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2026 NPPES data Specialist NPI 1972504652 M.D.
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Glen O'Sullivan, M.D.

Specialist in Mount Shasta, 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 69,608 in Specialist, 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 · 466 beneficiaries · Specialist avg: 1K
MIPS score
83.8/100
▲ 0 pts above national avg 83.5 · Above neutral
Industry payments
$17.85
1 payments · CMS Open Payments (Sunshine Act)
Verify NPI on CMS Methodology
Compiled from official public sources by the editorial process.

What the federal data shows

Glen O'Sullivan, M.D. reported a CMS MIPS final score of 83.8/100 - above the 83.5 national average - and filed 1,633 Medicare Part D claims in 2023.

83.8/100
MIPS score · +0 vs avg
2K
Part D claims, 2023
$17.85
industry payments (Sunshine Act)
≥39th
pct among measured MIPS (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.

CMS NPPES provider registry desk

NPI 1972504652 · Specialist

NPI-10 · ENUM-LEGACY · TAX-MEGA · MIPS-INLINE · RX-MID · BOOK-MID · PHOTO-FINISH

  • NPI-10 1972504652
  • ENUM-LEGACY 2005
  • TAX-MEGA 70K Specialist
  • MIPS-INLINE 83.8/100
  • RX-MID 1,633
  • BOOK-MID 6,672 in California
  • PHOTO-FINISH James Loos · ±0.0

MIPS final-score neighbourhood

Same-specialty nationwide peers by CMS final score, not geographic proximity

MIPS pts

What this shows Nearest measured MIPS peers for this NUCC specialty (2023 performance year).

Source CMS Quality Payment Program (MIPS) As of 2023

Glen O'Sullivan, M.D.'s MIPS score vs every measured U.S. clinician

CMS Merit-based Incentive Payment System (MIPS) final score, 2023, the federal quality measure. Clinicians whose score CMS assigned without scoring any category are excluded.

84 ≥ 39th percentile 39% of 454,083 measured providers are in lower value bands

0–10: 8,684 measured providers (2%). Below this entry. 10–20: 3,008 measured providers (1%). Below this entry. 20–30: 3,069 measured providers (1%). Below this entry. 30–40: 2,746 measured providers (1%). Below this entry. 40–50: 2,928 measured providers (1%). Below this entry. 50–60: 5,882 measured providers (1%). Below this entry. 60–70: 13,906 measured providers (3%). Below this entry. 70–80: 94,570 measured providers (21%). Below this entry. 80–90: 129,887 measured providers (29%). This entry sits in this band. 90+: 189,403 measured providers (42%). Above this entry. This provider 0 100 every measured MIPS clinician, bucketed by value

Each bar is a band; taller bars hold more measured providers. 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 whole-score-point band: it counts only measured clinicians in lower score bands. A CMS MIPS metric is not a recommendation or a clinical-quality rating by PlainDoctor. See methodology § corpus placement.

Source CMS Merit-based Incentive Payment System (MIPS) · 2023

Where Glen O'Sullivan, M.D. sits

This provider among specialist peers

Across the 4,261 specialist providers who report both Medicare Part D prescribing and a MIPS quality score, Glen O'Sullivan, M.D. writes more Part D claims than 68% of them and scores higher on MIPS quality than 50% - placing this provider in the high-volume, high-quality quadrant. Volume reflects patient-panel size and specialty, not quality; the two axes are independent.

