action, suit or proceeding subject to a claim for indemnification under this Section 4 shall be advanced by the Trust prior to final disposition thereof upon receipt of an undertaking by or on behalf of the recipient to repay such amount if it is ultimately determined that he is not entitled to indemnification under this Section 4, provided that either:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(a) such undertaking is secured by a surety bond or some other appropriate security or the Trust shall be insured against losses arising out of any such advances; or

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(b) a majority of the Disinterested Trustees acting on the matter (provided that a majority of the Disinterested Trustees then in office act on the matter) or independent legal counsel in a written opinion shall determine, based upon a review of the readily available facts (as opposed to a full trial-type inquiry), that there is reason to believe that the recipient ultimately will be found entitled to indemnification.

As used in this Section 4, a "Disinterested Trustee" is one (x) who is not an Interested Person of the Trust (including, as such Disinterested Trustee, anyone who has been exempted from being an Interested Person by any rule, regulation or order of the Commission), and (y) against whom none of such actions, suits or other proceedings or another action, suit or other proceeding on the same or similar grounds is then or has been pending.

As used in this Section 4, the words "claim," "action," "suit" or "proceeding" shall apply to all claims, actions, suits, proceedings (civil, criminal, administrative or other, including appeals), actual or threatened; and the word "liability" and "expenses" shall include without limitation, attorneys' fees, costs, judgments, amounts paid in settlement, fines, penalties and other liabilities.

The trustees and officers of the Registrant are covered by joint errors and omissions insurance policies against liability and expenses of claims of wrongful acts arising out of their position with the Registrant and other Nuveen funds, subject to such policies' coverage limits, exclusions and deductibles.

Insofar as the indemnification for liabilities arising under the Securities Act of 1933, as amended, (the "1933 Act") may be permitted to the officers, trustees or controlling persons of the Registrant pursuant to the Declaration of Trust of the Registrant or otherwise, the Registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the 1933 Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by an officer or trustee or controlling person of the Registrant in the successful defense of any action, suit or proceeding) is asserted by such officer, trustee or controlling person in connection with the securities being registered, the Registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question of whether such indemnification by it is against public policy as expressed in the 1933 Act and will be governed by the final adjudication of such issue.

**Item 16. Exhibits**

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| | |
|:---|:---|
| (1) | [Amended and Restated Declaration of Trust dated October 15, 2003](http://www.sec.gov/Archives/edgar/data/1266585/000119312503063602/dex99a.txt).(1) |
| (2) | [Amended and Restated By-Laws of Registrant, dated February 28, 2024](https://www.sec.gov/Archives/edgar/data/1266585/000119312524063442/d777056dex99b.htm).(2) |
| (3) | Not applicable. |
| (4) | [Form of Agreement and Plan of Merger as Appendix A to the Joint Proxy Statement/Prospectus constituting Part A of the Registration Statement](https://www.sec.gov/Archives/edgar/data/1266585/000199937125020432/nuveen-n148ca_121625.htm).(24) |
| (5) | Not applicable. |
| (6)(a) | [Investment Management Agreement, dated October 1, 2014](https://www.sec.gov/Archives/edgar/data/1266585/000119312515058270/d864533dex99g1.htm).(3) |
| (6)(b) | [Continuance of Investment Management Agreement, dated May 1, 2025](https://www.sec.gov/Archives/edgar/data/1635073/000119312525166330/d18411dex99d5.htm).(4) |
| (6)(c) | [Investment Sub-Advisory Agreement, dated October 1, 2014.](https://www.sec.gov/Archives/edgar/data/1266585/000119312515058270/d864533dex99g2.htm)(3) |
| (6)(d) | [Notice of Continuance of Investment Sub-Advisory Agreement, dated May 1, 2025](https://www.sec.gov/Archives/edgar/data/1635073/000119312525166330/d18411dex99d15.htm).(4) |
| (7)(a) | [Distribution Agreement between Registrant and Nuveen Securities, LLC, dated May 29, 2012](https://www.sec.gov/Archives/edgar/data/1266585/000119312512258522/d206307dex99h1.htm).(5) |
| (7)(b) | [Dealer Agreement between Nuveen Securities, LLC and UBS Securities, LLC, dated May 29, 2012](https://www.sec.gov/Archives/edgar/data/1266585/000119312512258522/d206307dex99h2.htm).(5) |
| (7)(c) | [Distribution Agreement Relating to At-the-Market Offerings between Registrant and Nuveen Securities, LLC, dated March 4, 2013](https://www.sec.gov/Archives/edgar/data/1266585/000119312513101032/d499644dex99h5.htm).(6) |
| (7)(d) | [Dealer Agreement Relating to At-the-Market Offerings between Nuveen Securities, LLC and USB Securities, LLC, dated March 4, 2013](https://www.sec.gov/Archives/edgar/data/1266585/000119312513101032/d499644dex99h6.htm).(6) |
| (7)(e) | [Distribution Agreement Relating to At-the-Market Offerings between the Registrant and Nuveen Securities, LLC, dated July 18, 2016](https://www.sec.gov/Archives/edgar/data/1266585/000119312516707574/d160898dex99h7.htm).(7) |
| (7)(f) | [Dealer Agreement Relating to At-the-Market Offerings between the Nuveen Securities, LLC and UBS Securities, LLC, dated July 18, 2016](https://www.sec.gov/Archives/edgar/data/1266585/000119312516707574/d160898dex99h8.htm).(7) |
| (7)(g) | [Distribution Agreement Relating to At-the-Market Offerings between Registrant and Nuveen Securities, LLC, dated August 24, 2017](https://www.sec.gov/Archives/edgar/data/1266585/000119312517285298/d434481dex99h9.htm).(8) |
| (7)(h) | [Dealer Agreement Relating to At-the-Market Offerings between Nuveen Securities and UBS Securities, LLC, dated September 14, 2017](https://www.sec.gov/Archives/edgar/data/1266585/000119312517285298/d434481dex99h10.htm).(8) |
| (7)(i) | [Distribution Agreement Relating to At-the-Market Offerings between Registrant and Nuveen Securities, LLC, dated February 21, 2020](https://www.sec.gov/Archives/edgar/data/1266585/000119312520052791/d854351dex99h9.htm).(9) |
| (7)(j) | [Dealer Agreement Relating to At-the-Market Offerings between Nuveen Securities and UBS Securities, LLC, dated February 27, 2020](https://www.sec.gov/Archives/edgar/data/1266585/000119312520059121/d854351dex99h10.htm).(10) |
| (7)(k) | [Distribution Agreement Relating to At-the-Market Offerings between Registrant and Nuveen Securities, LLC, dated March 5, 2021](https://www.sec.gov/Archives/edgar/data/1266585/000119312521072653/d128847dex99h11.htm).(11) |
| (7)(l) | [Dealer Agreement Relating to At-the-Market Offerings between Nuveen Securities and UBS Securities, LLC, dated March 5, 2021](https://www.sec.gov/Archives/edgar/data/1266585/000119312521072653/d128847dex99h12.htm).(11) |
| (7)(m) | [Distribution Agreement Relating to At-the-Market Offerings between Registrant and Nuveen Securities, LLC, dated December 16, 2021](https://www.sec.gov/Archives/edgar/data/1266585/000119312521361340/d271097dex99h13.htm).(12) |

