First three digits · Pennsylvania
ZIP Codes Starting with
74 ZIP codes start with 166, sorted at the Altoona, PA (SCF 166) sectional center (USPS labeling list L005, effective October 1, 2026) in Pennsylvania: 67 residential ZIP codes across 7 counties and 7 PO Box or single-organization codes (Census 2020 ZCTAs and GeoNames postal codes, October 2026).
What do the digits 166 mean?
The first digit, 1, is one of ten national areas (Delaware, New York and Pennsylvania). The first three, 166, route mail to a sectional center: USPS labeling list L005 (effective October 1, 2026) sends letters for 166 to the Altoona, PA (SCF 166) facility. The last two digits pick the delivery area. By residents, the largest town names among the 166 ZIP codes are Altoona, Huntingdon, Hollidaysburg, Tyrone, Duncansville and Martinsburg.
The same facility sorts 2 prefixes, 133 ZIP codes in all: 166, 168.
Where are the 166 ZIP codes?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
All ZIP codes starting with 166
| County | ||||||
|---|---|---|---|---|---|---|
| 16601 | Altoona | Blair County | 33,515 | 395 | $58k | $147k |
| 16602 | Altoona | Blair County | 26,352 | 1,795 | $55k | $126k |
| 16603 | Altoona | Blair County | PO Box or unique | – | – | – |
| 16611 | Alexandria | Huntingdon County | 2,665 | 59 | $71k | $168k |
| 16613 | Ashville | Cambria County | 1,647 | 53 | $74k | $159k |
| 16616 | Beccaria | Clearfield County | 103 | 62 | $29k | $152k |
| 16617 | Bellwood | Blair County | 2,392 | 1,616 | $53k | $146k |
| 16619 | Blandburg | Cambria County | 393 | 812 | $85k | $110k |
| 16620 | Brisbin | Clearfield County | 326 | 459 | $58k | $148k |
| 16621 | Broad Top | Huntingdon County | 604 | 38 | $71k | $124k |
| 16622 | Calvin | Huntingdon County | 82 | 11 | $34k | $171k |
| 16623 | Cassville | Huntingdon County | 492 | 44 | $62k | $189k |
| 16624 | Chest Springs | Cambria County | 253 | 87 | $58k | $203k |
| 16625 | Claysburg | Blair County | 3,147 | 98 | $55k | $164k |
| 16627 | Coalport | Clearfield County | 1,927 | 60 | $64k | $93k |
| 16629 | Coupon | Cambria County | PO Box or unique | – | – | – |
| 16630 | Cresson | Cambria County | 4,726 | 824 | $58k | $153k |
| 16631 | Curryville | Blair County | 57 | 109 | – | $238k |
| 16633 | Defiance | Bedford County | 313 | 2,129 | $91k | $87k |
| 16634 | Dudley | Huntingdon County | 262 | 80 | $59k | $90k |
| 16635 | Duncansville | Blair County | 12,003 | 212 | $70k | $192k |
| 16636 | Dysart | Cambria County | 808 | 29 | $90k | $172k |
| 16637 | East Freedom | Blair County | 2,345 | 119 | $56k | $120k |
| 16638 | Entriken | Huntingdon County | 58 | 62 | $87k | $214k |
| 16639 | Fallentimber | Cambria County | 1,390 | 29 | $75k | $138k |
| 16640 | Flinton | Cambria County | 1,077 | 77 | $54k | $139k |
| 16641 | Gallitzin | Cambria County | 2,348 | 182 | $65k | $117k |
| 16644 | Glasgow | Cambria County | PO Box or unique | – | – | – |
| 16645 | Glen Hope | Clearfield County | 204 | 107 | $69k | – |
| 16646 | Hastings | Cambria County | 2,185 | 121 | $66k | $119k |
