Diagn Microbiol Infect Dis
Anti-Bacterial AgentsDrug Resistance, BacterialMicrobial Sensitivity Tests
Dr. Hollis W. Walker, MD
NPI1053622290PAC ID2365745155
- Medicare services, 2024
- 1,078
- Medicare patients, 2024
- 308
- Part D claims, 2024
- 394
- Publications
- 12
- MIPS score, 2024
- 85
- Practice address
- 2650 Ridge Ave, Evanston, IL 60201
- Practice phone
- Call (847) 570-2000
- Professional email
- Get professional email
- Personal email
- Get personal email
- Mobile number
- Get mobile number
Primary practice
Find Dr. Walker'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. Hollis W. Walker is a hematologist and oncologist in Evanston, Illinois
Dr. Walker practices at Evanston Hospital in Evanston, Illinois, part of Endeavor Health.
Dr. Walker's NPI, 1053622290, was assigned on June 22, 2010. Dr. Walker graduated from Clvlnd Clinic Lerner College of Med of Case Wstn Rsv University in 2010. Dr. Walker holds Illinois license 036.141268.
NPI and contact details
- NPI
- 1053622290NPI Registry (opens in a new tab)
- Medicare PAC ID
- 2365745155
- NPI enumeration date
- June 22, 2010
- NPI status
- Active
- Accepts Medicare assignment
- Yes
- Practice phone
- (847) 570-2000
- Professional email
- Get email
- Personal email
- Get email
- Mobile number
- Get number
- Sex
- Male
- Estimated age
- 42
- Medical school graduation
- 2010
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; Dmand AI Affiliation Data; and Doctors and Clinicians National Downloadable File (CMS)
Dr. Hollis W. Walker practices at Evanston Hospital in Evanston, Illinois
Dr. Walker's primary practice is Evanston Hospital, at 2650 Ridge Ave, Evanston, IL 60201 in Cook County. The practice phone is (847) 570-2000.
- Evanston Hospital2650 Ridge Ave, Evanston, IL 60201 · Cook CountyPhone(847) 570-2000
Source: Dmand AI Affiliation Data
Dr. Hollis W. Walker is affiliated with 6 sites of care and 2 medical groups
Dr. Walker's primary practice is Evanston Hospital in Evanston, Illinois, part of Endeavor Health. Dr. Walker is also affiliated with Swedish Hospital. The medical group on file is Endeavor Health Medical Group. Dmand AI also links Dr. Walker to 2 more hospitals, 2 group practices and clinics and 1 medical group, each named with a free account.
Swedish HospitalEndeavor Health Medical Group2 hospitalsNames with a free account2 group practices and clinicsNames with a free account1 medical groupName with a free account
See all 8 affiliations for Dr. WalkerSources: Dmand AI Affiliation Data; and Dmand AI Org Hierarchy Data
Dmand AI tracks the EHR system at Dr. Hollis W. Walker's practice
Dmand AI tracks the electronic health record (EHR) system at each site where Dr. Walker practices, 6 sites in all. Vendor and product names are available with a free account.
| Site | EHR vendor and product |
|---|---|
| Evanston Hospital | Available with a free account |
| +5 more sites and 1 medical group | Available with a free account |
Source: Dmand AI Technology Install Data
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Dr. Hollis W. Walker is one of 563 hematologists and oncologists in Illinois
Hematology and oncology is Dr. Walker's primary specialty in the NPI Registry, under taxonomy code 207RH0003X. Dr. Walker is licensed in Illinois.
Specialties and state licenses
- Hematology and oncology, IllinoisPrimary
Hematologists and oncologists near Dr. Walker
Counts of hematologists and oncologists with a Dmand AI profile, by place and practice. Each opens the list.
563hematologists and oncologists in Illinois26hematologists and oncologists in Evanston22hematologists and oncologists at Evanston Hospital
Sources: NPPES NPI Registry (CMS); Dmand AI Professional Profile Data; and Dmand AI Peer Benchmarks
Dr. Hollis W. Walker billed Medicare for 1,078 services in 2024
CMS data shows 1,078 Medicare services from Dr. Walker across 10 procedure codes in 2024, for 308 Medicare patients. Medicare paid $92,210 for them.
Medicare services, 20241,078
Medicare patients308
Paid by Medicare$92,210
Procedure codes10
Dr. Walker's Medicare services by type, 2023 to 2024
- 2023
- 2024
- Office and hospital visits
- 2023: 9942024: 89410%
- Other services
- 2023: 02024: 184
Where Dr. Walker's Medicare services took place, 2024
- In an office454%
- In a facility1,03396%
Dr. Walker compared with the Illinois median for hematologists and oncologists, 2024
- Dr. Walker
- Illinois median
- Medicare services
- 1,078vs 1,056Close to median
- Medicare patients
- 308vs 2829% above
- Part D claims
- 268vs 32818% below
Medians across 547 hematologists and oncologists in Illinois with Dmand AI profiles that report each measure.