---

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| | |
|:---|:---|
| (7)(n) | [Dealer Agreement Relating to At-the-Market Offerings between Nuveen Securities and UBS Securities, LLC, dated December 17, 2021](https://www.sec.gov/Archives/edgar/data/1266585/000119312521361340/d271097dex99h14.htm).(12) |
| (8)(a) | [Nuveen Fund Board Voluntary Deferred Compensation Plan for Independent Directors and Trustees, effective as of November 1, 2021](https://www.sec.gov/Archives/edgar/data/1777482/000119312522206173/d264069dex99i2.htm).(13) |
| (8)(b) | [Nuveen Fund Board Voluntary Deferred Compensation Plan for Independent Directors and Trustees, effective as of November 1, 2021, as amended July 1, 2023](https://www.sec.gov/Archives/edgar/data/1777482/000119312523197735/d408388dex99i3.htm).(14) |
| (9)(a) | [Amended and Restated Master Custodian Agreement between Registrant and State Street Bank and Trust Company, dated July 15, 2015](https://www.sec.gov/Archives/edgar/data/1266585/000119312516611328/d160898dex99j1.htm).(15) |
| (9)(b) | [Amendment and revised Appendix A to Amended and Restated Master Custodian Agreement, dated July 31, 2020](https://www.sec.gov/Archives/edgar/data/1450445/000119312520236529/d99489dex99j2.htm).(16) |
| (9)(c) | [Amendment and revised Appendix A, effective September 8, 2022, to the Amended and Restated Master Custodian Agreement](https://www.sec.gov/Archives/edgar/data/1380786/000119312522314076/d403340dex99g3.htm).(17) |
| (10) | Not applicable. |
| (11) | [Opinion and Consent of Counsel](https://www.sec.gov/Archives/edgar/data/1266585/000199937125018025/ex99-11.htm).(18) |
| (12)(a) | [Opinion and Consent of Vedder Price P.C. supporting the tax matters discussed in the Joint Proxy Statement/Prospectus](ex99-12a.htm), is filed herewith. |
| (12)(b) | [Opinion and Consent of Stradley Ronon Stevens & Young, LLP supporting the tax matters discussed in the Joint Proxy Statement/Prospectus](ex99-12b.htm), is filed herewith. |
| (13)(a) | [Transfer Agency and Service Agreement, dated June 15, 2017 between Registrant and Computershare Inc. and Computershare Trust Company, N.A.](https://www.sec.gov/Archives/edgar/data/1266585/000119312517264622/d434481dex99k1.htm)(19) |
| (13)(b) | [Amendment and Schedule A to Transfer Agency and Service Agreement, dated September 7, 2017](https://www.sec.gov/Archives/edgar/data/1266585/000119312519104006/d622713dex99k2.htm)<u>.</u>(20) |
| (13)(c) | [Second Amendment and updated Schedule A, dated February 26, 2018, to the Transfer Agency and Service Agreement dated June 15, 2017 between the Registrant and Computershare Inc. and Computershare Trust Company, N.A.](https://www.sec.gov/Archives/edgar/data/830271/000119312520249182/d883410dex99k3.htm)(21) |
| (13)(d) | [Third Amendment and updated Schedule A, dated May 11, 2020 to the Transfer Agency and Service Agreement dated June 15, 2017 between the Registrant and Computershare Inc. and Computershare Trust Company, N.A.](https://www.sec.gov/Archives/edgar/data/1266585/000119312521071766/d128847dex99k4.htm)(21) |
| (13)(e) | [Amended and Restated Schedule A, effective March 28, 2023, to the Transfer Agency and Service Agreement](https://www.sec.gov/Archives/edgar/data/885732/000119312523143216/d422297dex99k5.htm).(22) |
| (13)(f) | [Rule 12d1-4 Investment Agreement between RiverNorth Funds, as Acquiring Funds, and Nuveen CEFs, as Acquired Funds, dated January 19, 2022](https://www.sec.gov/Archives/edgar/data/885732/000119312523143216/d422297dex99k6.htm).(22) |
| (14)(a) | [Consent of PricewaterhouseCoopers LLP, independent registered public accounting firm](https://www.sec.gov/Archives/edgar/data/1266585/000199937125020432/ex99-14a.htm).(24) |
| (14)(b) | [Consent of KPMG LLP, independent registered public accounting firm](https://www.sec.gov/Archives/edgar/data/1266585/000199937125020432/ex99-14b.htm).(24) |
| (15) | Not applicable. |
| (16) | [Powers of Attorney](https://www.sec.gov/Archives/edgar/data/1266585/000199937125014188/ex99-16.htm).(23) |
| (17) | [Form of Proxy appears following the Joint Proxy Statement/Prospectus constituting Part A of the Registration Statement](https://www.sec.gov/Archives/edgar/data/1266585/000199937125020432/nuveen-n148ca_121625.htm).(24) |

---

(18) [Filing Fee Table](https://www.sec.gov/Archives/edgar/data/1266585/000199937125020432/ex99-18.htm) .(24)

(1) Filed on October 17, 2003 as an exhibit to the Registrant's Registration Statement on Form N-2 (File No. 333-109801) and incorporated by reference herein.

(2) Filed on March 8, 2024 as an exhibit to the Registrant's Registration Statement on Form N-2 (File No. 811-21449) and incorporated by reference herein.

(3) Filed on February 23, 2015 as an exhibit to the Registrant's Registration Statement on Form N-2 (File No. 333-187032) and incorporated by reference herein.

(4) Filed on July 28, 2025 as an exhibit to Nushares ETF Trust's Registration Statement on Form N-1A (File No. 333-212032) and incorporated by reference herein.

(5) Filed on June 4, 2012 as an Exhibit to Registrant's Registration Statement on Form N-2 (File No. 333-161462) and incorporated by reference herein.

(6) Filed on March 11, 2013 as an Exhibit to Registrant's Registration Statement on Form N-2 (File No. 333-187032) and incorporated by reference herein.

