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MS. ALISA LYNN WILLIAMS MD M.D.
NPI 1720006398
Specialist in San Diego, CA

Active since July 18, 2006PECOS EnrolledAccepts Medicare Assignment
5555 RESERVOIR DR STE 307, SAN DIEGO, CA 92120(619) 299-3111(619) 299-3126 Get Directions Write a Review

NPPES record last updated: January 2, 2020. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Jan 2, 2020, Dec 3, 2018 (2 updates tracked since 2018).

About Ms. Alisa Lynn Williams Md M.d. NPPES

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

MS. ALISA LYNN WILLIAMS MD M.D. (NPI 1720006398) is an individual specialist in San Diego, California, licensed in California (GG60944) and active in the NPI registry since July 2006. She is enrolled in Medicare PECOS and is a graduate of University Of Tennessee, Hsc, College Of Medicine (1985).

NPPES Registry Identity

NPI1720006398
Entity TypeIndividualFemale
Primary Taxonomy174400000X
Provider Legal NameMS. ALISA LYNN WILLIAMS MDCredential: M.D.
Location Address5555 RESERVOIR DR STE 307San Diego, CA 92120-5134
Mailing Address5555 Reservoir Dr Ste 307San Diego, CA 92120-5134 · (619) 299-3111 · Fax (619) 299-3126
Phone(619) 299-3111
Fax(619) 299-3126
Sole ProprietorNo
Medical School CMSUniversity Of Tennessee, Hsc, College Of MedicineGraduated 1985
Enumeration DateJuly 18, 2006
Last NPPES UpdateJanuary 2, 20202 updates tracked since enumeration
✔ NPI 1720006398 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtySpecialistOther Service Providers
Taxonomy Code174400000X
License✔ Licensed in CA · GG60944
Definition
An individual educated and trained in an applied knowledge discipline used in the performance of work at a level requiring knowledge and skills beyond or apart from that provided by a general education or liberal arts degree.
5555 RESERVOIR DR STE 307, San Diego, CA 92120
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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

Ms. Alisa Lynn Williams Md M.d. 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 ID8628979465
PECOS Enrollment IDI20090122000461
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 Alisa Williams Md reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Alisa L Williams, MD, Facog, Inc.
Same address
Specialist
5555 RESERVOIR DR STE 307
San Diego, CA 92120
  • Reassigned Medicare billing, California enrollment
NPI 1083887921 (619) 299-3111

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

Areas of Expertise CMS Part B claims 3

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Cervical or vaginal cancer screening; pelvic and clinical breast examination G0101
This procedure involves checking for health issues in the lower abdomen and chest area. It helps identify early signs of certain conditions, increasing the chance for successful treatment. It's a routine check-up that's important for maintaining good health.
64 services64 patients
Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214
This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.
52 services43 patients
New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204
This is a first-time office or outpatient visit lasting between 45-59 minutes. The healthcare provider evaluates your health, discusses your medical history, and may suggest further tests or treatments. It's an opportunity to ask questions and understand your health better.
23 services23 patients

Other Providers at the Same Location NPPES 2

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

ALISA L WILLIAMS, MD, FACOG, INC.
Specialist
5555 RESERVOIR DR STE 307
SAN DIEGO, CA 92120
San Diego County (619) 299-3111
DANA DELELLIS MD
Internal Medicine
5555 RESERVOIR DR STE 307
SAN DIEGO, CA 92120
San Diego County (858) 220-4615

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 Alisa Williams Md's NPI number?

The NPI number for Alisa Williams Md is 1720006398. It was assigned to this individual provider in the NPPES registry on July 18, 2006.

Where is Alisa Williams Md located?

Alisa Williams Md practices at 5555 Reservoir Dr Ste 307, San Diego, CA 92120. The listed phone number is (619) 299-3111.

What is Alisa Williams Md's specialty?

The primary specialty registered for this NPI is Specialist with taxonomy code 174400000X.

Is Alisa Williams Md enrolled in Medicare?

Yes. Alisa Williams Md 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 Alisa Williams Md's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Alisa Williams Md reassigns Medicare benefits to Alisa L Williams, MD, Facog, Inc. (San Diego, 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 Alisa Williams Md'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 Alisa Williams Md was last updated on January 2, 2020. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 6 years 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.