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DR. DOUGLAS LOGAN WILLIAMSON DNP
NPI 1386240844
Registered Nurse - Psychiatric/Mental Health in San Luis Obispo, CA

Active since December 09, 2020PECOS EnrolledAccepts Medicare Assignment
1304 ELLA ST STE B, SAN LUIS OBISPO, CA 93401(805) 541-6000(805) 541-6001 Get Directions Write a Review

NPPES record last updated: March 20, 2025. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Mar 20, 2025, Apr 10, 2021, Feb 4, 2021 and 1 more (4 updates tracked since 2020).

About Dr. Douglas Logan Williamson Dnp NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

DR. DOUGLAS LOGAN WILLIAMSON DNP (NPI 1386240844) is an individual psychiatric/mental health provider in San Luis Obispo, California, licensed in California (NP95016180) and active in the NPI registry since December 2020. He is enrolled in Medicare PECOS and is a graduate of Other (2020).

NPPES Registry Identity

NPI1386240844
Entity TypeIndividualMale
Primary Taxonomy163WP0808X
Provider Legal NameDR. DOUGLAS LOGAN WILLIAMSONCredential: DNP
Location Address1304 ELLA ST STE BSan Luis Obispo, CA 93401-4166
Mailing Address1304 Ella St Ste BSan Luis Obispo, CA 93401-4166 · (805) 541-6000 · Fax (805) 541-6001
Phone(805) 541-6000
Fax(805) 541-6001
Sole ProprietorNo
Medical School CMSOtherGraduated 2020
Enumeration DateDecember 9, 2020
Last NPPES UpdateMarch 20, 20254 updates tracked since enumeration
NPPES CertifiedMarch 20, 2025
✔ NPI 1386240844 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyRegistered Nurse · Psychiatric/Mental HealthNursing Service Providers
Taxonomy Code163WP0808X
License✔ Licensed in CA · NP95016180
1304 ELLA ST STE B, San Luis Obispo, CA 93401
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Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Dr. Douglas Logan Williamson Dnp is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID6103230479
PECOS Enrollment IDI20210127002643
Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignment

Medicare enrollment records show Douglas Williamson reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Pacific Psychiatry Inc., A Professional Medical Corporation
Same address
Psychiatry
1304 ELLA ST STE B
San Luis Obispo, CA 93401
  • Reassigned Medicare billing, California enrollment
  • 7 clinicians in this Medicare group
NPI 1902317472 (805) 541-6000

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Other Providers at the Same Location NPPES 7

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

JULIA ELIZABETH DAVISON PA-C
Physician Assistant
1304 ELLA ST STE B
SAN LUIS OBISPO, CA 93401
San Luis Obispo County (805) 541-6000
LARRY D HERRON MD INC
Orthopaedic Surgery
1304 ELLA ST STE B
SAN LUIS OBISPO, CA 93401
San Luis Obispo County (805) 541-4700
DOUGLAS P MURPHY MD
Psychiatry & Neurology (Child & Adolescent Psychiatry)
1304 ELLA ST STE B
SAN LUIS OBISPO, CA 93401
San Luis Obispo County (805) 541-6000
RICHARD ALTESMAN MD
Psychiatry & Neurology (Psychiatry)
1304 ELLA ST STE B
SAN LUIS OBISPO, CA 93401
San Luis Obispo County (805) 541-6000
KATIE JANE BAILEY PMHNP-BC
Nurse Practitioner (Psychiatric/Mental Health)
1304 ELLA ST STE B
SAN LUIS OBISPO, CA 93401
San Luis Obispo County (805) 541-6000
PACIFIC PSYCHIATRY INC., A PROFESSIONAL MEDICAL CORPORATION
Psychiatry & Neurology (Psychiatry)
1304 ELLA ST STE B
SAN LUIS OBISPO, CA 93401
San Luis Obispo County (805) 541-6000
ALLYSON GELMAN PA-C
Physician Assistant (Medical)
1304 ELLA ST STE B
SAN LUIS OBISPO, CA 93401
San Luis Obispo County (805) 541-6000

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Douglas Williamson's NPI number?

The NPI number for Douglas Williamson is 1386240844. It was assigned to this individual provider in the NPPES registry on December 9, 2020.

Where is Douglas Williamson located?

Douglas Williamson practices at 1304 Ella St Ste B, San Luis Obispo, CA 93401. The listed phone number is (805) 541-6000.

What is Douglas Williamson's specialty?

The primary specialty registered for this NPI is Registered Nurse, specializing in Psychiatric/Mental Health, with taxonomy code 163WP0808X.

Is Douglas Williamson enrolled in Medicare?

Yes. Douglas Williamson is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Which organization bills Medicare for Douglas Williamson's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Douglas Williamson reassigns Medicare benefits to Pacific Psychiatry Inc., A Professional Medical Corporation (San Luis Obispo, CA). The reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Douglas Williamson's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for Douglas Williamson was last updated on March 20, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 19 months ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.