DR. MATHIAS A. MASEM M.D.
NPI 1508810938
Orthopaedic Surgery - Hand Surgery in Oakland, CA

Q: What is Mathias Masem's NPI number?

The NPI number for Mathias Masem is 1508810938. It was assigned to this individual provider in the NPPES registry on May 20, 2006.

Q: What is Mathias Masem's specialty?

The primary specialty registered for this NPI is Orthopaedic Surgery, specializing in Hand Surgery, with taxonomy code 207XS0106X.

Q: When was this NPI record last updated?

The NPPES record for Mathias Masem was last updated on December 18, 2014. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 11 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.

Active since May 20, 2006PECOS EnrolledAccepts Medicare Assignment

79.23/100

CMS Quality Rating

80 GRAND AVE, SUITE 600, OAKLAND, CA 94612(510) 763-0884(510) 763-1574 Get Directions Write a Review

NPPES record last updated: December 18, 2014. Verified against the NPPES registry weekly; last sync: October 18, 2026.

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About Dr. Mathias A. Masem M.d. NPPES

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

DR. MATHIAS A. MASEM M.D. (NPI 1508810938) is an individual hand surgery provider in Oakland, California, licensed in California (G34134) and active in the NPI registry since May 2006. He is enrolled in Medicare PECOS and is a graduate of University Of Minnesota Medical School (1975).

NPPES Registry Identity

NPI1508810938

Entity TypeIndividualMale

Primary Taxonomy207XS0106X

Provider Legal NameDR. MATHIAS A. MASEMCredential: M.D.

Location Address80 GRAND AVE, SUITE 600Oakland, CA 94612-3744

Mailing Address80 Grand Ave, Suite 600Oakland, CA 94612-3744 · (510) 763-0884 · Fax (510) 763-1574

Phone(510) 763-0884

Fax(510) 763-1574

Sole ProprietorYes

Medical School CMSUniversity Of Minnesota Medical SchoolGraduated 1975

Enumeration DateMay 20, 2006

Last NPPES UpdateDecember 18, 2014

✔ NPI 1508810938 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyOrthopaedic Surgery · Hand SurgeryAllopathic & Osteopathic Physicians

Taxonomy Code207XS0106X

License✔ Licensed in CA · G34134

Definition

An orthopaedic surgeon trained in the investigation, preservation and restoration by medical, surgical and rehabilitative means of all structures of the upper extremity directly affecting the form and function of the hand and wrist.

Also ListedOrthopaedic SurgeryTaxonomy 207X00000X · License G34134 (CA)

80 GRAND AVE, Oakland, CA 94612

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Other Identifiers 4

Medicare UPINA45795CA

Medicare NSC6031100001CA

Medicaid00G341340CA

Medicare PIN00G341340CA

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. Mathias A. Masem 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 ID8820026438

PECOS Enrollment IDI20050803000637

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 Reassignments

Medicare enrollment records show Mathias Masem reassigns Medicare billing to 5 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Mathias Masem, M.D.

Same address

Specialist

80 GRAND AVE.,, SUITE 600
Oakland, CA 94612

Reassigned Medicare billing, California enrollment
Medicare enrollment name: Mathias Masem MD
3 clinicians in this Medicare group

NPI 1457371643 (510) 763-0709

City & County Of San Francisco

7.6 mi

Primary Care

760 HARRISON ST
San Francisco, CA 94107

Reassigned Medicare billing, California enrollment
1,573 clinicians in this Medicare group

NPI 1568923894 (415) 836-1700

University Of California Sfgh Medical Group

8.6 mi

Podiatrist

2540 23RD STREET, BUILDING 7, 3RD FLOOR
San Francisco, CA 94110

Reassigned Medicare billing, California enrollment
81 clinicians in this Medicare group

NPI 1700057908 (415) 476-2124

University Of California San Francisco

11 mi

Surgery

400 PARNASSUS AVE, MCB 300
San Francisco, CA 94143

Reassigned Medicare billing, California enrollment
5,645 clinicians in this Medicare group

NPI 1346329380 (415) 353-2161

Ucsf Medical Group Business Services

11 mi

Internal Medicine

400 PARNASSUS AVE
San Francisco, CA 94122

Reassigned Medicare billing, California enrollment
5,544 clinicians in this Medicare group

NPI 1477624104 (415) 353-2808

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 12

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.