(7) Filed on September 12, 2016 as an Exhibit to Registrant's Registration Statement on Form N-2 (File No. 333-211793) and incorporated by reference herein.

(8) Filed on September 14, 2017 as an Exhibit to Registrant's Registration Statement on Form N-2 (File No. 333-220101) and incorporated by reference herein.

(9) Filed on February 27, 2020 as an Exhibit to Registrant's Registration Statement on Form N-2 (File No. 333-235960) and incorporated by reference herein.

(10) Filed on March 2, 2020 as an Exhibit to Registrant's Registration Statement on Form N-2 (File No. 333-235960) and incorporated by reference herein.

(11) Filed on March 8, 2021 as an Exhibit to Registrant's Registration Statement on Form N-2 (File No. 333-253965) and incorporated by reference herein.

(12) Filed on December 17, 2021 as an Exhibit to Registrant's Registration Statement on Form N-2 (File No. 253965) and incorporated by reference herein.

(13) Filed on July 29, 2022 as an Exhibit to Nuveen Enhanced High Yield Municipal Bond Fund's Registration Statement on Form N-2 (File No. 333-231722) and incorporated by reference herein.

(14) Filed on July 1, 2023 as an Exhibit to Nuveen Enhanced High Yield Municipal Bond Fund's Registration Statement on Form N-2 (File No. 333-231722) and incorporated by reference herein.

(15) Filed on June 6, 2016 as an Exhibit to Registrant's Registration Statement on Form N-2 (File No. 333-211793) and incorporated by reference herein.

(16) Filed on September 1, 2020 as an Exhibit to Nuveen AMT-Free Municipal Value Fund's Registration Statement on Form N-2 (File No. 333-223524) and incorporated by reference herein.

(17) Filed on December 29, 2022 as an Exhibit to Nuveen Investment Trust V's Registration Statement on Form N-1A (File No. 333-138592) and incorporated by reference herein.

(18) Filed on November 17, 2025 as an Exhibit to Registrant's Registration Statement on Form N-14 (File No. 333-2290590) and incorporated by reference herein.

(19) Filed on August 22, 2017 as an Exhibit to Registrant's Registration Statement on Form N-2 (File No. 333-220101) and incorporated by reference herein.

(20) Filed on April 11, 2019 as an Exhibit to Registrant's Registration Statement on Form N-2 (File No. 333-220101) and incorporated by reference herein.

(21) Filed on September 18, 2020 as an Exhibit to Registrant's Registration Statement on Form N-2 (File No. 333-237289) and incorporated by reference herein.

(22) Filed on May 12, 2023 as an Exhibit to Nuveen California Select Tax Free Income Portfolio's Registration Statement on Form N-2 (File No. 333-271871) and incorporated by reference herein.

(23) Filed on September 29, 2025 as an exhibit to the Registrant's Registration Statement on Form N-14 (File No. 333-290590) and incorporated by reference herein.

(24) Filed on December 16, 2025 as an exhibit to the Registrant's Registration Statement on Form N-14 (File No. 333-290590) and incorporated by reference herein.

**Item 17. Undertakings**

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(1) The undersigned Registrant agrees that prior to any public reoffering of the securities registered through the use of a prospectus which is a part of this registration statement by any person or party who is deemed to be an underwriter within the meaning of Rule 145(c) of the Securities Act, the reoffering prospectus will contain the information called for by the applicable registration form for reofferings by persons who may be deemed underwriters, in addition to the information called for by the other items of the applicable form.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(2) The undersigned Registrant agrees that every prospectus that is filed under paragraph (1) above will be filed as a part of an amendment to the registration statement and will not be used until the amendment is effective, and that, in determining any liability under the Securities Act, each post-effective amendment shall be deemed to be a new registration statement for the securities offered therein, and the offering of the securities at that time shall be deemed to be the initial bona fide offering of them.

**SIGNATURES**

As required by the Securities Act of 1933, the Registrant has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized in the City of Chicago and the State of Illinois, on the 10<sup>th</sup> day of June, 2026.

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| | |
|:---|:---|
| Nuveen Municipal High Income Opportunity Fund | Nuveen Municipal High Income Opportunity Fund |
| By: | /s/ Mark L. Winget |
|  | Mark L. Winget |
|  | Vice President and Secretary |

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As required by the Securities Act of 1933, this Registrant's registration statement has been signed by the following persons in the capacities and on the dates indicated:

---

| | | | |
|:---|:---|:---|:---|
| **Signature** | **Capacity** | **Date** | **Date** |
| /s/ David J. Lamb | Chief Administrative Officer |  |  |
| David J. Lamb | (principal executive officer) | June 10, 2026 | June 10, 2026 |
| /s/ Mark Cardella | Vice President and Controller |  |  |
| <br> Mark Cardella | (principal financial and accounting officer) | June 10, 2026 | June 10, 2026 |
|  |  | By: | <u>/s/ Mark L. Winget</u> |
| Robert L. Young\* | Chair of the Board and Trustee |  | &nbsp;&nbsp;&nbsp;&nbsp;Mark L. Winget<br> Attorney-in-Fact<br> June 10, 2026 |
|  | Trustee |  |  |
| Joseph A. Boateng\* |  |  |  |
|  | Trustee |  |  |
| Michael A. Forrester\* |  |  |  |
|  | Trustee |  |  |
| Thomas J. Kenny\* |  |  |  |
|  | Trustee |  |  |
| Amy B.R. Lancellotta\* |  |  |  |
|  | Trustee |  |  |
| Joanne T. Medero\* |  |  |  |
|  | Trustee |  |  |
| Albin F. Moschner\* |  |  |  |
|  | Trustee |  |  |
| John K. Nelson\* |  |  |  |
|  | Trustee |  |  |
| Loren M. Starr\* |  |  |  |
|  | Trustee |  |  |
| Matthew Thornton III\* |  |  |  |

---

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| | |
|:---|:---|
| | Trustee |
| Terence J. Toth\* |  |
| | Trustee |
| Margaret L. Wolff\* |  |

---

\* An original power of attorney authorizing, among others, Mark L. Winget, Kevin J. McCarthy and Mark J. Czarniecki to execute this registration statement, and amendments thereto, for each of the trustees of the Registrant on whose behalf this registration statement is filed, has been executed and is Exhibit (16) which is incorporated by reference to the Registrant's Registration Statement on Form N-14 (File No. 333-290590) filed on December 16, 2025.

