Dr. Mark E. Williams, MD
- Medicare services, 2024
- 866
- Medicare patients, 2026
- 244
- Part D claims, 2026
- 1,285
- Hospital affiliations
- 3
- Industry payments
- $37,366
- Practice address
- 2310 Alcazar Street, Los Angeles, CA 90033
- Practice phone
- Call (323) 441-9966
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
DaVita Trc/usc Kidney Center
Dialysis Center - Independent · Los Angeles, California
Find Dr. Williams' 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. Mark E. Williams is a nephrologist in Los Angeles, California
Dr. Williams practices at DaVita Trc/usc Kidney Center in Los Angeles, California.
Dr. Williams' NPI, 1184653891, was assigned on July 3, 2006. Dr. Williams graduated from Indiana University School of Medicine in 1977. Dr. Williams holds Massachusetts license 45103.
- NPI
- 1184653891NPI Registry (opens in a new tab)
- Medicare PAC ID
- 2062443070
- NPI enumeration date
- July 3, 2006
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Offers telehealth
- Yes
- Practice phone
- (323) 441-9966
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 75
- Medical school graduation
- 1977
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Mark E. Williams practices at DaVita Trc/usc Kidney Center in Los Angeles, California
Dr. Williams' primary practice is DaVita Trc/usc Kidney Center, at 2310 Alcazar Street, Los Angeles, CA 90033 in Los Angeles County. The practice phone is (323) 441-9966.
- DaVita Trc/usc Kidney Center2310 Alcazar Street, Los Angeles, CA 90033 · Los Angeles CountyPhone(323) 441-9966
Source: Dmand AI Affiliation Data
Dr. Mark E. Williams is affiliated with 9 sites of care and 5 medical groups
Dr. Williams' primary practice is DaVita Trc/usc Kidney Center in Los Angeles, California. Dr. Williams is also affiliated with Los Angeles General Medical Center. The medical group on file is USC Care Medical Group. Dmand AI also links Dr. Williams to 2 more hospitals, 4 group practices and clinics, 4 medical groups and 1 other site, each named with a free account.
Sources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Mark E. Williams' practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Williams practices, 9 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| DaVita Trc/usc Kidney Center | Available with a free account |
| +8 more sites and 4 medical groups | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Mark E. Williams is one of 1,401 nephrologists in California
Nephrology is Dr. Williams' primary specialty in the NPI Registry, under taxonomy code 207RN0300X. Dr. Williams is licensed in Massachusetts.
Specialties and state licenses
- Nephrology, MassachusettsPrimary
Nephrologists near Dr. Williams
Counts of nephrologists 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. Mark E. Williams billed Medicare for 866 services in 2024
CMS data shows 866 Medicare services from Dr. Williams across 10 procedure codes in 2024, for 244 Medicare patients. Medicare paid $91,649 for them.
Dr. Williams' Medicare services by type, 2023 to 2024
- 2023
- 2024
- Tests and treatments
- 2023: 3722024: 44520%
- Office and hospital visits
- 2023: 3512024: 351No change
- Other services
- 2023: 02024: 70
Where Dr. Williams' Medicare services took place, 2024
- In an office11814%
- In a facility74886%
Dr. Williams compared with the California median for nephrologists, 2024
- Dr. Williams
- California median
- Medicare services
- 866vs 1,08420% below
- Medicare patients
- 244vs 30721% below
- Part D claims
- 1,120vs 95517% above
Medians across 1,355 nephrologists in California with Dmand AI profiles that report each measure.
Dr. Williams' 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. Williams?
Medicare shows one payer. Book a meeting to get commercial claims data for Dr. Williams and other nephrologists in California.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Mark E. Williams treated 244 Medicare patients in 2026, average age 71
CMS counts 244 Medicare patients who saw Dr. Williams in 2026. The largest group is 65 to 74, with 89 patients. 75% of them have chronic kidney disease, and 75% have diabetes. 41% are also on Medicaid. Their average risk score is 6.23, 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. Williams' median patient age at 65, with 37% women.
Dr. Williams' Medicare patients by age, 2026
Dr. Williams' Medicare patients by sex, 2026
- Women9639%
- Men14861%
Chronic conditions among Dr. Williams' Medicare patients, 2026
- Chronic kidney disease75%
- Diabetes75%
- High blood pressure75%
- High cholesterol75%
- Ischemic heart disease62%
- Heart failure56%
- Arthritis44%
- Mood disorders39%
Share of Medicare patients with each condition. A patient can have several.
Dr. Williams' patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 65
Patient panel by sex, all payers
- Women37%
- Men62%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2026 data
Dr. Mark E. Williams wrote 1,285 Medicare Part D claims in 2026
In 2026, Dr. Williams wrote 1,285 Medicare Part D claims for 172 patients. 77% of them were for generic drugs. CMS names the drug for 1,120 of them, across 27 drugs with 11 or more claims each, at $316,958 in total drug cost. In 2023, CMS named 1,129 claims across 30 drugs.
Dr. Williams' Part D claims by kind of drug, 2026
- Generic995 claims77%
- Brand-name and other290 claims23%
Dr. Williams' 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.