Dr. Walker'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. Walker and other hematologists and oncologists in Illinois.
Sources: Medicare Physician & Other Practitioners - by Provider and Service (CMS), 2024 data; and Dmand AI Peer Benchmarks
Dr. Hollis W. Walker treated 308 Medicare patients in 2024, average age 76
CMS counts 308 Medicare patients who saw Dr. Walker in 2024. The largest group is 75 to 84, with 123 patients. 75% of them have high blood pressure, and 75% have high cholesterol. 13% are also on Medicaid. Their average risk score is 2.13, 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. Walker's median patient age at 66, with 55% women.
Medicare patients, 2024308
Average age76
Average risk score2.13
Also on Medicaid13%
Dr. Walker's Medicare patients by age, 2024
Dr. Walker's Medicare patients by sex, 2024
- Women16253%
- Men14647%
Chronic conditions among Dr. Walker's Medicare patients, 2024
- High blood pressure75%
- High cholesterol75%
- Arthritis51%
- Ischemic heart disease42%
- Cancer40%
- Chronic kidney disease37%
- Diabetes35%
- COPD29%
Share of Medicare patients with each condition. A patient can have several.
Dr. Walker's patients across all payers
Dmand AI patient panel data covers Medicare, Medicaid and commercial patients.
Patient panel by age, all payers
Median age 66
Patient panel by sex, all payers
- Women55%
- Men45%
Sources: Dmand AI Patient Panel Data; and Medicare Physician & Other Practitioners - by Provider (CMS), 2024 data
Dr. Hollis W. Walker wrote 394 Medicare Part D claims in 2024
In 2024, Dr. Walker wrote 394 Medicare Part D claims for 103 patients. 52% of them were for generic drugs. CMS names the drug for 268 of them, across 10 drugs with 11 or more claims each, at $1,327,754 in total drug cost. In 2023, CMS named 282 claims across 13 drugs.
Part D claims, 2024394
Drugs named by CMS10
Total drug cost$1.3M
Part D patients103
Dr. Walker's Part D claims by kind of drug, 2024
- Generic204 claims52%
- Brand-name190 claims48%
Dr. Walker'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.
Part D claims for drugs CMS names, 2023 to 2024
- 2023
- 2024
- Claims for drugs CMS names
- 2023: 2822024: 2685%
Drugs named by CMS: 10 in 2024, 13 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. Hollis W. Walker scored 85 out of 100 in Medicare's MIPS program for 2024
CMS publishes a Merit-based Incentive Payment System (MIPS) score of 85 out of 100 for Dr. Walker for performance year 2024, reported as part of a group. Dr. Walker accepts Medicare assignment, so Medicare's approved amount is taken as full payment.
- Accepts Medicare assignment
- Yes
Dr. Walker's MIPS scores, performance year 2024
- 85of 100Final score
- 75.9of 100Quality
- 99of 100Promoting Interoperability
- 40of 100Improvement Activities
- 75of 100Cost
Each score is out of 100. The final score weighs the categories CMS scored for this clinician.
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. Hollis W. Walker has 12 publications on record
Dmand AI links 12 papers to Dr. Walker, published from 2015 to 2020. 2016 was the busiest year, with 2. The most frequent topics are Streptococcus pneumoniae, Drug Resistance, Bacterial and Pneumococcal Infections. Dr. Walker has published most often in Clin Microbiol Infect. Dr. Walker's most frequent co-authors are Ruth Lynfield, MD, Cynthia Gayle Whitney, MD, MPH and Lindsay Kim, MD, MPH.
Papers12
Years published2015 to 2020
Dr. Walker's papers by year, 2015 to 2020
Topics Dr. Walker writes about most
- Streptococcus pneumoniae
- Drug Resistance, Bacterial
- Pneumococcal Infections
- Serogroup
- Anti-Bacterial Agents
- Genotype
- Microbial Sensitivity Tests
- Genome, Bacterial
Dr. Walker's most frequent co-authors
- Ruth Lynfield, MD4 shared papers
- Cynthia Gayle Whitney, MD, MPH2 shared papers
- Lindsay Kim, MD, MPH1 shared paper
Recent publications by Dr. Walker
Clin Microbiol Infect
Anti-Bacterial AgentsBacterial Typing TechniquesDrug Resistance, Bacterial
Anti-Bacterial AgentsBacterial ProteinsDrug Resistance, Bacterial
See who Dr. Walker researches with
Physician Network Discovery turns co-authorship, shared hospitals and shared groups into a map of who Dr. Walker works with, so you can find a warm path to the right hematologists and oncologists.