**EXHIBIT INDEX**

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| | |
|:---|:---|
| **Exhibit No.** | **Name of Exhibit** |
| (12)(a) | [Opinion and Consent of Vedder Price P.C. supporting the tax matters discussed in the Joint Proxy Statement/Prospectus.](ex99-12a.htm) |
| (12)(b) | [Opinion and Consent of Stradley Ronon Stevens & Young, LLP supporting the tax matters discussed in the Joint Proxy Statement/Prospectus.](ex99-12b.htm) |

---

## Exhibit 99.12

[Nuveen Municipal High Income Opportunity Fund POS EX](nmz-posex_061126.htm)

**Exhibit 99.(12)(a)**

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| | | |
|:---|:---|:---|
| Vedder Price<br> 222 North LaSalle Street<br> Chicago, Illinois 60601 | T: +1 312 609 7500<br> F: +1 312 609 5005<br> vedder.com | ![](ex9912a001.jpg) |

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April 27, 2026

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| | |
|:---|:---|
| Nuveen New Jersey Quality Municipal Income Fund<br> 333 West Wacker Drive<br> Chicago, Illinois 60606<br>| &nbsp;&nbsp; Nuveen Missouri Quality Municipal Income Fund<br> 333 West Wacker Drive<br> Chicago, Illinois 60606<br>|
| Nuveen Pennsylvania Quality Municipal Income Fund<br> 333 West Wacker Drive<br> Chicago, Illinois 60606<br>| &nbsp;&nbsp; Nuveen Municipal High Income Opportunity Fund<br> 333 West Wacker Drive<br> Chicago, Illinois 60606<br>|

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| **Re:** | **Reorganization of Nuveen New Jersey Quality Municipal Income Fund, Nuveen Pennsylvania Quality Municipal Income Fund and Nuveen Missouri Quality Municipal Income Fund into Nuveen Municipal High Income Opportunity Fund** |

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Ladies and Gentlemen:

You have requested our opinion regarding certain U.S. federal income tax consequences of certain transactions undertaken pursuant to the Agreement and Plan of Merger dated as of March 19, 2026 by and among Nuveen New Jersey Quality Municipal Income Fund, a Massachusetts business trust ("New Jersey Municipal"), Nuveen Pennsylvania Quality Municipal Income Fund, a Massachusetts business trust ("Pennsylvania Municipal"), and Nuveen Missouri Quality Municipal Income Fund, a Massachusetts business trust ("Missouri Municipal", and together with New Jersey Municipal and Pennsylvania Municipal, each a "Target Fund" and collectively, the "Target Funds"), Nuveen Municipal High Income Opportunity Fund, a Massachusetts business trust (the "Acquiring Fund"), and NMZ Merger Sub, LLC, a Massachusetts limited liability company and a direct, wholly-owned subsidiary of the Acquiring Fund ("Merger Sub") (the "Plan"). The Target Funds and the Acquiring Fund are each referred to herein as a "Fund" and collectively, as the "Funds."

The Plan contemplates that (i) each Target Fund will merge pursuant to applicable state law with and into Merger Sub with Merger Sub surviving (each a "Merger" and collectively, the "Mergers"), all the common shares of beneficial interest of the Target Fund will be converted into voting common shares of beneficial interest, par value $0.01 per share, of the Acquiring Fund ("Acquiring Fund Shares") and all the issued and outstanding Variable Rate Demand Preferred Shares ("VRDP Shares") of New Jersey Municipal and Pennsylvania Municipal will be converted into newly issued VRDP Shares of the Acquiring Fund, with a par value of $0.01 per share and a liquidation preference of $100,000 per share, having all the various rights, preferences and privileges set forth under the heading "Proposal No. 1 – Merger of Each Target Fund into the Acquiring Fund – Information about the Mergers – Description of VRDP Shares to Be Issued by the Acquiring Fund" in the Proxy Statement (as defined below) (the "Acquiring Fund VRDP Shares") and (ii) as soon as practicable thereafter Merger Sub will completely liquidate into the Acquiring Fund by distributing all its assets to the Acquiring Fund and the Acquiring Fund will assume all the liabilities of Merger Sub in complete liquidation and dissolution of Merger Sub (the "Liquidation"). The Mergers and the Liquidation are referred to collectively herein as the "Reorganization".

Vedder Price P.C. is affiliated with Vedder Price LLP, which operates in England and Wales, Vedder Price (CA), LLP, which operates in California, Vedder Price Pte. Ltd., which operates in Singapore, and Vedder Price (FL) LLP, which operates in Florida.

Chicago \| Dallas \| London \| Los Angeles \| Miami \| New York \| San Francisco \| Singapore \| Washington, DC

Nuveen New Jersey Quality Municipal Income Fund<br> Nuveen Pennsylvania Quality Municipal Income Fund<br> Nuveen Missouri Quality Municipal Income Fund

Nuveen Municipal High Income Opportunity Fund

April 27, 2026

In rendering this opinion, we have examined the Plan and have reviewed and relied upon (i) representations made to us by duly authorized officers of the Funds and Merger Sub in letters dated April 27, 2026 (collectively, the "Representation Letters") and (ii) the opinion of Stradley Ronon Stevens & Young, LLP dated April 27, 2026 regarding the Acquiring Fund VRDP Shares issued in the Mergers being treated as equity of the Acquiring Fund for U.S. federal income tax purposes (the "Equity Opinion"). We have also examined such other agreements, documents, corporate records and other materials as we have deemed necessary in order for us to render the opinions referred to in this letter. In such review and examination, we have assumed the genuineness of all signatures, the legal capacity and authority of the parties who executed such documents, the authenticity of all documents submitted to us as originals, the conformity to originals of all documents submitted to us as copies and the authenticity of the originals of such latter documents.

Our opinion is based, in part, on the assumptions that (i) the Reorganization described herein will occur in accordance with the terms of the Plan (without the waiver or modification of any terms or conditions thereof and without taking into account any amendment thereof that we have not approved) and the facts and representations set forth or referred to in this opinion letter, and that such facts and representations, as well as the facts and representations set forth in the Plan, are true, correct and complete as of the date hereof and will be true, correct and complete as of the date and time of the Closing (as defined in the Plan) (the "Effective Time") through the date and time of the Liquidation, (ii) any representation set forth in the Representation Letters qualified by knowledge, intention, belief, disclaimer of responsibility or any similar qualification is, and will be as of the Effective Time through the date and time of the Liquidation, true, correct and complete without such qualification and (iii) the Acquiring Fund VRDP Shares issued in the Mergers will be treated as equity of the Acquiring Fund for U.S. federal income tax purposes, which assumption is consistent with the Equity Opinion. You have not requested that we undertake, and we have not undertaken, any independent investigation of the accuracy of the facts, representations and assumptions set forth or referred to herein.

