The sequence of countries in Part 57B follows, covering regular postage, semi-postal and air post issues (excluding souvenir sheets) for 2021.

Where noted, stamps issued in 2021 or previous years, are being held pending release of additional stamps that would complete an album page. These pages will appear in a future International Album supplement.

- Laos
- Latvia  
- Lebanon  
- Lesotho: On Hold  
- Liberia
- Liechtenstein  
- Lithuania  
- Luxembourg  
- Macao  
- Macedonia  
- Madagascar: On Hold  
- Malawi: On Hold  
- Malaysia  
- Maldive Islands
- Mali: On Hold  
- Malta  
- Marshall Islands
- Mauritania: On Hold  
- Mauritius
- Mayotte: On Hold  
- Mexico  
- Micronesia: On Hold

SCOTT INTERNATIONAL - 2021 57B SUPPLEMENT (PART 2) is categorised STAMPS / SUPPLEMENTS and sold by l'Imaginaire, a store and specialised website.