DR. ARI D BARON M.D.
NPI 1013086420
Specialist in San Francisco, CA

Q: What is Ari Baron's NPI number?

The NPI number for Ari Baron is 1013086420. It was assigned to this individual provider in the NPPES registry on November 7, 2006.

Q: What is Ari Baron's specialty?

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

Q: When was this NPI record last updated?

The NPPES record for Ari Baron was last updated on July 8, 2007. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 19 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 November 07, 2006PECOS EnrolledAccepts Medicare Assignment

100/100

CMS Quality Rating

2100 WEBSTER STREET SUITE 225, SAN FRANCISCO, CA 94115(415) 923-3012 Get Directions Write a Review

NPPES record last updated: July 8, 2007. Verified against the NPPES registry weekly; last sync: November 01, 2026.

On this page

About Dr. Ari D Baron M.d. NPPES

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

DR. ARI D BARON M.D. (NPI 1013086420) is an individual specialist in San Francisco, California, licensed in California (G72619) and active in the NPI registry since November 2006. He is enrolled in Medicare PECOS and is a graduate of Tufts University School Of Medicine (1990).

NPPES Registry Identity

NPI1013086420

Entity TypeIndividualMale

Primary Taxonomy174400000X

Provider Legal NameDR. ARI D BARONCredential: M.D.

Location Address2100 WEBSTER STREET SUITE 225San Francisco, CA 94115

Mailing Address2100 Webster Street Suite 225San Francisco, CA 94115 · (415) 923-3012

Phone(415) 923-3012

Sole ProprietorNo

Medical School CMSTufts University School Of MedicineGraduated 1990

Enumeration DateNovember 7, 2006

Last NPPES UpdateJuly 8, 2007

✔ NPI 1013086420 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtySpecialistOther Service Providers

Taxonomy Code174400000X

License✔ Licensed in CA · G72619

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.

2100 WEBSTER STREET SUITE 225, San Francisco, CA 94115

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Other Identifiers 3

Medicare ID-Type Unspecified00G726190CA

Medicare UPINF31464CA

MedicaidYYY49266YCA

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. Ari D Baron 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 ID8325107907

PECOS Enrollment IDI20081111000873

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 Ari Baron reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Pacific Hematology Oncology Assoc

Same address

Specialist

2100 WEBSTER ST, 225
San Francisco, CA 94115

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

NPI 1073630406 (415) 923-3876

Sutter Bay Medical Foundation

15 mi

Multi-Specialty

12 CAMINO ENCINAS
Orinda, CA 94563

Reassigned Medicare billing, California enrollment
4,479 clinicians in this Medicare group

NPI 1366898538 (510) 204-8180

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 40

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, darbepoetin alfa, 1 microgram (non-esrd use) J0881

Darbepoetin alfa injection is a medication used to treat anemia (low red blood cell count) often caused by chronic kidney disease or chemotherapy. It works by stimulating your body to produce more red blood cells, helping to increase your energy and well-being.

20,228 services28 patients

Injection, ferumoxytol, for treatment of iron deficiency anemia, 1 mg (non-esrd use) Q0138

Ferumoxytol injection is a treatment for iron deficiency anemia, a condition where your body lacks enough iron. It is injected into your vein to increase iron levels, aiding in the production of healthy red blood cells. This treatment is not for ESRD patients.

19,380 services22 patients

Injection, oxaliplatin, 0.5 mg J9263

Oxaliplatin is a chemotherapy drug that is administered via injection. It works by stopping cancer cells from growing and dividing, which helps in the treatment of certain types of cancer. The dosage is 0.5 mg, and it's important to follow your doctor's instructions for this treatment.

9,501 services12 patients

Injection, denosumab, 1 mg J0897

Denosumab is a medication given via injection to strengthen your bones. It works by slowing down the cells that break down bone, improving bone density and reducing the risk of fractures. It's often used for osteoporosis treatment.

9,163 services50 patients

Injection, pembrolizumab, 1 mg J9271

Pembrolizumab is a medication given via injection to help your body's immune system fight certain types of cancer. It's typically administered in a hospital or clinic by a healthcare professional.

8,815 services15 patients

Injection, nivolumab, 1 mg J9299

Nivolumab is a medication given via injection, often used in cancer treatment. It works by helping your immune system fight the cancer cells. The dosage is measured in milligrams (mg), with 1 mg being a common dose.

7,902 services11 patients

Injection, dexamethasone sodium phosphate, 1 mg J1100

Dexamethasone sodium phosphate is a medication given via injection. It is a type of steroid that helps reduce inflammation and immune responses. It can be used to treat a variety of conditions, such as allergies, skin conditions, arthritis, and more.