For the purposes indicated above, and based upon the facts, assumptions and representations set forth or referred to herein, it is our opinion, with respect to each Merger, that for U.S. federal income tax purposes:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1. The merger of the Target Fund with and into Merger Sub pursuant to applicable state laws will constitute a "reorganization" within the meaning of section 368(a)(1) of the Internal Revenue Code of 1986, as amended (the "Code"), and the Acquiring Fund and the Target Fund will each be a "party to a reorganization," within the meaning of section 368(b) of the Code, with respect to such merger.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2. No gain or loss will be recognized by the Acquiring Fund or Merger Sub upon the merger of the Target Fund with and into Merger Sub pursuant to applicable state laws or upon the liquidation of Merger Sub. (Section 1032(a) of the Code).

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3. No gain or loss will be recognized by the Target Fund upon the merger of the Target Fund with and into Merger Sub pursuant to applicable state laws. (Sections 361(a) and (c) and 357(a) of the Code).

Nuveen New Jersey Quality Municipal Income Fund<br> Nuveen Pennsylvania Quality Municipal Income Fund<br> Nuveen Missouri Quality Municipal Income Fund

Nuveen Municipal High Income Opportunity Fund

April 27, 2026

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;4. No gain or loss will be recognized by the Target Fund's common shareholders upon the conversion of all their shares of the Target Fund solely into Acquiring Fund Shares and by any holders of the VRDP Shares of the Target Fund upon the conversion of all their VRDP shares solely into the Acquiring Fund VRDP Shares in each case in the merger of the Target Fund with and into Merger Sub pursuant to applicable state laws, except to the extent the Target Fund's common shareholders receive cash in lieu of a fractional Acquiring Fund Share. (Section 354(a) of the Code).

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5. The aggregate basis of the Acquiring Fund Shares and/or Acquiring Fund VRDP Shares received by each Target Fund shareholder pursuant to the merger (including any fractional Acquiring Fund Share to which a shareholder would be entitled) will be the same as the aggregate basis of the Target Fund shares that were converted into such Acquiring Fund Shares and/or Acquiring Fund VRDP Shares. (Section 358(a)(1) of the Code).

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6. The holding period of the Acquiring Fund Shares and Acquiring Fund VRDP Shares received by each Target Fund shareholder in the merger (including any fractional Acquiring Fund Share to which a shareholder would be entitled) will include the period during which the shares of the Target Fund that were converted into Acquiring Fund Shares or Acquiring Fund VRDP Shares, as applicable, were held by such shareholder, provided such Target Fund shares were held as capital assets at the Effective Time. (Section 1223(1) of the Code).

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7. The basis of the assets of the Target Fund received by Merger Sub in the merger will be the same as the basis of such assets in the hands of the Target Fund immediately before the Effective Time. (Section 362(b) of the Code).

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8. The holding period of the assets of the Target Fund received by Merger Sub in the merger will include the period during which those assets were held by the Target Fund (except where investment activities of the Acquiring Fund have the effect of reducing or eliminating the holding period with respect to an asset). (Section 1223(2) of the Code).

Notwithstanding anything to the contrary herein, we express no opinion as to the effect of the Reorganization (i) on the Target Funds, the Acquiring Fund, Merger Sub or any Target Fund shareholder with respect to any asset (including without limitation any stock held in a passive foreign investment company as defined in Section 1297(a) of the Code) as to which any gain or loss is required to be recognized under U.S. federal income tax principles (a) at the end of a taxable year or upon the termination thereof, or (b) upon the transfer of such asset regardless of whether such transfer would otherwise be a non-taxable transaction under the Code, (ii) under the alternative minimum tax imposed under Section 55 of the Code on any direct or indirect shareholder of a Target Fund and (iii) any other U.S. federal tax issues (except those set forth above) and all state, local or foreign tax issues of any kind.

**<u>Facts</u>**

Our opinion is based upon the facts, representations and assumptions set forth or referred to above and the following facts and assumptions, any alteration of which could adversely affect our conclusions.

Nuveen New Jersey Quality Municipal Income Fund<br> Nuveen Pennsylvania Quality Municipal Income Fund<br> Nuveen Missouri Quality Municipal Income Fund

Nuveen Municipal High Income Opportunity Fund

April 27, 2026

Each Target Fund has been registered and operated, since it commenced operations, as a closed-end management investment company under the Investment Company Act of 1940, as amended (the "1940 Act"). New Jersey Municipal's common shares are listed and traded on the New York Stock Exchange ("NYSE") under the symbol NXJ, Pennsylvania Municipal's common shares are listed and traded on the NYSE under the symbol NQP, and Missouri Municipal's common shares are listed and traded on the NYSE under the symbol NOM. All the outstanding shares of each Target Fund are treated as equity for U.S. federal income tax purposes. Each Target Fund will have no outstanding shares, other than its common shares and VRDP Shares of each of New Jersey Municipal and Pennsylvania Municipal, at the Effective Time. Prior to the Effective Time, Missouri Municipal redeemed all its issued and outstanding MuniFund Preferred Shares and New Jersey Municipal redeemed Series 1 of its issued and outstanding VRDP Shares pursuant to the terms of each of such shares (each a "Preferred Share Redemption" and collectively, the "Preferred Share Redemptions"). Such redemptions were independent of, and unrelated to, the Mergers. Each Target Fund is treated as a corporation for U.S. federal income tax purposes, has elected to be taxed as a regulated investment company under section 851 of the Code for all its taxable years, including without limitation the taxable year in which its respective Merger occurs, and has qualified and will continue to qualify for the tax treatment afforded regulated investment companies under the Code for each of its taxable years, including without limitation the taxable year in which its respective Merger occurs.

The Acquiring Fund similarly has been registered and operated, since it commenced operations, as a closed-end management investment company under the 1940 Act. The Acquiring Fund Shares are listed and traded on the NYSE under the symbol NMZ. In addition, the Acquiring Fund currently has outstanding three series of Adjustable Rate MuniFund Term Preferred. All the outstanding shares of the Acquiring Fund are treated as equity for U.S. federal income tax purposes and all the Acquiring Fund Shares to be issued in the Mergers will be treated as equity for U.S. federal income tax purposes. The Acquiring Fund is treated as a corporation for U.S. federal income tax purposes, has elected to be taxed as a regulated investment company under section 851 of the Code for all its taxable years, including without limitation the taxable year in which the Mergers occur, and has qualified and will continue to qualify for the tax treatment afforded regulated investment companies under the Code for each of its taxable years, including without limitation the taxable year in which the Mergers occur.

