Dr. John P. Williams, DO
- Medicare services, 2024
- 1,874
- Medicare patients, 2024
- 317
- Part D claims, 2024
- 11,847
- MIPS score, 2024
- 37
- Hospital affiliations
- 4
- Practice address
- 1 Marcela Dr, Willits, CA 95490
- Practice phone
- Call (707) 456-3031
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
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Dr. John P. Williams is an internist in Willits, California
Dr. Williams practices at Adventist Health Howard Memorial in Willits, California, part of Adventist Health.
Dr. Williams' NPI, 1144220369, was assigned on July 29, 2005. Dr. Williams graduated from University of New England, College of Osteo Medicine in 1989. Dr. Williams holds California license 20A6027.
- NPI
- 1144220369NPI Registry (opens in a new tab)
- Medicare PAC ID
- 0941237382
- NPI enumeration date
- July 29, 2005
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (707) 456-3031
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 63
- Medical school graduation
- 1989
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. John P. Williams practices at Adventist Health Howard Memorial in Willits, California
Dr. Williams' primary practice is Adventist Health Howard Memorial, at 1 Marcela Dr, Willits, CA 95490 in Mendocino County. The practice phone is (707) 456-3031.
- Adventist Health Howard Memorial1 Marcela Dr, Willits, CA 95490 · Mendocino CountyPhone(707) 456-3031
Source: Dmand AI Affiliation Data
Dr. John P. Williams is affiliated with 6 sites of care
Dr. Williams' primary practice is Adventist Health Howard Memorial in Willits, California, part of Adventist Health. Dr. Williams is also affiliated with Adventist Health Ukiah Valley. Dmand AI also links Dr. Williams to 2 more hospitals and 2 home health agencies, 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. John P. Williams' practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Williams practices, 6 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Adventist Health Howard Memorial | Available with a free account |
| +5 more affiliated sites | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. John P. Williams is one of 16,751 internists in California
Internal medicine is Dr. Williams' primary specialty in the NPI Registry, under taxonomy code 207R00000X. Dr. Williams is licensed in California.
Specialties and state licenses
- Internal medicine, CaliforniaPrimary
Internists near Dr. Williams
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. John P. Williams billed Medicare for 1,874 services in 2024
CMS data shows 1,874 Medicare services from Dr. Williams across 13 procedure codes in 2024, for 317 Medicare patients. Medicare paid $126,319 for them.
Dr. Williams' Medicare services by type, 2023 to 2024
- 2023
- 2024
- Office and hospital visits
- 2023: 1,9102024: 1,37228%
- Lab and pathology
- 2023: 5432024: 41923%
- Tests and treatments
- 2023: 812024: 4742%
- Other services
- 2023: 202024: 1810%
- Surgery
- 2023: 382024: 1853%
Where Dr. Williams' Medicare services took place, 2024
- In an office1,82397%
- In a facility513%
Dr. Williams compared with the California median for internists, 2024
- Dr. Williams
- California median
- Medicare services
- 1,874vs 3615.2 times
- Medicare patients
- 317vs 1512.1 times
- Part D claims
- 11,077vs 42126.3 times
Medians across 15,815 internists 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.
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Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. John P. Williams treated 317 Medicare patients in 2024, average age 74
CMS counts 317 Medicare patients who saw Dr. Williams in 2024. The largest group is 65 to 74, with 145 patients. 75% of them have high blood pressure, and 55% have arthritis. 44% are also on Medicaid. Their average risk score is 1.61, 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 69, with 50% women.
Dr. Williams' Medicare patients by age, 2024
Dr. Williams' Medicare patients by sex, 2024
- Women17555%
- Men14245%
Chronic conditions among Dr. Williams' Medicare patients, 2024
- High blood pressure75%
- Arthritis55%
- Diabetes54%
- High cholesterol40%
- Alcohol and drug use disorders36%
- Chronic kidney disease27%
- Mood disorders26%
- Depression25%
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 69
Patient panel by sex, all payers
- Women50%
- Men50%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. John P. Williams wrote 11,847 Medicare Part D claims in 2024
In 2024, Dr. Williams wrote 11,847 Medicare Part D claims for 389 patients. 87% of them were for generic drugs. CMS names the drug for 11,077 of them, across 176 drugs with 11 or more claims each, at $790,592 in total drug cost. In 2023, CMS named 14,584 claims across 200 drugs.
Dr. Williams' Part D claims by kind of drug, 2024
- Generic10,283 claims87%
- Brand-name1,521 claims13%
- Other43 claims0%
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.