2,835 services55 patients

Injection, palonosetron hcl, 25 mcg J2469

Palonosetron HCL is an injection used to prevent nausea and vomiting caused by chemotherapy. It works by blocking a natural substance (serotonin) in the body that can cause vomiting. This helps improve your comfort during cancer treatment.

2,098 services54 patients

Injection, leucovorin calcium, per 50 mg J0640

Leucovorin calcium is an injection given to enhance the effectiveness of certain cancer treatments or to reduce the harmful effects of some medications. The dose is determined by your doctor and is typically administered in a healthcare setting.

1,181 services19 patients

Injection, fluorouracil, 500 mg J9190

Fluorouracil is a chemotherapy drug, given as an injection to treat various types of cancer. The 500 mg dose helps to stop cancer cells from growing and multiplying. You might feel some side effects, but these are typically manageable.

1,036 services23 patients

Complete blood cell count (red cells, white blood cell, platelets), automated test and automated differential white blood cell count 85025

A Complete Blood Cell Count is a common test that measures various components of the blood, including red cells (carry oxygen), white cells (fight infection), and platelets (help blood clot). An automated test ensures accuracy. The differential count provides detailed information about white cell types.

975 services200 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.

917 services434 patients

Administration of chemotherapy into vein, 1 hour or less 96413

Chemotherapy is a treatment that uses drugs to destroy cancer cells. When administered into a vein, it's often through an IV. This procedure usually lasts 1 hour or less. You may feel a slight pinch as the needle is inserted, but it's generally painless.

456 services85 patients

Injection of drug or substance under skin or into muscle 96372

This procedure involves administering medication directly under the skin or into a muscle. A small needle is used to inject the drug, allowing it to be absorbed quickly into the bloodstream. It's a common method for delivering a variety of medications.

454 services109 patients

Injection, pegfilgrastim-cbqv (udenyca), biosimilar, 0.5 mg Q5111

Pegfilgrastim-cbqv (Udenyca) is a medication given via injection to stimulate the growth of white blood cells, which help your body fight infections. It's often used for patients undergoing certain types of chemotherapy.

425 services19 patients

Injection, gemcitabine hydrochloride, not otherwise specified, 200 mg J9201

Gemcitabine hydrochloride is a medication given via injection to treat certain types of cancer. The 200 mg dose is administered by a healthcare professional. The drug works by slowing or stopping the growth of cancer cells in the body. It's important to follow your doctor's instructions while receiving this treatment.

331 services12 patients

Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more 99215

This service involves a follow-up appointment for existing patients, lasting between 40 to 54 minutes. During this time, your healthcare provider will assess your current health status, discuss any changes or concerns, review your treatment plan, and answer any questions you may have.

297 services164 patients

Injection of additional new drug or substance into vein 96375

This procedure involves introducing a new medication or substance into your bloodstream via a vein. It's typically done using a small needle. The substance can help treat various conditions or assist in diagnostic procedures. It's generally safe and monitored by professionals.

289 services60 patients

Administration of additional new drug or substance into vein, 1 hour or less 96417

This procedure involves introducing a new drug or substance into your vein, typically via an IV drip. It lasts for an hour or less. This method allows the substance to quickly reach your bloodstream, ensuring rapid and effective treatment.

230 services42 patients

Leuprolide acetate (for depot suspension), 7.5 mg J9217

Leuprolide acetate is a medication that helps regulate certain hormone levels in your body. It's injected into your muscle once a month. This treatment can help manage various health conditions related to hormone imbalance. Always follow your doctor's instructions.

223 services48 patients

Administration of chemotherapy into vein, each additional hour 96415

Chemotherapy is a treatment method that uses drugs to destroy cancer cells. The drugs are administered into a vein, usually in the arm. Each additional hour of chemotherapy allows for more of the medication to enter your bloodstream to fight against the cancer cells.

192 services28 patients

Infusion into a vein for therapy, prevention, or diagnosis, additional sequential infusion, 1 hour or less 96367

This procedure involves injecting fluids or medication directly into your vein. It's used for treatment, prevention, or diagnosis. An additional sequential infusion may be given within an hour if needed. This helps to ensure the medicine is distributed effectively in your body.

181 services46 patients

Administration of hormonal anti-neoplastic chemotherapy under skin or into muscle 96402

This procedure involves the injection of hormone-based anti-cancer drugs under the skin or into a muscle. These medications help to slow down or stop the growth of certain types of cancer cells. The process is usually quick and can be performed in a clinic or hospital.

145 services51 patients

Administration of non-hormonal anti-neoplastic chemotherapy under skin or into muscle 96401

This procedure involves giving anti-cancer drugs, which don't contain hormones, into the muscle or under the skin. These drugs help to stop the growth of cancer cells. The process is usually quick and done by a healthcare professional.