Merger Sub is a newly formed Massachusetts limited liability company and a direct, wholly-owned subsidiary of the Acquiring Fund that is and has been since the date of its organization disregarded as an entity separate from its owner within the meaning of section 301.7701-3 of the Treasury Regulations. Merger Sub has not elected, and will not elect, to be classified, with effect as of or prior to the Liquidation, as an association taxable as a corporation pursuant to section 301.7701-3 of the Treasury Regulations.

Upon satisfaction of certain terms and conditions set forth in the Plan, at the Effective Time each Target Fund will merge pursuant to applicable state law with and into Merger Sub with Merger Sub surviving and the common shares of the Target Fund will convert into Acquiring Fund Shares and all and all the issued and outstanding VRDP Shares of New Jersey Municipal and Pennsylvania Municipal will be converted into Acquiring Fund VRDP Shares. Pursuant to such state law and without any further action or deed being required, as of the Effective Time, all the rights, privileges, powers, assets, property and liabilities of each Target Fund and Merger Sub will become the rights, privileges, powers, assets, property and liabilities of Merger Sub and the separate legal existence of each Target Fund shall cease for all purposes. The aggregate net asset value as of the Valuation Time (as defined in the Plan) of the Acquiring Fund Shares to be received by each Target Fund common shareholder (including for this purpose any fractional Acquiring Fund Share to which such shareholder would be entitled), in each instance, will be equal to the aggregate net asset value as of the Valuation Time of the Target Fund common shares surrendered by such shareholder in the Merger. No fractional Acquiring Fund Shares will be issued to Target Fund common shareholders in connection with any Merger. In lieu thereof, the Acquiring Fund's transfer agent, on behalf of the common shareholders entitled to receive fractional Acquiring Fund Shares, will aggregate all fractional Acquiring Fund Shares and sell the resulting whole shares on the NYSE for the account of all shareholders of fractional interests, and each such shareholder will be entitled to a pro rata share of the proceeds from such sale. In the applicable Merger, each holder of VRDP Shares will receive one Acquiring Fund VRDP Share for each VRDP Share surrendered by such shareholder in the Reorganization and the aggregate liquidation preference and value as of the Effective Time of the Acquiring Fund VRDP Shares received by each holder of VRDP Shares will equal the aggregate liquidation preference and value as of the Effective Time of the VRDP Shares surrendered by such shareholder in the Reorganization and the terms of the Acquiring Fund VRDP Shares received by such shareholder will be substantially the same as the terms of the shares of Target Fund's VRDP Shares surrendered by such shareholder in the Reorganization.

Nuveen New Jersey Quality Municipal Income Fund<br> Nuveen Pennsylvania Quality Municipal Income Fund<br> Nuveen Missouri Quality Municipal Income Fund

Nuveen Municipal High Income Opportunity Fund

April 27, 2026

As soon as practicable after the Effective Time, Merger Sub will dissolve under applicable state law and the Acquiring Fund will assume all Merger Sub's liabilities and obligations, known and unknown, contingent or otherwise, whether or not determinable, and Merger Sub will distribute to the Acquiring Fund, which will be the sole member of Merger Sub at such time, all the assets of Merger Sub in complete liquidation of its interest in Merger Sub in accordance with a plan of dissolution adopted by Merger Sub.

Following each Merger, the Acquiring Fund (directly or indirectly through Merger Sub) will continue the Target Fund's historic business in that it will have an investment objective and investment strategies, policies, risks and restrictions similar to those of the Target Fund. In addition, the Acquiring Fund will use a significant portion of the Target Fund's historic business assets in its business. At the Effective Time, at least thirty-four percent (34%) of the total fair market value of each Target Fund's portfolio assets will meet the investment objective, strategies, policies, risks and restrictions of the Acquiring Fund. No Target Fund altered, or will alter, its portfolio in connection with the Reorganization to meet this thirty-four percent (34%) threshold. None of the Funds modified any of its investment objective, strategies, policies, risks or restrictions in connection with the Reorganization and the Acquiring Fund has no plan or intention to change any of its investment objective, strategies, policies, risks or restrictions after the Mergers.

In approving a Merger, the Board of Trustees of the Funds (collectively, the "Boards") participating in such Merger determined that the Plan and the transactions contemplated thereunder are in the best interests of its Fund and that the interests of the shareholders of its Fund will not be diluted as a result of the Merger. In making such determination, the Boards considered a number of factors as set forth under the heading "Proposal No. 1 – Merger of Each Target Fund into the Acquiring Fund – Information about the Mergers – Reasons for the Mergers" in the Joint Proxy Statement/Prospectus dated December 17, 2025 relating to the Registration Statement (as defined below).

**<u>Conclusion</u>**

Based on the foregoing, it is our opinion with respect to each Merger (subject to the conditions and limitations set forth above) that the merger under applicable state law of the Target Fund with and into Merger Sub with Merger Sub surviving, in accordance with the terms of the Plan, will qualify as a reorganization under section 368(a)(1) of the Code.

Nuveen New Jersey Quality Municipal Income Fund<br> Nuveen Pennsylvania Quality Municipal Income Fund<br> Nuveen Missouri Quality Municipal Income Fund

Nuveen Municipal High Income Opportunity Fund

April 27, 2026

The opinions set forth above (subject to the conditions and limitations set forth above) with respect to (i) the nonrecognition of gain or loss by the Target Funds, the Acquiring Fund and Merger Sub, (ii) the basis and holding period of the assets received by Merger Sub, (iii) the nonrecognition of gain or loss by each Target Fund's shareholders upon the receipt of the Acquiring Fund Shares and/or Acquiring Fund VRDP Shares, except with respect to cash received in lieu of a fractional Acquiring Fund Share, and (iv) the basis and holding period of the Acquiring Fund Shares and/or Acquiring Fund VRDP Shares received by each Target Fund's shareholders follow as a matter of law from the opinion that the transfers under the Plan will qualify as reorganizations under section 368(a)(1) of the Code.

The opinions expressed in this letter are based on the Code, the Income Tax Regulations promulgated by the Treasury Department thereunder and judicial authority reported as of the date hereof. We have also considered the positions of the Internal Revenue Service (the "Service") reflected in published and private rulings. Although we are not aware of any pending changes to these authorities that would alter our opinions, there can be no assurances that future legislative or administrative changes, court decisions or Service interpretations will not significantly modify the statements or opinions expressed herein. We do not undertake to make any continuing analysis of the facts or relevant law following the date of this letter or to notify you of any changes to such facts or law.

Our opinion is limited to those U.S. federal income tax issues specifically considered herein. We do not express any opinion as to any other U.S. federal tax issues, or any state, local or foreign tax law issues, arising from or related to the transactions contemplated by the Plan.