Injection, triamcinolone acetonide, not otherwise specified, 10 mg J3301

Triamcinolone acetonide is a medication used to reduce inflammation in the body. It's given as a 10 mg injection for conditions like allergies, arthritis, or skin problems. The injection helps to decrease swelling, redness, and itching.

296 services41 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.

251 services141 patients

Injection, betamethasone acetate 3 mg and betamethasone sodium phosphate 3 mg J0702

This injection contains two medications, betamethasone acetate and betamethasone sodium phosphate. It is used to reduce inflammation and pain. It's given by a healthcare professional, often directly into the area causing discomfort.

109 services35 patients

Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213

This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.

92 services69 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.

76 services76 patients

Aspiration and/or injection of fluid from small joint using ultrasound guidance 20604

This procedure involves using ultrasound to accurately locate a small joint. A needle is then carefully inserted to remove fluid (aspiration) or inject medication. This can help diagnose or treat joint issues. It's generally safe and minimally invasive.

59 services42 patients

X-ray of hand, minimum of 3 views 73130

An X-ray of the hand, minimum of 3 views, is a non-invasive imaging test. It uses a small amount of radiation to produce images of the bones in your hand from different angles. This helps in diagnosing fractures, infections, arthritis, or other abnormalities. It's quick and painless.

49 services32 patients

X-ray of wrist, minimum of 3 views 73110

An X-ray of the wrist, minimum of 3 views, is a diagnostic procedure that uses radiation to create images of your wrist from different angles. This helps detect fractures, infections, or other abnormalities for accurate diagnosis and treatment planning.

48 services28 patients

Aspiration and/or injection of fluid from medium joint using ultrasound guidance 20606

This is a procedure where a needle is guided by ultrasound into a medium-sized joint, like a knee or shoulder. The needle can be used to remove fluid, which can relieve pressure and pain, or to inject medication to help with inflammation and discomfort.

20 services18 patients

X-ray of finger, minimum of 2 views 73140

An X-ray of the finger involves capturing images of your finger from at least two different angles. This non-invasive procedure helps in visualizing the bones and joints, aiding in the diagnosis of fractures, infections, or other abnormalities. Minimal discomfort may be experienced.

17 services17 patients

Release of wrist ligament using an endoscope 29848

This procedure involves using a small camera, called an endoscope, to view and treat a tight wrist ligament. The endoscope is inserted through a tiny incision, reducing recovery time and scarring. It helps to relieve pain and improve wrist function.

16 services16 patients

Aspiration and/or injection of fluid from medium joint 20605

This procedure involves a needle being inserted into a medium-sized joint, such as a knee or shoulder, to remove (aspirate) excess fluid. Sometimes, medication may also be injected into the joint to reduce inflammation and pain.

15 services14 patients

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 94612 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient

$104.51 typical visit price

range $69.00 – $202.35

Typical copayment $26.12 (range $17.25 – $50.58)

Most-billed visit code 99203

Established Patient

$84.91 typical visit price

range $23.44 – $166.46

Typical copayment $21.22 (range $5.86 – $41.61)

Most-billed visit code 99213

Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Medicare Quality Performance CMS QPP · MIPS

Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.

79.23/100

MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program

Scored as part of a group practice

Quality

62.23

Promoting Interoperability

100

Improvement Activities

Reported Quality Measures

Breast Cancer Screening

88%25 patients4/55-star benchmark: 93%

Cervical Cancer Screening

31%295 patients2/55-star benchmark: 98%

Closing the Referral Loop: Receipt of Specialist Report

0%509 patients1/55-star benchmark: 87%

Colorectal Cancer Screening

39%51 patients2/55-star benchmark: 88%

Controlling High Blood Pressure

48%25 patients3/55-star benchmark: 91%

Diabetes: Eye Exam

13%48 patients1/55-star benchmark: 100%

Diabetes: Hemoglobin A1c (HbA1c) Poor Control (>9%)

Lower rates are better for this measure.

