NPI registry status
Active
2026 NPPES data Family Nurse Practitioner NPI 1427169762 FNP
Verify on CMS → Sara Okabayashi-Williams, FNP
Family Nurse Practitioner in Daly City, California.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 210,832 in Family Nurse Practitioner, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
2K
Medicare Part D claims · 180 beneficiaries · Family Nurse Practitioner avg: 1K
Generic prescribing
84%
generic claims · 14% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2023
What the federal data shows
Sara Okabayashi-Williams, FNP filed 2,123 Medicare Part D claims in 2023 as a Family Nurse Practitioner in Daly City, California, prescribing 84% generic.
- 2K
- Part D claims, 2023
- 84%
- generic prescribing
- ≥85th
- pct by Part D claim volume (lower-bound band)
Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) - no proprietary rating or editorial opinion is applied.
Federal trust snapshot
What official records show about Sara Okabayashi-Williams, FNP
Federal records show an active NPI with Medicare Part D prescribing activity — verifiable registry data, not a proprietary rating.
- Verified
NPI registry status
Active listing in the CMS National Provider Identifier Registry (NPI 1427169762), first enumerated 08/31/2006.
Source: CMS NPPES
- Reported
Medicare Part D participation
Filed 2,123 Medicare Part D prescription claims in the 2023 CMS public use file — indicates active Medicare prescribing participation.
Source: CMS Part D Prescriber PUF
- Reported
Hospital affiliations
1 CMS Care Compare hospital affiliation on record — practice footprint from the Doctors and Clinicians file.
Source: CMS Care Compare
- State context
State board disciplinary context
California statewide board action statistics are published annually — these figures describe aggregate state activity, not Sara Okabayashi-Williams, FNP's individual license status. Verify directly with the state medical board.
Source: MBC annual report 2023
- Not in federal data
Individual sanction lookup
PlainDoctor does not publish per-provider disciplinary determinations. Confirm current license and any individual actions through the state medical board or FSMB verification service.
Source: State medical board / FSMB
This trust snapshot summarizes only what appears in federal CMS/NPPES public records. It is not a composite score, star rating, patient review, or clinical recommendation. PlainDoctor never fabricates reviews or AggregateRating schema.
CMS NPPES provider registry desk
NPI 1427169762 · Family Nurse Practitioner
NPI-10 · ENUM-LEGACY · TAX-MEGA · RX-MID · BOOK-MID · PHOTO-ENUM
- NPI-10 1427169762
- ENUM-LEGACY 2006
- TAX-MEGA 211K Family Nurse
- RX-MID 2,123
- BOOK-MID 15,115 in California
- PHOTO-ENUM Kristi Lafferty · 2006
Sara Okabayashi-Williams, FNP's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
2,123 ≥ 85th percentile 85% of 1,370,886 prescribers are in lower value bands
Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
The percentile is a conservative 100-claim band: it counts only prescribers in lower claim-volume bands. Medicare Part D claim volume is activity context, not a quality measure or recommendation. See methodology § corpus placement.
Source CMS Medicare Part D Prescriber Public Use File · 2023
What does the federal data show about Sara Okabayashi-Williams, FNP?
Quality data not reportedPrimary specialty
Family Nurse Practitioner
Medicare Part D claims
2,123 74% vs specialty avg
Specialty distribution in California
How Family Nurse Practitioner compares to other specialties among California providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Family Nurse Practitioner. Verify directly:
How MIPS and board certification work
The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.
Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).
Practice Address
Provider Details
| NPI | 1427169762 |
|---|---|
| Specialty | Family Nurse Practitioner |
| Credentials | FNP |
| Gender | Female |
| NPI Issued | 08/31/2006 |
Hospital and facility affiliations
Facilities where Sara Okabayashi-Williams, FNP bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" - a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.
County OF San Mateo
Daly City, CA
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
License & disciplinary context - California MBC 2023 annual report
Aggregate state board data only, NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~150K California medical licensees in 2023 - they are NOT specific to Sara Okabayashi-Williams, FNP. To verify Sara Okabayashi-Williams, FNP's current license status, search the MBC public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
576
Total board actions, California 2023
Across 556 cases
3.84
Actions per 1,000 licensees
California statewide rate
probation
Most common action type
186 cases
MBC publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the California disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.
Brand vs generic prescribing mix · Typical
Sara Okabayashi-Williams, FNP - brand share 14.0%
Family Nurse Practitioner average
14% brand-name claims vs 84% generic, on 2,123 2023 Medicare Part D claims.