| 16647 | Hesston | Huntingdon County | 864 | 34 | $88k | $304k |
| 16648 | Hollidaysburg | Blair County | 14,904 | 248 | $82k | $220k |
| 16650 | Hopewell | Bedford County | 1,796 | 39 | $62k | $158k |
| 16651 | Houtzdale | Clearfield County | 5,484 | 139 | $66k | $111k |
| 16652 | Huntingdon | Huntingdon County | 15,866 | 91 | $68k | $208k |
| 16654 | Huntingdon | Huntingdon County | 1,906 | 29,781 | – | – |
| 16655 | Imler | Bedford County | 1,427 | 44 | $67k | $163k |
| 16656 | Irvona | Clearfield County | 1,148 | 42 | $48k | $101k |
| 16657 | James Creek | Huntingdon County | 1,170 | 24 | $63k | $215k |
| 16659 | Loysburg | Bedford County | 255 | 155 | $73k | $163k |
| 16660 | McConnellstown | Huntingdon County | PO Box or unique | – | – | – |
| 16661 | Madera | Clearfield County | 944 | 42 | $58k | $114k |
| 16662 | Martinsburg | Blair County | 6,069 | 113 | $74k | $221k |
| 16663 | Morann | Clearfield County | PO Box or unique | – | – | – |
| 16664 | New Enterprise | Bedford County | 2,195 | 55 | $76k | $166k |
| 16665 | Newry | Blair County | 253 | 542 | $66k | $267k |
| 16666 | Osceola Mills | Clearfield County | 2,999 | 128 | $63k | $119k |
| 16667 | Osterburg | Bedford County | 1,371 | 76 | $74k | $163k |
| 16668 | Patton | Cambria County | 3,507 | 66 | $59k | $115k |
| 16669 | Petersburg | Huntingdon County | 2,099 | 20 | $79k | $216k |
| 16670 | Queen | Bedford County | 89 | 138 | $46k | $191k |
| 16671 | Ramey | Clearfield County | 411 | 168 | $79k | $102k |
| 16672 | Riddlesburg | Bedford County | 177 | 42 | $92k | $97k |
| 16673 | Roaring Spring | Blair County | 5,204 | 151 | $71k | $160k |
| 16674 | Robertsdale | Huntingdon County | 548 | 35 | $64k | $108k |
| 16675 | Saint Boniface | Cambria County | 88 | 36 | $40k | $73k |
| 16677 | Sandy Ridge | Centre County | 239 | 79 | – | – |
| 16678 | Saxton | Bedford County | 2,452 | 51 | $55k | $153k |
| 16679 | Six Mile Run | Bedford County | 656 | 29 | $51k | $90k |
| 16680 | Smithmill | Clearfield County | 359 | 49 | $82k | $104k |
| 16681 | Smokerun | Clearfield County | PO Box or unique | – | – | – |
| 16682 | Sproul | Blair County | 402 | 5,221 | $75k | – |
| 16683 | Spruce Creek | Huntingdon County | 353 | 18 | $91k | $259k |
| 16684 | Tipton | Blair County | 108 | 2,455 | $34k | – |
| 16685 | Todd | Huntingdon County | 303 | 27 | $140k | $236k |
| 16686 | Tyrone | Blair County | 13,427 | 91 | $69k | $173k |
| 16689 | Waterfall | Fulton County | 389 | 22 | $60k | $198k |
| 16691 | Wells Tannery | Fulton County | 325 | 11 | $67k | $208k |
| 16692 | Westover | Clearfield County | 923 | 47 | $74k | $163k |
| 16693 | Williamsburg | Blair County | 3,795 | 49 | $63k | $154k |
| 16694 | Wood | Huntingdon County | 355 | 85 | $76k | $123k |
| 16695 | Woodbury | Bedford County | 941 | 68 | $72k | $170k |
| 16698 | Houtzdale | Clearfield County | PO Box or unique | – | – | – |
| 16699 | Cresson | Cambria County | no residents | 0 | – | – |
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; GeoNames postal codes (CC BY 4.0) for codes without a residential area.