Type 1 · Individual ✓ Active NPI ✓ Valid NPI checksum

Dr. William Douglas Pierce, PHD

Clinical Psychologist in Yankton, SD · enumerated 2006.

Data current as of Jul 13, 2026 · sourced from CMS NPPES

National Provider Identifier

1205801727

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Registry record

Entity type Individual (Type 1)

Name Dr. William Douglas Pierce

Credential PHD

Sex Male

Practice address 1000 W 4th St, Yankton, SD, 57078

Phone (605) 665-0258

Enumeration date Feb 19, 2006

Last updated in NPPES May 23, 2011

Taxonomy & licenses

103TC0700X Clinical Psychologist Behavioral Health & Social Service Providers · License 431 (SD) Primary

PHD · Doctor of Philosophy: A doctoral degree; in healthcare often held by clinical psychologists and researchers. About the PHD credential

Other identifiers

Identifier	Type	State	Issuer
6551840	Medicaid	SD	-

What is an NPI number?

A National Provider Identifier (NPI) is a unique 10-digit number that CMS assigns to every U.S. healthcare provider and organization under HIPAA. Type 1 NPIs identify individual providers; Type 2 NPIs identify organizations. The NPI appears on insurance claims, prescriptions, and credentialing paperwork, and never changes, even if the provider moves or changes specialty.

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Frequently asked questions

Is NPI 1205801727 active?

Yes, as of the latest NPPES snapshot, NPI 1205801727 is active (record last updated 2011-05-23).

How do I verify William Pierce's NPI record?

Cross-check NPI 1205801727 against the official CMS registry at npiregistry.cms.hhs.gov. This page mirrors the same public NPPES data with a monthly snapshot.

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Taryn Van Gilder-Pierce Clinical Psychologist · Yankton, SD NPI 1588639009 Yankton Bone Joint & Sports Medicine Center PC Orthopaedic Surgery Physician · Yankton, SD NPI 1609817584 Victoria Antle-Vlach Anesthesiology Physician · Yankton, SD NPI 1780615872 Sacred Heart Rural Health Clinics Foot & Ankle Surgery Podiatrist · Yankton, SD NPI 1962584037 Terence Pedersen Foot & Ankle Surgery Podiatrist · Yankton, SD NPI 1235213513 Kelly Rafferty Family Medicine Physician · Yankton, SD NPI 1609911098 Sacred Heart Health Services Physical Medicine & Rehabilitation Physician · Yankton, SD NPI 1316182579 Linda Richards Addiction (Substance Use Disorder) Counselor · Yankton, SD NPI 1134662620

Source: CMS NPPES (public data). Snapshot 2026-07-13. Provider record last updated 2011-05-23.