Lower volume · High qualityHigh volume · High qualityLower volume · Lower qualityHigh volume · Lower quality0255075100024.148.372.496.6Part D claim volume, percentile in specialtyMIPS quality, percentilePoint, Part D claim volume, percentile in specialty: 77 · MIPS quality, percentile: 0Point, Part D claim volume, percentile in specialty: 58 · MIPS quality, percentile: 92Point, Part D claim volume, percentile in specialty: 32 · MIPS quality, percentile: 37Point, Part D claim volume, percentile in specialty: 88 · MIPS quality, percentile: 90Point, Part D claim volume, percentile in specialty: 52 · MIPS quality, percentile: 25Point, Part D claim volume, percentile in specialty: 60 · MIPS quality, percentile: 23Point, Part D claim volume, percentile in specialty: 28 · MIPS quality, percentile: 82Point, Part D claim volume, percentile in specialty: 35 · MIPS quality, percentile: 80Point, Part D claim volume, percentile in specialty: 20 · MIPS quality, percentile: 63Point, Part D claim volume, percentile in specialty: 18 · MIPS quality, percentile: 0Point, Part D claim volume, percentile in specialty: 30 · MIPS quality, percentile: 78Point, Part D claim volume, percentile in specialty: 48 · MIPS quality, percentile: 57Point, Part D claim volume, percentile in specialty: 45 · MIPS quality, percentile: 47Point, Part D claim volume, percentile in specialty: 37 · MIPS quality, percentile: 68Point, Part D claim volume, percentile in specialty: 7 · MIPS quality, percentile: 22Point, Part D claim volume, percentile in specialty: 70 · MIPS quality, percentile: 0Point, Part D claim volume, percentile in specialty: 8 · MIPS quality, percentile: 52Point, Part D claim volume, percentile in specialty: 25 · MIPS quality, percentile: 33Point, Part D claim volume, percentile in specialty: 98 · MIPS quality, percentile: 70Point, Part D claim volume, percentile in specialty: 22 · MIPS quality, percentile: 38Point, Part D claim volume, percentile in specialty: 55 · MIPS quality, percentile: 50Point, Part D claim volume, percentile in specialty: 95 · MIPS quality, percentile: 8Point, Part D claim volume, percentile in specialty: 23 · MIPS quality, percentile: 92Point, Part D claim volume, percentile in specialty: 100 · MIPS quality, percentile: 20Point, Part D claim volume, percentile in specialty: 53 · MIPS quality, percentile: 30Point, Part D claim volume, percentile in specialty: 40 · MIPS quality, percentile: 92Point, Part D claim volume, percentile in specialty: 13 · MIPS quality, percentile: 67Point, Part D claim volume, percentile in specialty: 65 · MIPS quality, percentile: 12Point, Part D claim volume, percentile in specialty: 27 · MIPS quality, percentile: 17Point, Part D claim volume, percentile in specialty: 68 · MIPS quality, percentile: 40Point, Part D claim volume, percentile in specialty: 67 · MIPS quality, percentile: 13Point, Part D claim volume, percentile in specialty: 10 · MIPS quality, percentile: 88Point, Part D claim volume, percentile in specialty: 93 · MIPS quality, percentile: 43Point, Part D claim volume, percentile in specialty: 62 · MIPS quality, percentile: 92Point, Part D claim volume, percentile in specialty: 43 · MIPS quality, percentile: 35Point, Part D claim volume, percentile in specialty: 73 · MIPS quality, percentile: 75Point, Part D claim volume, percentile in specialty: 42 · MIPS quality, percentile: 32Point, Part D claim volume, percentile in specialty: 57 · MIPS quality, percentile: 42Point, Part D claim volume, percentile in specialty: 17 · MIPS quality, percentile: 45Point, Part D claim volume, percentile in specialty: 15 · MIPS quality, percentile: 55Point, Part D claim volume, percentile in specialty: 80 · MIPS quality, percentile: 10Point, Part D claim volume, percentile in specialty: 10 · MIPS quality, percentile: 83Point, Part D claim volume, percentile in specialty: 75 · MIPS quality, percentile: 27Point, Part D claim volume, percentile in specialty: 50 · MIPS quality, percentile: 92Point, Part D claim volume, percentile in specialty: 97 · MIPS quality, percentile: 92Point, Part D claim volume, percentile in specialty: 5 · MIPS quality, percentile: 58Point, Part D claim volume, percentile in specialty: 0 · MIPS quality, percentile: 87Point, Part D claim volume, percentile in specialty: 90 · MIPS quality, percentile: 72Point, Part D claim volume, percentile in specialty: 2 · MIPS quality, percentile: 73Point, Part D claim volume, percentile in specialty: 92 · MIPS quality, percentile: 48Point, Part D claim volume, percentile in specialty: 85 · MIPS quality, percentile: 28Point, Part D claim volume, percentile in specialty: 72 · MIPS quality, percentile: 15Point, Part D claim volume, percentile in specialty: 38 · MIPS quality, percentile: 53Point, Part D claim volume, percentile in specialty: 82 · MIPS quality, percentile: 85Point, Part D claim volume, percentile in specialty: 78 · MIPS quality, percentile: 65Point, Part D claim volume, percentile in specialty: 3 · MIPS quality, percentile: 77Point, Part D claim volume, percentile in specialty: 33 · MIPS quality, percentile: 60Point, Part D claim volume, percentile in specialty: 83 · MIPS quality, percentile: 7Point, Part D claim volume, percentile in specialty: 47 · MIPS quality, percentile: 18Point, Part D claim volume, percentile in specialty: 87 · MIPS quality, percentile: 0Glen O'Sullivan, M.D., Part D claim volume, percentile in specialty: 68 · MIPS quality, percentile: 50
Part D claim volume vs MIPS quality, by specialty percentile

