Dr. Robert D. Siew, MD
- Medicare services, 2024
- 3,643
- Medicare patients, 2024
- 742
- Part D claims, 2024
- 2,367
- MIPS score, 2024
- 75
- Hospital affiliations
- 2
- Practice address
- 100 W. California Blvd, Pasadena, CA 91105
- Practice phone
- Call (626) 397-2618
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Huntington Hospital - Unit
Acute Care Hospital-Unit · Pasadena, California
Find Dr. Siew's professional email, personal email and mobile number
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Dr. Robert D. Siew is an internist in Pasadena, California
Dr. Siew practices at Huntington Hospital - Unit in Pasadena, California.
Dr. Siew's NPI, 1578539516, was assigned on February 28, 2006. Dr. Siew graduated from Tulane School of Medicine in 1986. Dr. Siew's California license number on file is A45333.
- NPI
- 1578539516NPI Registry (opens in a new tab)
- Medicare PAC ID
- 2769483452
- NPI enumeration date
- February 28, 2006
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (626) 397-2618
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 66
- Medical school graduation
- 1986
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Robert D. Siew practices at Huntington Hospital - Unit in Pasadena, California
Dr. Siew's primary practice is Huntington Hospital - Unit, at 100 W. California Blvd, Pasadena, CA 91105 in Los Angeles County. The practice phone is (626) 397-2618.
- Huntington Hospital - Unit100 W. California Blvd, Pasadena, CA 91105 · Los Angeles CountyPhone(626) 397-2618
Source: Dmand AI Affiliation Data
Dr. Robert D. Siew is affiliated with 5 sites of care
Dr. Siew's primary practice is Huntington Hospital - Unit in Pasadena, California. Dr. Siew is also affiliated with Huntington Hospital. Dmand AI also links Dr. Siew to 1 more physician office, 1 home health agency and 1 other site, each named with a free account.
Source: Dmand AI Affiliation Data
Dmand AI tracks the EHR system at Dr. Robert D. Siew's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Siew practices, 5 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Huntington Hospital - Unit | Available with a free account |
| +4 more affiliated sites | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Robert D. Siew is one of 16,751 internists in California
Internal medicine is Dr. Siew's primary specialty in the NPI Registry, under taxonomy code 207R00000X. Dr. Siew has a license on file in California.
Specialties and state licenses
- Internal medicine, CaliforniaPrimary
Clinical focus
Dmand AI lists acute diabetes, acute kidney failure, acute respiratory failure, acute sinusitis, acute skin infection, acute stomach ulcer, ADHD and adjustment disease among the conditions Dr. Siew treats.
Internists near Dr. Siew
Counts of internists 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. Robert D. Siew billed Medicare for 3,643 services in 2024
CMS data shows 3,643 Medicare services from Dr. Siew across 4 procedure codes in 2024, for 742 Medicare patients. Medicare paid $257,297 for them.
Dr. Siew's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Office and hospital visits
- 2023: 3,3422024: 3,6439%
Where Dr. Siew's Medicare services took place, 2024
- In an office1113%
- In a facility3,53297%
Dr. Siew compared with the California median for internists, 2024
- Dr. Siew
- California median
- Medicare services
- 3,643vs 36110.1 times
- Medicare patients
- 742vs 1514.9 times
- Part D claims
- 1,875vs 4214.5 times
Medians across 15,815 internists in California with Dmand AI profiles that report each measure.
Dr. Siew'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.
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Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Siew and other internists in California.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Robert D. Siew treated 742 Medicare patients in 2024, average age 80
CMS counts 742 Medicare patients who saw Dr. Siew in 2024. The largest group is 75 to 84, with 316 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 24% are also on Medicaid. Their average risk score is 2.06, 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. Siew's median patient age at 74, with 48% women.
Dr. Siew's Medicare patients by age, 2024
Dr. Siew's Medicare patients by sex, 2024
- Women41356%
- Men32944%
Chronic conditions among Dr. Siew's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Arthritis71%
- Diabetes51%
- Ischemic heart disease51%
- Chronic kidney disease39%
- Heart failure39%
- Mood disorders39%
Share of Medicare patients with each condition. A patient can have several.
Dr. Siew's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 74
Patient panel by sex, all payers
- Women48%
- Men51%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Robert D. Siew wrote 2,367 Medicare Part D claims in 2024
In 2024, Dr. Siew wrote 2,367 Medicare Part D claims for 471 patients. 84% of them were for generic drugs. CMS names the drug for 1,875 of them, across 53 drugs with 11 or more claims each, at $222,014 in total drug cost. In 2023, CMS named 2,104 claims across 58 drugs.
