Dr. Alex Diaz, DO
- Medicare services, 2024
- 2,014
- Medicare patients, 2024
- 414
- Part D claims, 2024
- 1,257
- Publications
- 1
- Hospital affiliations
- 4
- Practice address
- 5401 Norris Canyon Rd Ste 308, San Ramon, CA 94583-5408
- Practice phone
- Call (925) 866-8822
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Tassajara Critical Care
Physician office · San Ramon, California
Find Dr. Diaz's professional email, personal email and mobile number
Dmand AI checks each channel through healthcare-specific waterfall enrichment. See what is on file with a free account, with practice phones, licenses and affiliations.
Dr. Alex Diaz is a pulmonologist in San Ramon, California
Dr. Diaz practices at Tassajara Critical Care in San Ramon, California.
Dr. Diaz's NPI, 1659759363, was assigned on May 13, 2015. Dr. Diaz graduated from WesternU College of Osteopathic Medicine of the Pacific in 2015. Dr. Diaz holds California license 20A18649.
- NPI
- 1659759363NPI Registry (opens in a new tab)
- Medicare PAC ID
- 6608292313
- NPI enumeration date
- May 13, 2015
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (925) 866-8822
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 37
- Medical school graduation
- 2015
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Alex Diaz practices at Tassajara Critical Care in San Ramon, California
Dr. Diaz's primary practice is Tassajara Critical Care, at 5401 Norris Canyon Rd Ste 308, San Ramon, CA 94583-5408. The practice phone is (925) 866-8822.
- Tassajara Critical Care5401 Norris Canyon Rd Ste 308, San Ramon, CA 94583-5408Phone(925) 866-8822
Source: Dmand AI Affiliation Data
Dr. Alex Diaz is affiliated with 7 sites of care and 1 medical group
Dr. Diaz's primary practice is Tassajara Critical Care in San Ramon, California. Dr. Diaz is also affiliated with San Ramon Regional Medical Center. The medical group on file is Nassau University Medical Center (NUMC), Department of Psychiatry and Behavioral Sciences. Dmand AI also links Dr. Diaz to 3 more hospitals and 2 home health agencies, each named with a free account.
Source: Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Dr. Alex Diaz's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Diaz practices, 7 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Tassajara Critical Care | Available with a free account |
| +6 more affiliated sites | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Alex Diaz is one of 1,339 pulmonologists in California
Pulmonary disease is Dr. Diaz's primary specialty in the NPI Registry, under taxonomy code 207RP1001X. Dr. Diaz is board certified in critical care medicine by the American Board of Internal Medicine. Dr. Diaz is licensed in California.
Specialties and state licenses
- Pulmonary disease, CaliforniaPrimary
Clinical focus
Dmand AI lists acute respiratory failure, asthma, chronic diabetes, chronic hypertension, chronic lung disease, chronic obstructive pulmonary disease (COPD), collapsed lung and congestive heart failure among the conditions Dr. Diaz treats.
Pulmonologists near Dr. Diaz
Counts of pulmonologists with a Dmand AI profile, by place and practice. Each opens the list.
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Dr. Alex Diaz billed Medicare for 2,014 services in 2024
CMS data shows 2,014 Medicare services from Dr. Diaz across 12 procedure codes in 2024, for 414 Medicare patients. Medicare paid $177,209 for them.
Dr. Diaz's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Office and hospital visits
- 2023: 1,3762024: 1,86135%
- Tests and treatments
- 2023: 1292024: 15319%
- Surgery
- 2023: 342024: 0100%
Where Dr. Diaz's Medicare services took place, 2024
- In an office40920%
- In a facility1,60580%
Dr. Diaz compared with the California median for pulmonologists, 2024
- Dr. Diaz
- California median
- Medicare services
- 2,014vs 6493.1 times
- Medicare patients
- 414vs 27252% above
- Part D claims
- 860vs 4212.0 times
Medians across 1,263 pulmonologists in California with Dmand AI profiles that report each measure.
Dr. Diaz's most billed Medicare procedure codes, 2024
CMS publishes codes billed for 11 or more Medicare patients. Each label is the code family; CPT descriptions are licensed by the AMA.
Need commercial claims for Dr. Diaz?
Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Diaz and other pulmonologists in California.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Alex Diaz treated 414 Medicare patients in 2024, average age 76
CMS counts 414 Medicare patients who saw Dr. Diaz in 2024. The largest group is 75 to 84, with 172 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 29% are also on Medicaid. Their average risk score is 1.92, where 1.00 is the Medicare average, so they are sicker than most Medicare patients.
Across all payers, Dmand AI patient panel data puts Dr. Diaz's median patient age at 72, with 52% women.