The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
2,123
Total Claims
$289K
Total Drug Cost
180
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 4,710
- Total Day Supply
- 137,830
- Brand vs Generic
- 14% brand / 84% generic
- Brand Drug Cost
- $229K
- Generic Drug Cost
- $58K
- Antibiotic Claims
- 19
Patient Demographics
- Average Patient Age
- 68.9 years
- Avg HCC Risk Score
- 1.33
- Gender Split
- 62% female / 38% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Sara Okabayashi-Williams, FNP prescribes most
Top Medicare Part D drugs by claim count, 2023
- Atorvastatin Calcium
Atorvastatin Calcium
155 claims
- Amlodipine Besylate
Amlodipine Besylate
111 claims
- Metformin Hcl
Metformin Hcl
109 claims
- Losartan Potassium
Losartan Potassium
101 claims
- Lisinopril
Lisinopril
76 claims
- Metoprolol Succinate
Metoprolol Succinate
71 claims
- Levothyroxine Sodium
Levothyroxine Sodium
68 claims
- Omeprazole
Omeprazole
62 claims
| Drug | Claims |
|---|---|
| Atorvastatin Calcium | 155 |
| Amlodipine Besylate | 111 |
| Metformin Hcl | 109 |
| Losartan Potassium | 101 |
| Lisinopril | 76 |
| Metoprolol Succinate | 71 |
| Levothyroxine Sodium | 68 |
| Omeprazole | 62 |
| Pravastatin Sodium | 58 |
| Glipizide | 52 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Family Nurse Practitioner Overview
How Sara Okabayashi-Williams, FNP fits within the Family Nurse Practitioner landscape nationally.
210,832
Family Nurse Practitioner Providers in US
56
States with Family Nurse Practitioner
1,222
Avg Claims per Provider
Sara Okabayashi-Williams, FNP's 2,123 claims are above the specialty average of 1,222.
Nationwide Family Nurse Practitioner peers with similar MIPS or enrollment year
Two federal-record peer sets for Okabayashi-Williams, both outside California so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2006)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Family Nurse Practitioner Providers in California
Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as Okabayashi-Williams.
One of 15,115 Family Nurse Practitioner providers enrolled in California, 5 are shown here.
Dr. Danielle Aaroe
FAMILY NURSE PRACTIT
Oroville, CA
Joshua Aaron
Mission Hills, CA
Dr. Orly Aaron
NP
San Francisco, CA
Paris Gilbert Russ Aaron
Sacramento, CA
Dr. Alvin Joseph Abad
FNP-C
San Francisco, CA
Compare Family Nurse Practitioner nationally: see state-by-state distribution →
Frequently Asked Questions
What is Sara Okabayashi-Williams, FNP's specialty? ▼
Sara Okabayashi-Williams, FNP specializes in Family Nurse Practitioner and practices in Daly City, California. Credentials: FNP.
How much does Sara Okabayashi-Williams, FNP prescribe under Medicare Part D? ▼
In 2023, Sara Okabayashi-Williams, FNP wrote 2,123 Medicare Part D claims totaling $289K in drug costs for 180 beneficiaries.
Where is Sara Okabayashi-Williams, FNP located? ▼
Sara Okabayashi-Williams, FNP is located at 380 90TH ST, Daly City, CA, 94015. Phone: (650) 301-8406.
What is Sara Okabayashi-Williams, FNP's NPI number? ▼
Sara Okabayashi-Williams, FNP's National Provider Identifier (NPI) is 1427169762, issued on 08/31/2006.
Does Sara Okabayashi-Williams, FNP prescribe more brand-name or generic drugs? ▼
Sara Okabayashi-Williams, FNP's prescribing is 14% brand-name and 84% generic drugs by claim count, with $229K in brand drug costs.
How many Family Nurse Practitioner providers are there in the US? ▼
There are 210,832 Family Nurse Practitioner providers across 56 states in the US. The average Family Nurse Practitioner provider writes 1,222 Medicare Part D claims per year.
What drugs does Sara Okabayashi-Williams, FNP prescribe most often? ▼
Based on 2023 Medicare Part D data, Sara Okabayashi-Williams, FNP's most frequently prescribed drugs include Atorvastatin Calcium, Amlodipine Besylate, Metformin Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Sara Okabayashi-Williams, FNP accept Medicare? ▼
Sara Okabayashi-Williams, FNP appears in CMS Medicare data with 2,123 Part D claims and 180 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Sara Okabayashi-Williams, FNP's credentials? ▼
Sara Okabayashi-Williams, FNP's NPI is 1427169762 with credentials FNP. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.
Data Sources
View source datasets and methodology notes
- Provider Directory
- CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
- Specialty Classification
- NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
- Prescribing Data
- CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
- Limitations
- Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.
See our complete data methodology for details on how we collect and process government data.
Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).
Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 2026.