Sources: PubMed (National Library of Medicine); and Dmand AI Research Linkage
Dr. Hollis W. Walker received $1,827 in industry payments from 2016 to 2025
CMS Open Payments shows 48 general payments to Dr. Walker from 19 drug and device companies from 2016 to 2025. Food and beverage make up the largest share, 95% of the total. Janssen Pharmaceuticals, Inc paid the most, $270.
General payments to Dr. Walker by program year, 2016 to 2025
General payments to Dr. Walker by kind, 2016 to 2025
$1.8Kin total
- Food and beverage$1,73795%
- Education$895%
Companies that paid Dr. Walker 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. Hollis W. Walker graduated from Clvlnd Clinic Lerner College of Med of Case Wstn Rsv University
Dr. Walker graduated from Clvlnd Clinic Lerner College of Med of Case Wstn Rsv University in 2010.
- Medical school
Source: Dmand AI Professional Profile Data
Sources for Dr. Hollis W. Walker'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) |
| 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 |
| 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. Hollis W. Walker
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. Hollis W. Walker's NPI number?
Dr. Hollis W. Walker's NPI number is 1053622290. It was assigned on June 22, 2010, and it is active in the NPI Registry.
What kind of doctor is Dr. Hollis W. Walker?
Dr. Hollis W. Walker is a hematologist and oncologist in Evanston, Illinois. The primary specialty in the NPI Registry is Hematology & Oncology Physician (taxonomy code 207RH0003X).
Where does Dr. Hollis W. Walker practice?
Dr. Walker practices at 2650 Ridge Ave, Evanston, IL 60201. Dr. Walker's primary practice is Evanston Hospital in Evanston, Illinois, part of Endeavor Health. Dmand AI also links Dr. Walker to 2 hospitals, 2 group practices and clinics and 1 medical group.
What is Dr. Hollis W. Walker's office phone number?
The practice phone on file for Dr. Walker is (847) 570-2000.
What is Dr. Hollis W. Walker's medical license number?
Dr. Walker holds Illinois license 036.141268.
Which hospitals is Dr. Hollis W. Walker affiliated with?
Dr. Walker practices at Evanston Hospital in Evanston, Illinois. Dr. Walker is also affiliated with Swedish Hospital. Dmand AI links Dr. Walker to 2 more hospitals.
What medical group is Dr. Hollis W. Walker part of?
Dr. Walker is linked to Endeavor Health Medical Group. Dmand AI links Dr. Walker to 1 more medical group.
Does Dr. Hollis W. Walker accept Medicare?
Yes. CMS data shows Dr. Walker billed Medicare for 1,078 services in 2024, and Dr. Walker accepts Medicare assignment.
What is Dr. Hollis W. Walker's MIPS score?
Dr. Walker's MIPS final score for performance year 2024 is 85 out of 100, reported as part of a group.
How many Medicare patients does Dr. Hollis W. Walker see?
CMS counts 308 Medicare patients who saw Dr. Walker in 2024, with an average age of 76.
Show 7 more questionsShow fewer questions
What services does Dr. Hollis W. Walker bill to Medicare?
In 2024, Dr. Walker's most billed Medicare services were office visit, established patient (99215), office visit, established patient (99214) and medicare service (G2211).
Where did Dr. Hollis W. Walker go to medical school?
Dr. Walker graduated from Clvlnd Clinic Lerner College of Med of Case Wstn Rsv University in 2010.
What drugs does Dr. Hollis W. Walker prescribe most?
In 2024 Medicare Part D data, Dr. Walker's most prescribed drugs by claims were Eliquis, Xarelto and Lenalidomide.
Has Dr. Hollis W. Walker received payments from drug or device companies?
CMS Open Payments shows $1,827 in general payments to Dr. Walker from 19 companies from 2016 to 2025. The largest total came from Janssen Pharmaceuticals, Inc.
How long has Dr. Hollis W. Walker been practicing?
Dr. Walker graduated from medical school in 2010, 16 years ago.
Does Dr. Hollis W. Walker do research?
Dmand AI links 12 publications to Dr. Walker, published from 2015 to 2020.
Who does Dr. Hollis W. Walker publish with?
Dr. Walker's most frequent co-authors are Ruth Lynfield, MD (4 shared papers), Cynthia Gayle Whitney, MD, MPH (2 shared papers) and Lindsay Kim, MD, MPH (1 shared paper).
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