Glen S. O'Sullivan, M.D.
Specialist · Mount Shasta, CA
Glen S. O'Sullivan, M.D. is a specialist with a practice address in Mount Shasta, California, and NPI 1972504652, issued on Aug 3, 2005. Check the license (California A44219, as entered in NPPES) with the California board that licenses this profession; the Medicare figures below come from public CMS files.
- Name
- Glen S. O'Sullivan
- Credential
- M.D.
- Primary taxonomy
- Specialist 174400000X
- License number
- A44219 CA
Self-reported in NPPES; status is on the state search - Practice location
- 635 Lassen LN, Mount Shasta, CA 96067
- Phone
- (866) 668-3597
- Enumerated
- Aug 3, 2005
- Record last updated
- Nov 23, 2010 (not updated in 16 years: call before relying on the address or phone)
- Fax
- (866) 301-6641
- Medicare enrollment
- Enrolled (PECOS I20070402000375); accepts Medicare assignment
- Telehealth
- Offers telehealth (CMS)
- Entity
- Type 1 · individual
8 nearest specialist records → All 5,749 in California → Look up another NPI →
Also registered at 635 Lassen LN
A shared address usually means a shared clinic or building; it does not show who employs whom.
- Todd Guthrie, M.D.Orthopaedic Surgery Physician1871555334
Verify Glen S. O'Sullivan in five checks
- 1IdentityNPI record in CMS NPPESNPI lookupConfirmed in NPPES
- 2LicenseActive license and public ordersWhich California board licenses this profession
Search for license A44219Check the board - 3Other statesLicenses and actions elsewhereDocInfo (FSMB)Not checked
- 4ExclusionsMedicare and Medicaid bansHHS-OIG exclusion listNot checked
- 5CertificationBoard certificationABMS AOA NCCPA AANPNot checked
37% more Medicare Part D claims than the average specialist in 2024
1,896 Medicare Part D claims for 481 beneficiaries, against an average of 1,380 among the 8,233 providers of this specialty who prescribed in Part D. Brand-name drugs were under 1% of claims. 302 claims were for opioids.
Most prescribed
- Gabapentin338 claims
- Celecoxib328 claims
- Meloxicam212 claims
- Cyclobenzaprine Hcl184 claims
- Oxycodone Hcl176 claims
- Methylprednisolone157 claims
Source: CMS Medicare Part D Prescribers by Provider and Drug, 2024 (data.cms.gov). Part D covers prescriptions for Medicare patients only; drugs with fewer than 11 claims are not published.
The practice group's MIPS final score for 2023 (Medicare payment program): 83.8 of 100
The Merit-based Incentive Payment System score is reported for the practice group, not for one clinician alone. Four categories are weighted into the final score; the average among 454,083 clinicians with a measured score was 83.5.
Source: CMS Quality Payment Program, MIPS performance year 2023, group reporting; category weights for 2023 (qpp.cms.gov).
Industry payments in 2024: $17.85
1 payment: food and beverage; the largest payer was Vertex Pharmaceuticals Incorporated. The 5,844 providers of this specialty with any payment received $4,760.79 on average. Payments are reported by manufacturers, not by the provider, and are not a sign of wrongdoing.
Source: CMS Open Payments, program year 2024 (openpaymentsdata.cms.gov); average among providers of this specialty with at least one payment.
Glen S. O'Sullivan among 5,749 specialist records in California
Glen S. O'Sullivan, M.D. is one of 5,749 specialist records with a practice address in California. 30% of them appear in a Medicare file (Part D prescribing, MIPS, Open Payments or Medicare group billing); this one does. Its NPI, issued in 2005, is newer than 0% of them.
- NPI issued2005 · 0% of these records are older, 93% newer
- In a Medicare fileYes · 30% of these records are
- In the CMS Doctors and Clinicians fileYes · 19% of these records are
- Graduated1986 · median 1989 among the 1,075 with a school on file
- Record last updated2010 · 77% of these records were not updated in five years or more
Source: CMS NPPES, file of Aug 9, 2026, every record with primary taxonomy 174400000X and a California practice address; Medicare files: CMS Part D Prescribers 2024, MIPS 2023, Open Payments 2024, Doctors and Clinicians (data.cms.gov).
Specialist providers in California
There are 5,749 specialist records in California.
All 5,749 in California → Every provider in Mount Shasta → Specialist nationwide →
The 8 specialist records with the nearest ZIP codes
- Nestor CamarilloRed Bluff, CA 960801194146712
- Stephen Datu, MDRed Bluff, CA 960801386746287
- Samantha SchlieterYreka, CA 960971407568116
- Tony Vasquez, M.D.,PH.D.Yreka, CA 960971477524197
- Peggy ClevingerAlturas, CA 961011467133124
- Gregory Kuld, BA, MA, MAAlturas, CA 961011881241503
- Sarah UrbanAlturas, CA 961011952114480
- Steven Brown, MS PTChester, CA 960201124121413
Common questions
What is Glen S. O'Sullivan, M.D.'s NPI number?
Glen S. O'Sullivan, M.D.'s National Provider Identifier (NPI) is 1972504652, issued on Aug 3, 2005. An NPI identifies a provider in billing; it is not a license.
Where is Glen S. O'Sullivan, M.D. located?
The NPPES record lists a practice address at 635 Lassen LN, Mount Shasta, CA, 96067. Phone: (866) 668-3597. Providers update this record themselves, so call before visiting.
How can I verify Glen S. O'Sullivan, M.D.'s license?
NPPES lists California license number A44219, as entered by the provider. Search the California board that licenses this profession; the NPPES record confirms identity only.
How much does Glen S. O'Sullivan, M.D. prescribe under Medicare Part D?
In 2024, Glen S. O'Sullivan, M.D. had 1,896 Medicare Part D claims for 481 beneficiaries; the average among specialist prescribers was 1,380. Part D covers Medicare prescriptions only.
What is Glen S. O'Sullivan, M.D.'s MIPS final score?
The 2023 MIPS final score is 83.8 of 100, reported for the practice group. The average among 454,083 clinicians with a measured score was 83.5.
Source: CMS National Plan and Provider Enumeration System (NPPES), file of Aug 9, 2026 (NPPES files on CMS.gov); NUCC Health Care Provider Taxonomy. Medicare files from data.cms.gov. An NPI identifies who bills; it is not a license.
Figures on PlainDoctor are read from the federal files each page names (CMS NPPES, Medicare Part D, MIPS, Open Payments; the HHS-OIG exclusion list only as counts) and from Census population estimates, with the file date shown beside them. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of Aug 9, 2026.