Although the discussion herein is based upon our best interpretation of existing sources of law and expresses what we believe a court would properly conclude if presented with these issues, no assurance can be given that such interpretations would be followed if they were to become the subject of judicial or administrative proceedings.

This opinion is furnished to the Funds for their benefit in connection with the Reorganization and is not to be relied upon, for any other purpose, in whole or in part, without our express prior written consent. Shareholders of the Funds may rely on this opinion, it being understood that we are not establishing any attorney-client relationship with any shareholder of any of the Funds. This letter is not to be relied upon for the benefit of any other person.

We hereby consent to the filing of this opinion as an exhibit to the Registration Statement on Form N-14 (File No. 333-290590) relating to the Reorganization filed by the Acquiring Fund with the Securities and Exchange Commission (the "Registration Statement"), to the discussion of this opinion in the Joint Proxy Statement/Prospectus dated December 17, 2025 relating to the Registration Statement and to the use of our name and to any reference to our firm in the Registration Statement. In giving such consent, we do not thereby admit that we are within the category of persons whose consent is required under section 7 of the Securities Act of 1933, as amended, or the rules and regulations of the Securities and Exchange Commission thereunder.

Nuveen New Jersey Quality Municipal Income Fund<br> Nuveen Pennsylvania Quality Municipal Income Fund<br> Nuveen Missouri Quality Municipal Income Fund

Nuveen Municipal High Income Opportunity Fund

April 27, 2026

Very truly yours,

/s/ VEDDER PRICE P.C.

VEDDER PRICE P.C.

## Exhibit 99.12

[Nuveen Municipal High Income Opportunity Fund POS EX](nmz-posex_061126.htm)

**Exhibit 99.(12)(b)**

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| ![](ex9912b001.jpg) | 2005 Market Street<br> Suite 2600 <br> Philadelphia, PA 19103<br> T: 215.564.8000 |

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April 27, 2026

Nuveen Municipal High Income Opportunity Fund

333 West Wacker Drive

Suite 3300

Chicago, IL 60606

Re: <u>Nuveen Municipal High Income Opportunity Fund (NMZ Series 1)</u>

Ladies and Gentlemen:

We have acted as special tax counsel ("<u>Counsel</u>") for Nuveen Municipal High Income Opportunity Fund, a Massachusetts business trust (the "<u>Fund</u>"), with respect to the Fund's issuance of Series 1 Variable Rate Demand Preferred Shares (the "<u>Series 1 VRDP Shares</u>") in connection with the merger of each of Nuveen New Jersey Quality Municipal Income Fund and Nuveen Pennsylvania Quality Municipal Income Fund with and into NMZ Merger Sub, LLC (the "<u>Mergers</u>") pursuant to the Agreement and Plan of Merger, dated as of March 19, 2026 (the "<u>Plan</u>").

Capitalized terms unless otherwise defined herein shall have the meanings ascribed to such in the Agreement.

In this connection, we have examined originals, or copies certified or otherwise identified to our satisfaction, of: (1) the Initial Series 1 Variable Rate Demand Preferred Shares (VRDP) Adjustable Rate Special Rate Period Purchase Agreement, dated as of April 27, 2026 (the "<u>Agreement</u>"), between the Fund and Wells Fargo Municipal Capital Strategies, LLC, as the purchaser thereunder, with respect to the Series 1 VRDP Shares; (2) the Plan; (3) the Proxy Statement for Holders of Variable Rate Demand Preferred Shares dated December 19, 2025 pertaining to the Mergers (the "<u>Proxy Statement</u>"), which includes the Confidential Information Memorandum of even date (the "<u>Memorandum</u>"); (4) resolutions adopted by the Board of Trustees pertaining to the Plan and resulting Mergers; (5) the Tender and Paying Agent Agreement between the Fund and The Bank of New York Mellon, dated as of April 27, 2026 (the "<u>Tender and Paying Agent Agreement</u>," and together with the Agreement, the "<u>Fund Agreements</u>"); (6) a copy of the Statement Establishing and Fixing the Rights and Preferences of Series 1 Variable Rate Demand Preferred Shares and the Notice of Special Rate Period (Adjustable Rate Special Rate Period) Designating the Initial Rate Period as a Special Rate Period, each was sent for filing with the Secretary of the Commonwealth of Massachusetts on April 23, 2026 (together, the "<u>Statement</u>"); and (7) such other records, certificates, documents and other papers as we deemed it necessary to examine for the purpose of this opinion. In such examination, we have assumed the genuineness of all signatures, the conformity to the originals of all of the documents reviewed by us as copies, the authenticity and completeness of all original documents reviewed by us in original or copy form and the legal competence of each individual executing any document. The items described in (1) through (7) above are referred to herein collectively as the "<u>Documents</u>."

**Stradley Ronon Stevens & Young, LLP** \| **stradley.com**<br> Chicago \| Los Angeles \| New York \| Philadelphia \| Washington, D.C.

Nuveen Municipal High Income Opportunity Fund (NMZ Series 1)

April 27, 2026

The opinions herein are subject to and conditioned upon the representations made by the Fund concerning factual matters (but not conclusions of law) and the assumptions set forth herein. The initial and continuing truth and accuracy of the Documents and such representations and assumptions at all relevant times constitutes an integral basis for the opinions expressed herein and these opinions are conditioned thereon.

Without limiting the foregoing, in rendering the opinions herein, we have relied, with the consent of the Fund, upon the written representations and covenants, among other things, concerning the issuance of the Series 1 VRDP Shares of the Fund in connection with the Mergers, set forth in the Officer's Certificate to Counsel of even date herewith from authorized officers of the Fund, which Officer's Certificate to Counsel has been delivered to Counsel and which representations, covenants and statements contained therein we have neither investigated nor verified. We have assumed and rely on the fact that such representations, covenants and statements of the Fund are true, correct and complete as of the date hereof and we rely on them in rendering the opinions herein.

We have reviewed the descriptions set forth in the Proxy Statement and the Memorandum of the Fund's investments, activities, operations, and governance, and the provisions of the Fund Agreements, the Plan and the Statement. We have relied upon the facts set forth in the Proxy Statement and Memorandum, and we may rely upon other factual representations of officers of the Fund. In addition, we have relied on certain additional facts and assumptions described below. In connection with rendering this opinion, we have assumed to be true and are relying upon (without any independent investigation or review thereof):

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A. The authenticity of all documents submitted to us as originals, the conformity to original documents of all documents submitted to us as copies, the authenticity of the originals of such documents, the conformity of final documents to all documents submitted to us as drafts, and the authenticity of such final documents;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;B. The genuineness of all signatures and the authority and capacity of the individual or individuals who executed any such document on behalf of any person;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;C. The accuracy of all factual representations, warranties and other statements made by all parties or as set forth in such documents;

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;D. The performance and satisfaction of all obligations imposed by any such documents on the parties thereto in accordance with their terms; and

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E. The completeness and accuracy of all records made available to us.