Part D claims for drugs CMS names, 2023 to 2024
- 2023
- 2024
- Claims for drugs CMS names
- 2023: 1,1292024: 1,1201%
Drugs named by CMS: 27 in 2024, 30 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), 2026 data
Dr. Mark E. Williams offers telehealth to Medicare patients
Dr. Williams accepts Medicare assignment, so Medicare's approved amount is taken as full payment. CMS lists Dr. Williams as offering telehealth.
- Accepts Medicare assignment
- Yes
- Offers telehealth
- Yes
Source: Doctors and Clinicians National Downloadable File (CMS)
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Dr. Mark E. Williams received $37,366 in industry payments from 2016 to 2025
CMS Open Payments shows 73 general payments to Dr. Williams from 12 drug and device companies from 2016 to 2025. Consulting fees make up the largest share, 61% of the total. Novo Nordisk Inc paid the most, $23,137. It also lists 2 research payments totaling $486 from 2016 to 2019.
General payments to Dr. Williams by program year, 2016 to 2025
General payments to Dr. Williams by kind, 2016 to 2025
- Consulting fees$22,96261%
- Education speaker fees$6,50017%
- Travel and lodging$4,47212%
- Food and beverage$3,3479%
- Other$850%
Companies that paid Dr. Williams 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. Mark E. Williams graduated from Indiana University School of Medicine
Dr. Williams graduated from Indiana University School of Medicine in 1977.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Mark E. Williams'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 DataDmand AI Org Hierarchy 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) |
| Industry payments | Open Payments (CMS) (opens in a new tab) |
| Training, board certification and memberships | Dmand AI Professional Profile 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. Mark E. Williams
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. Mark E. Williams' NPI number?
Dr. Mark E. Williams' NPI number is 1184653891. It was assigned on July 3, 2006, and it is active in the NPI Registry.
What kind of doctor is Dr. Mark E. Williams?
Dr. Mark E. Williams is a nephrologist in Los Angeles, California. The primary specialty in the NPI Registry is Nephrology Physician (taxonomy code 207RN0300X).
Where does Dr. Mark E. Williams practice?
Dr. Williams practices at 2310 Alcazar Street, Los Angeles, CA 90033. Dr. Williams' primary practice is DaVita Trc/usc Kidney Center in Los Angeles, California. Dmand AI also links Dr. Williams to 2 hospitals, 4 group practices and clinics, 4 medical groups and 1 other site, and a free account names each one.
What is Dr. Mark E. Williams' office phone number?
The practice phone on file for Dr. Williams is (323) 441-9966. Dmand AI also checks direct phone and mobile numbers, available with a free account.
What is Dr. Mark E. Williams' email address?
Dmand AI checks professional and personal email addresses for Dr. Williams through healthcare-specific waterfall enrichment. They are available with a free Dmand AI account.
What is Dr. Mark E. Williams' medical license number?
Dr. Williams holds Massachusetts license 45103.
Which hospitals is Dr. Mark E. Williams affiliated with?
Dr. Williams is affiliated with Los Angeles General Medical Center. Dmand AI links Dr. Williams to 2 more hospitals, named with a free account.
What medical group is Dr. Mark E. Williams part of?
Dr. Williams is linked to USC Care Medical Group. Dmand AI links Dr. Williams to 4 more medical groups, named with a free account.
Who does Dr. Mark E. Williams practice with?
Dmand AI links 1,886 HCPs to Dr. Williams' primary medical group, 21 of them nephrologists. A free account lists them, with verified contacts.
Does Dr. Mark E. Williams accept Medicare?
Yes. CMS data shows Dr. Williams billed Medicare for 866 services in 2024, and Dr. Williams accepts Medicare assignment.
Show 8 more questionsShow fewer questions
Does Dr. Mark E. Williams offer telehealth?
Yes. The CMS Doctors and Clinicians file lists Dr. Williams as offering telehealth services.
How many Medicare patients does Dr. Mark E. Williams see?
CMS counts 244 Medicare patients who saw Dr. Williams in 2026, with an average age of 71.
What services does Dr. Mark E. Williams bill to Medicare?
In 2024, Dr. Williams' most billed Medicare services were dialysis (90935), office visit, established patient (99215) and hospital inpatient care (99233).
Where did Dr. Mark E. Williams go to medical school?
Dr. Williams graduated from Indiana University School of Medicine in 1977.
What drugs does Dr. Mark E. Williams prescribe most?
In 2024 Medicare Part D data, Dr. Williams' most prescribed drugs by claims were Calcitriol, Irbesartan and Amlodipine Besylate.
Has Dr. Mark E. Williams received payments from drug or device companies?
CMS Open Payments shows $37,366 in general payments to Dr. Williams from 12 companies from 2016 to 2025. The largest total came from Novo Nordisk Inc.
How long has Dr. Mark E. Williams been practicing?
Dr. Williams graduated from medical school in 1977, 49 years ago.
What EHR does Dr. Mark E. Williams' practice use?
Dmand AI tracks the EHR system at DaVita Trc/usc Kidney Center and at 8 more sites and 4 medical groups. The vendor and product are available with a free Dmand AI account.
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