| First Round | ||||
| *advanced from qualifying rounds. All other clubs exempt from qualifying | ||||
| Eastern Bracket | ||||
| 1/14/28 | Boston Wonder Workers | 3 : 0 | Whittall Carpet Mills | |
| 1/14/28 | New Bedford Whalers | 2 : 1 | J & P Coats | |
| 1/15/28 | New York Nationals | 6 : 1 | I.R.T. Celtics (NYC)* | |
| 1/15/28 | Bethlehem Steel | 3 : 1 | Centennial FC (Phi.)* | |
| 1/15/28 | Brooklyn Wanderers | 4 : 0 | Trenton FC | |
| 1/15/28 | Fall River Marksmen | 5 : 1 | MacKenzie FC (Niagara Falls)* | |
| 1/15/28 | New York Giants | 3 : 2 | Newark Skeeters | |
| 1/15/28 | Providence Clamdiggers | 5 : 0 | Danersk FC (CT) | |
| Western Bracket | ||||
| 1/15/28 | Magyar American FC (Cle.)* | 2 : 1 | Wellston FC (St. L) | |
| 1/15/28 | Gar Wood FC (Det.)* | 2 : 5 | Bricklayers FC (Chi.) | |
| 1/15/28 | Morgan Haulers (St. L) | 3 : 6 | Buda A.A. (Harvey, Ill.)* | |
| 1/15/28 | Canadian Club (Chi.) | 4 : 1 | Tablers FC (St. L) | |
| 1/22/28 | Ben Miller SC (St. L) | 2 : 0 | Swedish American FC (Det.) | |
| 1/22/28 | Walkerville (Ont.)* | 0 : 5 | Holley Carburetor (Det.) | |
| 1/23/28 | Vienna FC (Chi.) | 1 : 0 | Thistle FC (Chi.) | |
| 1/22/28 |
Sparta A & BA (Chi.) | 2 : 0 | Olympia FC (Chi.) | |
| Second Round | ||||
| Eastern Bracket | ||||
| 1/28/28 | J & P Coats | 1 : 0 | Providence Clamdiggers | |
| 1/29/28 | Fall River Marksmen | 2 : 1 | Boston Wonder Workers | |
| 1/29/28 | Brooklyn Wanderers | 1 : 1 (aet) | Bethlehem Steel | |
| 2/4/28 | R | Brooklyn Wanderers | 3 : 2 (aet) | Bethlehem Steel |
| 2/5/28 | New York Nationals | 2 : 2 (aet) | New York Giants | |
| 2/12/28 | R | New York Giants | 1 : 2 | New York Nationals |
| Western Bracket | ||||
| 2/5/28 | Ben Miller SC | 2 : 1 | Canadian Club | |
| 2/5/28 | Bricklayers FC | 4 : 0 | Buda A.A. | |
| 2/5/28 | Magyar American FC | 5 : 2 | Vienna FC | |
| 2/5/28 | Holley Carburetor | 3 : 4 (aet) | Sparta A & BA | |
| Quarterfinals | ||||
| 2/26/28 | Brooklyn Wanderers | 0 : 1 | New York Nationals | |
| 2/26/28 | J & P Coats | 2 : 1 | Fall River Marksmen | |
| 2/26/28 | Ben Miller FC | 4 : 3 (aet) | Magyar American FC | |
| 2/26/28 | Bricklayers FC | 1 : 0 | Sparta A & BA | |
| Semifinals | ||||
| 3/18/18 | New York Nationals | 5 : 3 | J & P Coats | |
| 3/18/28 | Ben Miller FC | 0 : 2 | Bricklayers FC | |
| Final | ||||
| at Polo Grounds, New York, New York | ||||
| 4/9/28 | New York Nationals | 1 : 1(aet) | Bricklayers FC | |
| at Soldier Field, Chicago, Illinois | ||||
| 4/15/28 | R | New York Nationals | 3 : 0 | Bricklayers FC |
| KEY – w/o – Walkover, R – Replay | ||||