We have further assumed the accuracy of the statements and descriptions of the Mergers and the Fund's intended activities as described in the Proxy Statement and Memorandum. We have also assumed, without investigation, that all documents, certificates, representations, warranties and covenants upon which we have relied in rendering the opinions set forth below and that were given on or dated earlier than the date of this opinion continue to remain accurate, insofar as relevant to the opinions set forth herein, from such earlier date through and including the date of this opinion.

Nuveen Municipal High Income Opportunity Fund (NMZ Series 1)

April 27, 2026

Based solely on the foregoing, and subject to the qualifications, exceptions, assumptions and limitations expressed herein, we are of the opinion that, for U.S. federal income tax purposes and as of the effective time of the Mergers, the Series 1 VRDP Shares issued by the Fund in connection with the Mergers will qualify as equity in the Fund.

This opinion is furnished to the Fund solely for its benefit in connection with the Plan and resulting Mergers and is not to be relied upon for any other purpose, in whole or in part, without our express prior written consent. This opinion may be disclosed to (i) any governmental regulatory authority or regulator having jurisdiction over the Fund, if such disclosure is required by law or pursuant to the request of such governmental regulatory authority or regulator and provided that any such authority or regulator is not authorized to rely hereon, and (ii) any holders of Series 1 VRDP Shares (and beneficial owners of Series 1 VRDP Shares) and they may rely on it as if they were addressees of this opinion, it being understood that we are not establishing any lawyer-client relationship with the holders of Series 1 VRDP Shares (and beneficial owners of Series 1 VRDP Shares). This opinion is not to be relied upon for the benefit of any other person without our express prior written consent. Except in the Proxy Statement and the Registration Statement on Form N-14 (File No. 333-290590) relating to the Mergers filed by the Fund with Securities and Exchange Commission, this opinion is not to be referred to or quoted in any document, report or financial statement, or filed with, or delivered to, any other person or entity, in each instance without our prior written consent, except such disclosure as may be required by law or pursuant to the request of any governmental authority or regulator having regulatory authority over the Fund.

In addition to the assumptions set forth above, this opinion is subject to the following exceptions, limitations and qualifications:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;A. Our opinions are based upon our interpretation of the current provisions of the Internal Revenue Code of 1986 (the "Code") and current judicial decisions, administrative regulations and published notices, rulings and procedures. We note that there is no authority directly on point dealing with securities like the Series 1 VRDP Shares. Our opinions only represent our best judgment and are not binding on the Internal Revenue Service (the "<u>IRS</u>") or the courts and there is no assurance that the IRS will not successfully challenge the conclusions set forth herein. The IRS and the Treasury Department have not yet issued regulations or administrative interpretations with respect to various provisions of the Code relating to regulated investment company ("<u>RIC</u>") qualification. Consequently, no assurance can be given that future legislative, judicial or administrative changes, on either a prospective or retroactive basis, would not adversely affect the accuracy of the conclusions stated herein. We undertake no duty or obligation to advise you of any factual changes or changes in law which may occur after the date hereof.

Nuveen Municipal High Income Opportunity Fund (NMZ Series 1)

April 27, 2026

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;B. Our opinions are limited to the U.S. federal income tax matters specifically addressed herein, and no other opinions are rendered with respect to any other matter not specifically set forth in the foregoing opinions (including whether the Fund qualifies or will continue to qualify as a RIC).

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;C. Our opinions are limited in all respects to the federal tax law of the United States and we express no opinion on various state, local, or foreign tax consequences.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;D. The Fund's qualification and taxation as a RIC depend upon the Fund's ability to satisfy through actual operations the applicable asset composition, source of income, distribution and other requirements of the Code necessary to qualify and be taxed as a RIC, which operations we will not and have not reviewed.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;E. The foregoing opinions are based upon the proposed method of operation of the Fund as described in the Proxy Statement and Memorandum, and the representations and covenants set forth in the documents described and the assumptions set forth herein. We undertake no obligation to review at any time in the future either the Fund's operations or its compliance with such representations, covenants and assumptions. No assurance can be given that the Fund will satisfy the requirements of the Code necessary to qualify or be taxed as a RIC for any particular taxable year. Further, we assume no obligation to advise you of any changes in our opinions subsequent to the delivery of this opinion.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;F. In the event any one of the statements, representations, warranties, covenants or assumptions we have relied upon to issue these opinions is incorrect in a material respect, our opinions might be adversely affected and if so may not be relied on.

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| Very truly yours, |
| /s/ Stradley Ronon Stevens & Young, LLP |
| STRADLEY RONON STEVENS & YOUNG, LLP |

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| ![](ex9912b001.jpg) | 2005 Market Street<br> Suite 2600 <br> Philadelphia, PA 19103<br> T: 215.564.8000 |

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June 9, 2026

Nuveen Municipal High Income Opportunity Fund

333 West Wacker Drive

Suite 3300

Chicago, IL 60606

Re: <u>Nuveen Municipal High Income Opportunity Fund (NMZ Series 1)</u>

Ladies and Gentlemen:

We have acted as special tax counsel for Nuveen Municipal High Income Opportunity Fund, a Massachusetts business trust (the "<u>Fund</u>"), with respect to the Fund's issuance of Series 1 Variable Rate Demand Preferred Shares (the "<u>Series 1 VRDP Shares</u>") in connection with the merger of each of Nuveen New Jersey Quality Municipal Income Fund and Nuveen Pennsylvania Quality Municipal Income Fund with and into NMZ Merger Sub, LLC (the "<u>Mergers</u>") pursuant to the Agreement and Plan of Merger, dated as of March 19, 2026. In that capacity, we have provided you with our opinion to the effect that the Series 1 VRDP Shares issued by the Fund in connection with the Mergers will qualify as equity in the Fund for federal income tax purposes.

We hereby consent to the filing of such opinion as an exhibit to the Registration Statement on Form N-14 (File No. 333-290590) and to the discussion of such opinion, to the use of our name and to any reference to our firm in the Joint Proxy Statement/Prospectus included therein. In giving such consent, we do not thereby admit that we are within the category of persons whose consent is required under Section 7 of the Securities Act of 1933, as amended, or the rules and regulations of the Securities and Exchange Commission thereunder.

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| Very truly yours, |
| /s/ Stradley Ronon Stevens & Young, LLP |
| STRADLEY RONON STEVENS & YOUNG, LLP |

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