35%48 patients3/55-star benchmark: 91%

Documentation of Current Medications in the Medical Record

74%110 patients3/55-star benchmark: 100%

e-Prescribing

93%483 patients2/55-star benchmark: 100%

Falls: Screening for Future Fall Risk

0%254 patients1/55-star benchmark: 100%

Preventive Care and Screening: Body Mass Index (BMI) Screening and Follow-Up Plan

30%83 patients2/55-star benchmark: 98%

Preventive Care and Screening: Screening for Depression and Follow-Up Plan

3%62 patients1/55-star benchmark: 97%

Preventive Care and Screening: Screening for High Blood Pressure and Follow-Up Documented

0%1,820 patients1/55-star benchmark: 61%

Preventive Care and Screening: Tobacco Use: Screening and Cessation Intervention

Patients combinedPopulations: 96% · 23 patients

Patients screened: 96% · 23 patients

10%39 patients1/55-star benchmark: 100%

Provide Patients Electronic Access to Their Health Information

100%84 patients5/55-star benchmark: 100%

Use of High-Risk Medications in Older Adults

Lower rates are better for this measure.

Patients appropriateDiagnosis: 4% · 278 patients

Patients totalRate: 5% · 278 patients

4%278 patients4/55-star benchmark: 100%

Providers report different measures because they deliver different services; reporting more or less information is not a reflection of quality. Star ratings appear only where CMS assigned them.

Other Providers at the Same Location NPPES 18

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

JEFFREY ADAM MANN, M. D., INC.

Orthopaedic Surgery

80 GRAND AVE, 5TH FLOOR
OAKLAND, CA 94612

Alameda County (510) 451-6266

DR. GLEN K. LAU M.D.

Plastic Surgery

80 GRAND AVE, STE. 810
OAKLAND, CA 94612

Alameda County (510) 451-6950

GLEN KEE LAU, MD INC

Plastic Surgery

80 GRAND AVE, STE. 810
OAKLAND, CA 94612

Alameda County (510) 451-6950

SARAH LANGBEIN PA

Physician Assistant

80 GRAND AVE
OAKLAND, CA 94612

Alameda County (510) 238-1200

XIANG FEI LAC

Case Manager/Care Coordinator

80 GRAND AVE, SUITE 610
OAKLAND, CA 94612

Alameda County (510) 835-0235

DR. STEVEN GRAY PASCAL M.D.

Ophthalmology

80 GRAND AVE, SUITE 700
OAKLAND, CA 94612

Alameda County (510) 893-4318

WEBSTER SURGERY CENTER, LP

Clinic/Center (Ambulatory Surgical)

80 GRAND AVE, SUITE 250
OAKLAND, CA 94612

Alameda County (510) 451-1875

OAKLAND SLEEP CENTER

Clinic/Center (Sleep Disorder Diagnostic)

80 GRAND AVE, SUITE 200
OAKLAND, CA 94612

Alameda County (510) 350-4030

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 Mathias Masem's NPI number?

The NPI number for Mathias Masem is 1508810938. It was assigned to this individual provider in the NPPES registry on May 20, 2006.

Where is Mathias Masem located?

Mathias Masem practices at 80 Grand Ave Suite 600, Oakland, CA 94612. The listed phone number is (510) 763-0884.

What is Mathias Masem's specialty?

The primary specialty registered for this NPI is Orthopaedic Surgery, specializing in Hand Surgery, with taxonomy code 207XS0106X.

Is Mathias Masem enrolled in Medicare?

Yes. Mathias Masem 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 organizations bill Medicare for Mathias Masem's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Mathias Masem reassigns Medicare benefits to 5 organizations: Mathias Masem, M.D. (Oakland, CA), City & County Of San Francisco (San Francisco, CA), University Of California Sfgh Medical Group (San Francisco, CA), University Of California San Francisco (San Francisco, CA) and Ucsf Medical Group Business Services (San Francisco, CA). Each 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 Mathias Masem'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 Mathias Masem was last updated on December 18, 2014. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 11 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.