Dr. Siew's Part D claims by kind of drug, 2024
- Generic1,983 claims84%
- Brand-name and other384 claims16%
Dr. Siew'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. Siew's Part D claims, 2024
- Opioids1%24 of 2,367 claims
- Antibiotics8%192 of 2,367 claims
- Antipsychotics, patients 65 and over1%15 of 2,367 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: 2,1042024: 1,87511%
Drugs named by CMS: 53 in 2024, 58 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
Dr. Robert D. Siew scored 75 out of 100 in Medicare's MIPS program for 2024
CMS publishes a Merit-based Incentive Payment System (MIPS) score of 75 out of 100 for Dr. Siew for performance year 2024, reported individually. Dr. Siew accepts Medicare assignment, so Medicare's approved amount is taken as full payment.
- Accepts Medicare assignment
- Yes
- MIPS final score, 2024
- 75 of 100
Sources: Doctors and Clinicians National Downloadable File (CMS); and Clinician Public Reporting: Overall MIPS Performance (CMS), 2024 data, released September 10, 2026
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Dr. Robert D. Siew received $3,956 in industry payments from 2016 to 2025
CMS Open Payments shows 199 general payments to Dr. Siew from 27 drug and device companies from 2016 to 2025. Food and beverage make up the largest share, 100% of the total. GlaxoSmithKline, LLC. paid the most, $1,306.
General payments to Dr. Siew by program year, 2016 to 2025
Companies that paid Dr. Siew 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. Robert D. Siew graduated from Tulane School of Medicine
Dr. Siew graduated from Tulane School of Medicine in 1986.
- Medical school
Source: Dmand AI Professional Profile Data
Dr. Robert D. Siew accepts plans from 6 insurance carriers
Dr. Siew is in network with 6 carriers, including Blue Cross Blue Shield of Michigan, Blue Cross Blue Shield of Massachusetts and HCSC. Medicare plans come from the most carriers, 6. Check the plan with the practice before a visit.
- Blue Cross Blue Shield of Michigan
- Blue Cross Blue Shield of Massachusetts
- HCSC
- Regence Health Plans
- United Healthcare
- CMS Medicare
Plan types Dr. Siew accepts, by number of carriers
- Medicare6
- PPO5
- HMO1
- POS1
Source: Dmand AI Insurance Network Data
Sources for Dr. Robert D. Siew'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)Clinician Public Reporting: Overall MIPS Performance (CMS) (opens in a new tab) |
| 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. Robert D. Siew
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. Robert D. Siew's NPI number?
Dr. Robert D. Siew's NPI number is 1578539516. It was assigned on February 28, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Robert D. Siew?
Dr. Robert D. Siew is an internist in Pasadena, California. The primary specialty in the NPI Registry is Internal Medicine Physician (taxonomy code 207R00000X).
Where does Dr. Robert D. Siew practice?
Dr. Siew practices at 100 W. California Blvd, Pasadena, CA 91105. Dr. Siew's primary practice is Huntington Hospital - Unit in Pasadena, California. Dmand AI also links Dr. Siew to 1 physician office, 1 home health agency and 1 other site.
What is Dr. Robert D. Siew's office phone number?
The practice phone on file for Dr. Siew is (626) 397-2618.
What is Dr. Robert D. Siew's medical license number?
Dr. Siew's California license number on file is A45333.
Which hospitals is Dr. Robert D. Siew affiliated with?
Dr. Siew is affiliated with Huntington Hospital. Dmand AI links Dr. Siew to 1 more hospital.
Does Dr. Robert D. Siew accept Medicare?
Yes. CMS data shows Dr. Siew billed Medicare for 3,643 services in 2024, and Dr. Siew accepts Medicare assignment.
What is Dr. Robert D. Siew's MIPS score?
Dr. Siew's MIPS final score for performance year 2024 is 75 out of 100, reported individually.
How many Medicare patients does Dr. Robert D. Siew see?
CMS counts 742 Medicare patients who saw Dr. Siew in 2024, with an average age of 80.
What services does Dr. Robert D. Siew bill to Medicare?
In 2024, Dr. Siew's most billed Medicare services were hospital inpatient care (99232), hospital inpatient care (99238) and hospital inpatient care (99223).
Show 5 more questionsShow fewer questions
Where did Dr. Robert D. Siew go to medical school?
Dr. Siew graduated from Tulane School of Medicine in 1986.
What drugs does Dr. Robert D. Siew prescribe most?
In 2024 Medicare Part D data, Dr. Siew's most prescribed drugs by claims were Eliquis, Atorvastatin Calcium and Amlodipine Besylate.
Has Dr. Robert D. Siew received payments from drug or device companies?
CMS Open Payments shows $3,956 in general payments to Dr. Siew from 27 companies from 2016 to 2025. The largest total came from GlaxoSmithKline, LLC.
How long has Dr. Robert D. Siew been practicing?
Dr. Siew graduated from medical school in 1986, 40 years ago.
What insurance does Dr. Robert D. Siew accept?
Dr. Siew is in network with 6 carriers, including Blue Cross Blue Shield of Michigan, Blue Cross Blue Shield of Massachusetts and HCSC. Medicare plans come from the most carriers, 6. Check the plan with the practice before a visit.
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