144 services17 patients

Administration of prolonged chemotherapy into vein 96416

Chemotherapy is a treatment using drugs to destroy cancer cells. Prolonged chemotherapy into a vein involves the slow infusion of these drugs directly into your bloodstream over an extended period. This method ensures a continuous and effective dose to combat your cancer cells.

126 services21 patients

Infusion into a vein for therapy, prevention, or diagnosis concurrent with another infusion 96368

An infusion into a vein is a method of delivering medication, nutrients, or fluids directly into your bloodstream. If it's concurrent with another infusion, it means two different solutions are given at the same time. This can be for treatment, prevention, or diagnostic purposes.

94 services18 patients

Infusion into a vein for hydration, 31-60 minutes 96360

This is a procedure where a sterile solution is administered into your vein to help restore body fluid balance. It typically lasts between 31-60 minutes. It's a safe, common treatment for dehydration or to deliver medication.

68 services13 patients

Injection, diphenhydramine hcl, up to 50 mg J1200

Diphenhydramine HCL injection is a medicine given to alleviate symptoms of allergies, colds, or hay fever. It can also help with motion sickness and certain symptoms of Parkinson's disease. Up to 50 mg may be administered depending on your condition.

66 services21 patients

Application of on-body injector for under skin injection 96377

An on-body injector is a device used to deliver medication under the skin. It's applied to a clean area of skin, usually the abdomen or back of the arm. The device is activated to inject the medication slowly, ensuring a steady absorption. It's a painless, safe, and effective way to administer certain types of medication.

59 services15 patients

New patient office or other outpatient visit with a high level of medical decision making, if using time, 60 minutes or more 99205

This is a first-time patient visit where a healthcare professional spends 60-74 minutes with you. It involves a comprehensive evaluation, including your medical history and current health condition. They'll also advise on preventive health measures and formulate a treatment plan if needed.

56 services56 patients

Telephone medical discussion with physician, 21-30 minutes 99443

This service involves a 21-30 minute phone conversation with a physician. It's a chance for you to discuss your health concerns, symptoms or treatment plans. It's similar to an in-person consultation, but conducted over the phone for your convenience and safety.

47 services40 patients

Irrigation of implanted venous access drug delivery device 96523

Irrigation of an implanted venous access drug delivery device is a procedure to clean or unblock the device. This device is implanted under your skin to allow easy, frequent, and long-term access to your veins for medication delivery. The process involves flushing the device with a sterile solution to ensure it works properly.

40 services15 patients

Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 99233

Follow-up hospital inpatient care per day typically involves a 35-minute check-up by your healthcare provider. This service includes monitoring your health progress, adjusting your treatment plan if needed, and answering any questions you may have about your condition or care.

40 services20 patients

Injection of drug or substance into vein 96374

This procedure involves introducing a medication or substance directly into your vein using a syringe. It's a quick and efficient way to deliver treatment throughout your body. You might feel a small prick when the needle enters. It's generally safe and effective.

36 services21 patients

Drawing of blood for a medical problem 99195

Drawing blood is a simple procedure where a needle is inserted into a vein, usually in your arm, to collect a small sample. This sample helps in diagnosing any medical issues you may have. You might feel a small prick, but overall, it's a quick and safe process.

33 services16 patients

Injection, vitamin b-12 cyanocobalamin, up to 1000 mcg J3420

This is a procedure where a small dose of Vitamin B-12, also known as Cyanocobalamin, is injected into your body. This vitamin is essential for nerve function and the production of red blood cells. It's often used to treat vitamin B-12 deficiency.

29 services12 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.

25 services25 patients

Telephone medical discussion with physician, 5-10 minutes 99441

A telephone medical discussion with a physician is a brief, 5-10 minute call where you can discuss your health concerns. It's a convenient way to receive medical advice without needing to visit a clinic. It's important to prepare questions in advance to make the most of this time.

23 services18 patients

Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 99223

Initial hospital inpatient care per day, typically 70 minutes, refers to the daily medical service provided to patients admitted to the hospital. This includes a comprehensive evaluation, diagnosis, treatment plan, and monitoring of your health condition. It ensures your well-being during your hospital stay.

19 services19 patients

Telephone medical discussion with physician, 11-20 minutes 99442

This is a service where you have a phone conversation with your doctor for 11-20 minutes. It's used for discussing health concerns, reviewing test results, or managing ongoing conditions. It's a convenient way to receive medical advice without an in-person visit.

18 services15 patients

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.

