Company: NMZ
Filing Date: 2025-11-18
Form Type: N-14 8C/A
Source: 0001999371-25-018025
Chunk: 304

Company: NUVEEN MUNICIPAL HIGH INCOME OPPORTUNITY FUND
Filing Date: 2025-11-18
Form: N-14 8C/A
Chunk 304
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 to repay short-term obligations. |

| NP | Issuers                                                                                 
 (or supporting institutions) rated Not Prime do not fall within any of the Prime rating 
 categories.                                                                             |

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U.S. MUNICIPAL SHORT-TERM OBLIGATION RATINGS

We use the Municipal Investment Grade (MIG) scale for US municipal cash flow notes, bond anticipation notes and certain other short-term obligations, which typically mature in three years or less.

| MIG 1 | This designation denotes superior credit quality. Excellent                                                                    
 protection is afforded by established cash flows, highly reliable liquidity support, or demonstrated broad-based access to the 
 market for refinancing.                                                                                                        |

| MIG 2 | This designation denotes strong credit quality. Margins                   
 of protection are ample, although not as large as in the preceding group. |

| MIG 3 | This designation denotes acceptable credit quality.                                                                        
 Liquidity and cash-flow protection may be narrow, and market access for refinancing is likely to be less well-established. |

| SG | This                                                                                    
 designation denotes speculative-grade credit quality. Debt instruments in this category 
 may lack sufficient margins of protection.                                              |

Fitch Ratings, Inc.—A brief description of the applicable Fitch Ratings, Inc. (“Fitch”) ratings symbols and meanings (as published by Fitch) follows:

Rated entities in a number of sectors, including financial and non-financial corporations, sovereigns, insurance companies and certain sectors within public finance, are generally assigned Issuer Default Ratings (IDRs). IDRs are also assigned to certain entities or enterprises in global infrastructure, project finance and public finance. IDRs opine on an entity’s relative vulnerability to default – including by way of a distressed debt exchange (DDE) – on financial obligations

The “threshold” default risk addressed by the IDR is generally that of the financial obligations whose non-payment would best reflect the uncured failure of that entity. As such, IDRs also address relative vulnerability to bankruptcy, administrative receivership or similar concepts.

In aggregate, IDRs provide an ordinal ranking of issuers based on the agency’s view of their relative vulnerability to default, rather than a prediction of a specific percentage likelihood of default.

LONG-TERM CREDIT RATINGS

| AAA | Highest                                                                                   
 credit quality. ‘AAA’ ratings denote the lowest expectation of default risk.              
 They are assigned only in cases of exceptionally strong capacity for payment of financial 
 commitments. This capacity is highly unlikely to be adversely