Historical area-number reference

Social Security Number Prefixes for Wisconsin

The historical area-number ranges listed for Wisconsin are 387-399.

Historical cutoff: June 25, 2011 · Reference reviewed: 2026-09-12

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Area-number ranges1listed ranges
Lowest listed area387historical
Highest listed area399historical
Area numbers listed13across the ranges
Historical only: These ranges do not prove birthplace, current residence, address or identity. They do not apply to new SSNs assigned after June 25, 2011.

Plain-language answer

What Wisconsin prefixes mean

Before June 25, 2011, an older SSN beginning with an area number in the ranges below was associated with Wisconsin in the historical assignment record, usually through the mailing address on the original application.

For example, an old number beginning with 387 may fit this historical Wisconsin area-number record. This does not identify a person and does not show where the person lives now.

Listed ranges

Wisconsin area-number ranges

Historical Wisconsin area-number ranges before June 25, 2011
Area-number rangeCount of area numbers
387–39913

Know the limit

Why newer numbers are different

Randomization ended the geographic connection for new numbers. The first three digits of a newer SSN cannot reliably tell you a state or territory.

This page is an educational historical reference. It is not an identity lookup, background check or current-location search.

Quick answers

Wisconsin SSN prefix FAQs

What are the Social Security number prefixes for Wisconsin?

The historical area-number ranges listed for Wisconsin are 387-399. These ranges apply only to older numbers issued before June 25, 2011.

Does a Wisconsin prefix show where someone lives?

No. A historical prefix was generally tied to the mailing address on the original application, not a current address, birthplace or identity.

Do these prefixes apply to newer SSNs?

No. Since June 25, 2011, new numbers have been assigned randomly and the first three digits no longer have geographic meaning.

Can this page identify a person?

No. A prefix is only a historical reference. It cannot confirm who owns a number or identify a person.