| District ID | 3rd District |
| Representative | John P. Sarbanes |
| Party Affiliation | Democrat |
| Partisan Voting Index (PVI) | D+13 |
| 21797 |
| 21794 |
| 21784 |
| 21771 |
| 21738 |
| 21737 |
| 21723 |
| 21409 |
| 21405 |
| 21403 |
| 21402 |
| 21401 |
| 21240 |
| 21226 |
| 21225 |
| 21163 |
| 21146 |
| 21144 |
| 21122 |
| 21113 |
| 21108 |
| 21104 |
| 21090 |
| 21077 |
| 21076 |
| 21075 |
| 21061 |
| 21060 |
| 21056 |
| 21054 |
| 21046 |
| 21045 |
| 21044 |
| 21043 |
| 21042 |
| 21037 |
| 21036 |
| 21032 |
| 21029 |
| 21012 |
| 20833 |
| 20794 |
| 20777 |
| 20763 |
| 20759 |
| 20723 |
| 20701 |