Drug classes CMS tracks in Dr. Williams' Part D claims, 2024
- Opioids9%1,060 of 11,847 claims
- Antibiotics2%292 of 11,847 claims
- Antipsychotics, patients 65 and over2%252 of 11,847 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: 14,5842024: 11,07724%
Drugs named by CMS: 176 in 2024, 200 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. John P. Williams scored 37 out of 100 in Medicare's MIPS program for 2024
CMS publishes a Merit-based Incentive Payment System (MIPS) score of 37 out of 100 for Dr. Williams for performance year 2024, reported individually. Dr. Williams accepts Medicare assignment, so Medicare's approved amount is taken as full payment. CMS counts 38 procedures of removal of skin lesions by Dr. Williams, more than 70% of the clinicians it reports for that procedure.
- Accepts Medicare assignment
- Yes
Dr. Williams' MIPS scores, performance year 2024
- 37of 100Final score
- 15of 100Quality
- 0of 100Improvement Activities
- 76of 100Cost
Each score is out of 100. The final score weighs the categories CMS scored for this clinician.
Where Dr. Williams ranks in Medicare procedure volume
- Removal of skin lesions
- 70th percentile38 procedures
CMS ranks each clinician against every clinician it reports for the same procedure category.
Melanoma (skin cancer) excision: 1 to 10 procedures (CMS shows small counts as a range)
Skin biopsy: 1 to 10 procedures (CMS shows small counts as a range)
Sources: Doctors and Clinicians National Downloadable File (CMS); Clinician Public Reporting: Overall MIPS Performance (CMS), 2024 data, released September 10, 2026; and Doctors and Clinicians Utilization Data (CMS)
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Dr. John P. Williams received $8,406 in industry payments from 2016 to 2025
CMS Open Payments shows 519 general payments to Dr. Williams from 31 drug and device companies from 2016 to 2025. Food and beverage make up the largest share, 98% of the total. Novo Nordisk Inc paid the most, $2,204.
General payments to Dr. Williams by program year, 2016 to 2025
General payments to Dr. Williams by kind, 2016 to 2025
- Food and beverage$8,21398%
- Education$1942%
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. John P. Williams graduated from University of New England, College of Osteo Medicine
Dr. Williams graduated from University of New England, College of Osteo Medicine in 1989.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. John P. 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)Clinician Public Reporting: Overall MIPS Performance (CMS) (opens in a new tab)Doctors and Clinicians Utilization Data (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. John P. 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. John P. Williams' NPI number?
Dr. John P. Williams' NPI number is 1144220369. It was assigned on July 29, 2005, and it is active in the NPI Registry.
What kind of doctor is Dr. John P. Williams?
Dr. John P. Williams is an internist in Willits, California. The primary specialty in the NPI Registry is Internal Medicine Physician (taxonomy code 207R00000X).
Where does Dr. John P. Williams practice?
Dr. Williams practices at 1 Marcela Dr, Willits, CA 95490. Dr. Williams' primary practice is Adventist Health Howard Memorial in Willits, California, part of Adventist Health. Dmand AI also links Dr. Williams to 2 hospitals and 2 home health agencies.
What is Dr. John P. Williams' office phone number?
The practice phone on file for Dr. Williams is (707) 456-3031.
What is Dr. John P. Williams' medical license number?
Dr. Williams holds California license 20A6027.
Which hospitals is Dr. John P. Williams affiliated with?
Dr. Williams practices at Adventist Health Howard Memorial in Willits, California. Dr. Williams is also affiliated with Adventist Health Ukiah Valley. Dmand AI links Dr. Williams to 2 more hospitals.
Does Dr. John P. Williams accept Medicare?
Yes. CMS data shows Dr. Williams billed Medicare for 1,874 services in 2024, and Dr. Williams accepts Medicare assignment.
What is Dr. John P. Williams' MIPS score?
Dr. Williams' MIPS final score for performance year 2024 is 37 out of 100, reported individually.
How many Medicare patients does Dr. John P. Williams see?
CMS counts 317 Medicare patients who saw Dr. Williams in 2024, with an average age of 74.
What services does Dr. John P. Williams bill to Medicare?
In 2024, Dr. Williams' most billed Medicare services were office visit, established patient (99214), lab and pathology test (80305) and office visit, established patient (99215).
Show 4 more questionsShow fewer questions
Where did Dr. John P. Williams go to medical school?
Dr. Williams graduated from University of New England, College of Osteo Medicine in 1989.
What drugs does Dr. John P. Williams prescribe most?
In 2024 Medicare Part D data, Dr. Williams' most prescribed drugs by claims were Atorvastatin Calcium, Amlodipine Besylate and Gabapentin.
Has Dr. John P. Williams received payments from drug or device companies?
CMS Open Payments shows $8,406 in general payments to Dr. Williams from 31 companies from 2016 to 2025. The largest total came from Novo Nordisk Inc.
How long has Dr. John P. Williams been practicing?
Dr. Williams graduated from medical school in 1989, 37 years ago.
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