Kosarzyn was formerly part of the German Empire. In the German Empire, the place was called Kuschern.
The place is now called Kosarzyn and belongs to Poland.
| Historical place name | Country | Administration | Time |
|---|---|---|---|
| Kuschern | German Empire | Guben | 1939 |
| Kosarzyn | Under Polish administration | Gubin | 1945 |
| Kosarzyn | Poland | Zielona Góra | 1992 |