100/100

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

Scored as part of a group practice

Quality

91.46

Improvement Activities

Reported Quality Measures

Care Plan

Percentage of patients aged 65 years and older who have an advance care plan or surrogate decision maker documented in the medical record that an advance care plan was discussed but the patient did not wish or was not able to name a surrogate decision maker…

70%587 patients3/55-star benchmark: 100%

Documentation of Current Medications in the Medical Record

Percentage of visits for patients aged 18 years and older for which the eligible professional or eligible clinician attests to documenting a list of current medications using all immediate resources available on the date of the encounter.

81%2,927 patients3/55-star benchmark: 100%

Medication Reconciliation

The MIPS eligible clinician performs medication reconciliation for at least one transition of care in which the patient is transitioned into the care of the MIPS eligible clinician.

95%229 patients4/55-star benchmark: 100%

Oncology: Medical and Radiation - Pain Intensity Quantified

Percentage of patient visits, regardless of patient age, with a diagnosis of cancer currently receiving chemotherapy or radiation therapy in which pain intensity is quantified

96%1,013 patients4/55-star benchmark: 100%

Oncology: Medical and Radiation - Plan of Care for Pain

Percentage of visits for patients, regardless of age, with a diagnosis of cancer currently receiving chemotherapy or radiation therapy who report having pain with a documented plan of care to address pain

96%27 patients4/55-star benchmark: 100%

Pain Assessment and Follow-Up

Percentage of visits for patients aged 18 years and older with documentation of a pain assessment using a standardized tool(s) on each visit AND documentation of a follow-up plan when pain is present

96%2,927 patients4/55-star benchmark: 100%

Patient-Specific Education

The MIPS eligible clinician must use clinically relevant information from CEHRT to identify patient-specific educational resources and provide access to those materials to at least one unique patient seen by the MIPS eligible clinician.

72%1,026 patients3/55-star benchmark: 100%

Pneumococcal Vaccination Status for Older Adults

Percentage of patients 65 years of age and older who have ever received a pneumococcal vaccine

84%597 patients4/55-star benchmark: 90%

Preventive Care and Screening: Influenza Immunization

Percentage of patients aged 6 months and older seen for a visit between October 1 and March 31 who received an influenza immunization OR who reported previous receipt of an influenza immunization

26%847 patients2/55-star benchmark: 88%

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

Percentage of patients aged 18 years and older who were screened for tobacco use one or more times within 24 months AND who received tobacco cessation intervention if identified as a tobacco user

Patients screenedForUse: 98% · 668 patients

Patients tobacco: 97% · 668 patients

100%25 patients5/55-star benchmark: 98%

Provide Patient Access

At least one patient seen by the MIPS eligible clinician during the performance period is provided timely access to view online, download, and transmit to a third party their health information subject to the MIPS eligible clinician's discretion to withhold…

46%1,026 patients2/55-star benchmark: 100%

Secure Messaging

For at least one unique patient seen by the MIPS eligible clinician during the performance period, a secure message was sent using the electronic messaging function of CEHRT to the patient (or the patient-authorized representative), or in response to a secure…

0%1,026 patients1/55-star benchmark: 79%

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.

Referred Medical Equipment & Supplies CMS DME claims 3

Durable medical equipment, devices and supplies this provider ordered from DME suppliers for patients, from Medicare fee-for-service claims.

Capecitabine, oral, 500 mg J8521

Treatment-Treatment - Miscellaneous · category RX029N

6 suppliers54 claims3,478 services$0.69 avg. paid by Medicare

Pharmacy supply fee for oral anti-cancer, oral anti-emetic or immunosuppressive drug(s); for the first prescription in a 30-day period Q0511

Treatment-Chemotherapy · category RH012N

6 suppliers40 claims40 services$18.44 avg. paid by Medicare

Pharmacy supply fee for oral anti-cancer, oral anti-emetic or immunosuppressive drug(s); for a subsequent prescription in a 30-day period Q0512

Treatment-Chemotherapy · category RH012N

3 suppliers15 claims15 services$11.78 avg. paid by Medicare

Dollar amounts are the average Medicare paid the supplier per service. They are not the cost to the patient.

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 Ari Baron's NPI number?

The NPI number for Ari Baron is 1013086420. It was assigned to this individual provider in the NPPES registry on November 7, 2006.

Where is Ari Baron located?

Ari Baron practices at 2100 Webster Street Suite 225, San Francisco, CA 94115. The listed phone number is (415) 923-3012.

What is Ari Baron's specialty?

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

Is Ari Baron enrolled in Medicare?

Yes. Ari Baron 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 Ari Baron's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Ari Baron reassigns Medicare benefits to 2 organizations: Pacific Hematology Oncology Assoc (San Francisco, CA) and Sutter Bay Medical Foundation (Orinda, 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 Ari Baron'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 Ari Baron was last updated on July 8, 2007. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 19 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.