Dr. Diaz's Medicare patients by age, 2024
Dr. Diaz's Medicare patients by sex, 2024
- Women23657%
- Men17843%
Chronic conditions among Dr. Diaz's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Arthritis58%
- Diabetes40%
- Chronic kidney disease38%
- COPD36%
- Ischemic heart disease35%
- Atrial fibrillation32%
Share of Medicare patients with each condition. A patient can have several.
Dr. Diaz's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 72
Patient panel by sex, all payers
- Women52%
- Men47%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Alex Diaz wrote 1,257 Medicare Part D claims in 2024
In 2024, Dr. Diaz wrote 1,257 Medicare Part D claims for 210 patients. 67% of them were for generic drugs. CMS names the drug for 860 of them, across 32 drugs with 11 or more claims each, at $229,894 in total drug cost. In 2023, CMS named 528 claims across 23 drugs.
Dr. Diaz's Part D claims by kind of drug, 2024
- Generic839 claims67%
- Brand-name and other418 claims33%
Dr. Diaz's most prescribed drugs by claims, 2024
CMS names a drug when it has 11 or more claims. Share is of the claims for drugs CMS names.
Drug classes CMS tracks in Dr. Diaz's Part D claims, 2024
- Opioids2%23 of 1,257 claims
- Antibiotics6%76 of 1,257 claims
Share of all Part D claims for each drug class CMS reports on. Classes with no claims are left out.
Part D claims for drugs CMS names, 2023 to 2024
- 2023
- 2024
- Claims for drugs CMS names
- 2023: 5282024: 86063%
Drugs named by CMS: 32 in 2024, 23 in 2023.
Sources: Medicare Part D Prescribers - by Provider and Drug (CMS), 2024 data, released May 6, 2026; and Medicare Part D Prescribers - by Provider (CMS), 2024 data
How Dr. Alex Diaz takes part in Medicare
Dr. Diaz accepts Medicare assignment, so Medicare's approved amount is taken as full payment.
- Accepts Medicare assignment
- Yes
Source: Doctors and Clinicians National Downloadable File (CMS)
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Dr. Alex Diaz has 1 publication on record
Dmand AI links 1 paper to Dr. Diaz in 2017.
Recent publications by Dr. Diaz
See who Dr. Diaz researches with
Physician Network Discovery turns co-authorship, shared hospitals and shared groups into a map of who Dr. Diaz works with, so you can find a warm path to the right pulmonologists.
Sources: PubMed (National Library of Medicine); and Dmand AI Research Linkage
Dr. Alex Diaz received $4,926 in industry payments from 2016 to 2025
CMS Open Payments shows 218 general payments to Dr. Diaz from 38 drug and device companies from 2016 to 2025. Food and beverage make up the largest share, 95% of the total. GlaxoSmithKline, LLC. paid the most, $961.
General payments to Dr. Diaz by program year, 2016 to 2025
General payments to Dr. Diaz by kind, 2016 to 2025
- Food and beverage$4,68895%
- Education$2385%
Companies that paid Dr. Diaz the most, 2016 to 2025
Share is of all general payments to this clinician.
Source: Open Payments (CMS), 2025 data, released July 7, 2026
Dr. Alex Diaz graduated from WesternU College of Osteopathic Medicine of the Pacific
Dr. Diaz graduated from WesternU College of Osteopathic Medicine of the Pacific in 2015. Dr. Diaz is a member of ACCP, SCCM, ACOI, ACP and ATS.
- Medical school
- Board certified in critical care medicine
- Board certified in internal medicine
- Board certified in pulmonary disease
- Board certified in 2021 - 2026
- Board certified in 2016 - 2027
- Board certified in 2018 - 2025
Source: Dmand AI Professional Profile Data
Dr. Alex Diaz accepts plans from 15 insurance carriers
Dr. Diaz is in network with 15 carriers, including Aetna, Blue Cross Blue Shield of Michigan and Elevance. Medicare plans come from the most carriers, 9. Check the plan with the practice before a visit.