Each dot is one specialist peer from a representative sample of 60; the gold marker is Glen O'Sullivan, M.D.. Source: CMS Medicare Part D Prescriber data and the CMS Merit-based Incentive Payment System, 2023.

What does the federal data show about Glen O'Sullivan, M.D.?

Near national average

NPI registry status

Active

Issued 08/03/2005

NPI 1972504652

Primary specialty

Specialist

High-volume

69,608 US NPIs in this specialty

Medicare Part D claims

1,633 11% vs specialty avg

2023 prescription claims

Specialty avg: 1,474

MIPS final score

83.8/100 0.3 pts vs avg

Above neutral band

vs 83.5 national avg

Specialty distribution in California

How Specialist compares to other specialties among California providers

California providers
Behavior Technician17.3%Marriage & Family Therapist5.5%Student in an Organized Heal…5%Mental Health Counselor3.9%Pharmacist3.5%Clinical Social Worker3.1%Specialist0.7%
Largest specialties in California (% of in-state providers)

Medicare quality performance, MIPS

Glen O'Sullivan, M.D.'s 2023 MIPS final score plotted against the Specialist national average

Near national average
MIPS Final Score
83.8/100
vs 83.5 national avg · 2023 performance year
0%100%National avg84%83.8%
MIPS final score (Specialist) - 83.8/100 vs national avg 83.5
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

635 LASSEN LN
Mount Shasta, CA 96067
(866) 668-3597

Provider Details

NPI 1972504652
Specialty Specialist
Credentials M.D.
Gender Male
NPI Issued 08/03/2005

CMS Quality Score (MIPS)

Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.

83.7853
Final Score
Measured-score avg: 83.5
82.0863
Quality
63.8646
Cost
100
Promoting Interoperability

Reporting: Group practice

Industry payments received (2024) - CMS Open Payments transparency data

The federal Physician Payments Sunshine Act (part of the Affordable Care Act) requires drug and medical-device manufacturers + group purchasing organizations to publicly report payments and other transfers of value to physicians and teaching hospitals. The data below covers 2024 for Glen O'Sullivan, M.D.. Source: openpaymentsdata.cms.gov.

Total received

$18

Largest payer

VERTEX PHARMACEUTICALS INCORPORATED

Most common payment type

Food and Beverage

Industry payments are not necessarily indicators of bias, they include research funding, consulting fees for evidence-based work, royalties for inventions, food at conferences, and similar items. The disclosure exists for transparency. Read our methodology for how we interpret this data.

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 Glen O'Sullivan, M.D.. To verify Glen O'Sullivan, M.D.'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.

Medicare Part D Prescribing Data

CMS Medicare Part D prescriber-level data for calendar year 2023.

1,633
Total Claims
$29K
Total Drug Cost
466
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
2,173
Total Day Supply
51,148
Generic Drug Cost
$27K
Opioid Claims
274 (16.8% rate)
Antibiotic Claims
25

Patient Demographics

Average Patient Age
72.7 years
Avg HCC Risk Score
0.99
Gender Split
57% female / 43% male
Age Distribution
<65: 52, 65-74: 219, 75-84: 171, 85+: 24

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

What Glen O'Sullivan, M.D. prescribes most

Top Medicare Part D drugs by claim count, 2023

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
Drug Claims
Gabapentin
 311
Celecoxib
 267
Meloxicam
 189
Methylprednisolone
 139
Cyclobenzaprine Hcl
 135
Oxycodone Hcl
 123
Diazepam
 90
Hydrocodone-Acetaminophen
Hydrocodone/Acetaminophen
55
Pregabalin
 48
Methocarbamol
 39

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

More Specialist in CA → All providers in California → Compare specialties →

Specialist Overview

How Glen O'Sullivan, M.D. fits within the Specialist landscape nationally.

