First three digits · Minnesota
ZIP Codes Starting with
13 ZIP codes start with 556, sorted at the Duluth, MN (SCF 556) sectional center (USPS labeling list L005, effective October 1, 2026) in Minnesota: 13 residential ZIP codes across 3 counties (Census 2020 ZCTAs and GeoNames postal codes, October 2026).
What do the digits 556 mean?
The first digit, 5, is one of ten national areas (Iowa, Minnesota, Montana, North Dakota, South Dakota and Wisconsin). The first three, 556, route mail to a sectional center: USPS labeling list L005 (effective October 1, 2026) sends letters for 556 to the Duluth, MN (SCF 556) facility. The last two digits pick the delivery area. By residents, the largest town names among the 556 ZIP codes are Two Harbors, Grand Marais, Silver Bay, Grand Portage, Lutsen and Finland.
The same facility sorts 3 prefixes, 102 ZIP codes in all: 556, 557, 558.
Where are the 556 ZIP codes?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
All ZIP codes starting with 556
| County | ||||||
|---|---|---|---|---|---|---|
| 55601 | Beaver Bay | Lake County | 128 | 8 | $56k | $242k |
| 55602 | Brimson | St. Louis County | 346 | 1 | $74k | $248k |
| 55603 | Finland | Lake County | 490 | 2 | $62k | $217k |
| 55604 | Grand Marais | Cook County | 3,719 | 5 | $73k | $353k |
| 55605 | Grand Portage | Cook County | 572 | 8 | $56k | $140k |
| 55606 | Hovland | Cook County | 198 | 1 | $85k | $318k |
| 55607 | Isabella | Lake County | 192 | 1 | $88k | $213k |
| 55609 | Knife River | Lake County | 131 | 53 | $78k | – |
| 55612 | Lutsen | Cook County | 535 | 3 | $81k | $415k |
| 55613 | Schroeder | Cook County | 232 | 4 | $59k | $406k |
| 55614 | Silver Bay | Lake County | 2,485 | 11 | $73k | $182k |
| 55615 | Tofte | Cook County | 379 | 2 | $61k | $276k |
| 55616 | Two Harbors | Lake County | 7,250 | 15 | $76k | $259k |
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; GeoNames postal codes (CC BY 4.0) for codes without a residential area.