- Aetna
- Blue Cross Blue Shield of Michigan
- Elevance
- United Healthcare
- HCSC
- Blue Cross Blue Shield of Massachusetts
- Humana
- Regence Health Plans
- +7 more carriersWith a free account
Plan types Dr. Diaz accepts, by number of carriers
- Medicare9
- PPO9
- HMO6
- POS5
- EPO4
Source: Dmand AI Insurance Network Data
Sources for Dr. Alex Diaz's profile data
| Data on this page | Source |
|---|---|
| NPI, name, sex, specialty and licenses | NPPES NPI Registry (CMS) (opens in a new tab)Dmand AI Professional Profile Data |
| Practice locations and phone | Dmand AI Affiliation Data |
| Primary practice, affiliations and health system | Dmand AI Affiliation Data |
| Medicare services and procedure codes | Medicare Physician & Other Practitioners - by Provider and Service (CMS) (opens in a new tab) |
| State medians for the same specialty | Dmand AI Peer Benchmarks |
| Medicare patients and the all-payer patient panel | Dmand AI Patient Panel DataMedicare Physician & Other Practitioners - by Provider (CMS) (opens in a new tab) |
| Part D prescribing | Medicare Part D Prescribers - by Provider and Drug (CMS) (opens in a new tab)Medicare Part D Prescribers - by Provider (CMS) (opens in a new tab) |
| MIPS scores, telehealth, assignment and procedure percentiles | Doctors and Clinicians National Downloadable File (CMS) (opens in a new tab) |
| Publications, topics and co-authors | PubMed (National Library of Medicine) (opens in a new tab)Dmand AI Research Linkage |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| Training, board certification and memberships | Dmand AI Professional Profile Data |
| Insurance carriers and plan types | Dmand AI Insurance Network Data |
| EHR at each practice site | Dmand AI Technology Install Data |
| Similar physicians | Dmand AI Affiliation Data |
Data last refreshed October 2026Report an inaccuracyRemove my information
FAQ
Frequently asked questions about Dr. Alex Diaz
Spotted something out of date? Email hello@dmand.ai and we will check the record. Contact details live in the free trial.
What is Dr. Alex Diaz's NPI number?
Dr. Alex Diaz's NPI number is 1659759363. It was assigned on May 13, 2015, and it is active in the NPI Registry.
What kind of doctor is Dr. Alex Diaz?
Dr. Alex Diaz is a pulmonologist in San Ramon, California. The primary specialty in the NPI Registry is Pulmonary Disease Physician (taxonomy code 207RP1001X).
Where does Dr. Alex Diaz practice?
Dr. Diaz practices at 5401 Norris Canyon Rd Ste 308, San Ramon, CA 94583-5408. Dr. Diaz's primary practice is Tassajara Critical Care in San Ramon, California. Dmand AI also links Dr. Diaz to 3 hospitals and 2 home health agencies.
What is Dr. Alex Diaz's office phone number?
The practice phone on file for Dr. Diaz is (925) 866-8822.
What is Dr. Alex Diaz's medical license number?
Dr. Diaz holds California license 20A18649.
Which hospitals is Dr. Alex Diaz affiliated with?
Dr. Diaz is affiliated with San Ramon Regional Medical Center. Dmand AI links Dr. Diaz to 3 more hospitals.
What medical group is Dr. Alex Diaz part of?
Dr. Diaz is linked to Nassau University Medical Center (NUMC), Department of Psychiatry and Behavioral Sciences.
Does Dr. Alex Diaz accept Medicare?
Yes. CMS data shows Dr. Diaz billed Medicare for 2,014 services in 2024, and Dr. Diaz accepts Medicare assignment.
How many Medicare patients does Dr. Alex Diaz see?
CMS counts 414 Medicare patients who saw Dr. Diaz in 2024, with an average age of 76.
Is Dr. Alex Diaz board certified?
Yes. Dr. Diaz is board certified in critical care medicine by the American Board of Internal Medicine.
Show 7 more questionsShow fewer questions
What services does Dr. Alex Diaz bill to Medicare?
In 2024, Dr. Diaz's most billed Medicare services were nursing facility care (99308), hospital inpatient care (99232) and hospital inpatient care (99233).
Where did Dr. Alex Diaz go to medical school?
Dr. Diaz graduated from WesternU College of Osteopathic Medicine of the Pacific in 2015.
What drugs does Dr. Alex Diaz prescribe most?
In 2024 Medicare Part D data, Dr. Diaz's most prescribed drugs by claims were Trelegy Ellipta, Montelukast Sodium and Albuterol Sulfate Hfa.
Has Dr. Alex Diaz received payments from drug or device companies?
CMS Open Payments shows $4,926 in general payments to Dr. Diaz from 38 companies from 2016 to 2025. The largest total came from GlaxoSmithKline, LLC.
How long has Dr. Alex Diaz been practicing?
Dr. Diaz graduated from medical school in 2015, 11 years ago.
Does Dr. Alex Diaz do research?
Dmand AI links 1 publication to Dr. Diaz.
What insurance does Dr. Alex Diaz accept?
Dr. Diaz is in network with 15 carriers, including Aetna, Blue Cross Blue Shield of Michigan and Elevance. Medicare plans come from the most carriers, 9. Check the plan with the practice before a visit.
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