69,608
Specialist Providers in US
55
States with Specialist
1,474
Avg Claims per Provider

Glen O'Sullivan, M.D.'s 1,633 claims are above the specialty average of 1,474.

Nationwide Specialist peers with similar MIPS or enrollment year

Two federal-record peer sets for O'Sullivan, both outside California so the neighborhoods are not geographic containment.

Similar MIPS final score

Nearest same-specialty clinicians by CMS MIPS final score (83.8 here).

James Loos 83.8 OR Susan Dausch 83.8 VA Victoria Davis 83.8 VA Lea Mahoney 83.8 VA

Same NPPES enumeration year (2005)

Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.

Jacqueline Carruthers Houston, TX K Reichard Louisville, KY Stephen Katz Alexandria, LA John Baer Colorado Springs, CO

Nearby Specialist Providers in California

Other clinicians with the same primary specialty enrolled in California, drawn from the same CMS NPPES roster as O'Sullivan.

One of 6,672 Specialist providers enrolled in California, 5 are shown here.

Adrienne Abad Santos
San Francisco, CA
Dr. Brenda Abarca
MD
Torrance, CA
Dr. Fatemeh Abbasi
PT
Van Nuys, CA
Dr. Erlinda Abcede
M.D.
Cudahy, CA
Dr. Maher Abdallah
M.D.
Palm Springs, CA

Compare Specialist nationally: see state-by-state distribution →

Frequently Asked Questions

What is Glen O'Sullivan, M.D.'s specialty? ▼
Glen O'Sullivan, M.D. specializes in Specialist and practices in Mount Shasta, California. Credentials: M.D..
How much does Glen O'Sullivan, M.D. prescribe under Medicare Part D? ▼
In 2023, Glen O'Sullivan, M.D. wrote 1,633 Medicare Part D claims totaling $29K in drug costs for 466 beneficiaries.
What is Glen O'Sullivan, M.D.'s Medicare quality score? ▼
Glen O'Sullivan, M.D. has a CMS MIPS Final Score of 83.8/100 (Quality: 82.1, Cost: 63.9). The average MIPS Final Score across the 454,083 clinicians with at least one published category score is 83.5; clinicians whose score CMS assigned without scoring any category are excluded from that average. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is Glen O'Sullivan, M.D. located? ▼
Glen O'Sullivan, M.D. is located at 635 LASSEN LN, Mount Shasta, CA, 96067. Phone: (866) 668-3597.
What is Glen O'Sullivan, M.D.'s NPI number? ▼
Glen O'Sullivan, M.D.'s National Provider Identifier (NPI) is 1972504652, issued on 08/03/2005.
Does Glen O'Sullivan, M.D. prescribe opioids? ▼
Yes, Glen O'Sullivan, M.D. had 274 opioid claims in 2023 with an opioid prescribing rate of 16.8%.
How many Specialist providers are there in the US? ▼
There are 69,608 Specialist providers across 55 states in the US. The average Specialist provider writes 1,474 Medicare Part D claims per year.
What drugs does Glen O'Sullivan, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Glen O'Sullivan, M.D.'s most frequently prescribed drugs include Gabapentin, Celecoxib, Meloxicam. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Glen O'Sullivan, M.D. accept Medicare? ▼
Glen O'Sullivan, M.D. appears in CMS Medicare data with 1,633 Part D claims and 466 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Glen O'Sullivan, M.D.'s credentials? ▼
Glen O'Sullivan, M.D.'s NPI is 1972504652 with credentials M.D.. 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.
Quality Performance
CMS Merit-based Incentive Payment System (MIPS) - 2023 performance year.
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

Compiled from official public sources by the editorial process.

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.