Dr. William R Harper , MD
Internal Medicine • Chicago, IL
737 N Michigan Ave, Suite 2020
Chicago, IL 60611
This profile restates public CMS/NPPES data; T-MedInfo gives no medical advice — consult a licensed professional, and call 911 for emergencies.
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Dr. William Harper is listed in NPPES under Internal Medicine.
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NPI assigned on December 18, 2006; this date does not establish years in practice.
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Published CMS data list 603 Medicare Part D prescriptions, including refills, in 2024.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2024. Published rows only; this is not a quality measure.
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Published Part D records, 2024:
- Rosuvastatin Calcium — 83 prescription fills, including refills.
- Atorvastatin Calcium — 51 prescription fills, including refills.
- Levothyroxine Sodium — 45 prescription fills, including refills.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2024. Drug names come from pharmacy claims. Listing a drug here is not an endorsement or a recommendation.
See all 26 records in the table · Guide: How to read Medicare Part D prescriber data
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Close to the middle for Part D prescriptions among clinicians listed under Internal Medicine in Chicago, IL (2024, 1,269 clinicians with data). Median for this group: 474. Middle half: 74 to 2,358.
Close to the middle for Part D prescriptions among clinicians listed under Internal Medicine in Illinois (2024, 3,755 clinicians with data). Median for this group: 1,030. Middle half: 99 to 4,658.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2024. Billing and prescribing volume is not a quality rating.
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Medicare Part D prescriptions went from 141 in 2020 to 603 in 2024.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2020–2024.
Practice Location & Contact Primary Location
737 N Michigan Ave
Suite 2020
Chicago, IL 60611
Matched by practice address or phone in NPPES. A shared address or phone does not confirm that this clinician works there.
What Public CMS Data Show
Internal Medicine: NPPES taxonomy is a reported classification, not proof of board certification.
30-day fills
1,143 standardized 30-day fills in 2024
CMS converts prescriptions to 30-day supplies so they can be compared. A 90-day prescription counts as about three 30-day fills.
What this does not show: 30-day fills
It is not a count of patients and not a measure of quality.
Part D drug cost
$59,658 in 2024
The total cost of these prescriptions in 2024, paid by Medicare drug plans, patients and other payers together.
It shows the total spending on drugs this clinician prescribed, not what any one patient paid.
What this does not show: Part D drug cost
A higher cost often reflects the type of medicines a specialty uses. It is not your out-of-pocket cost and not a measure of quality.
Source: CMS, Medicare Part D Prescribers – by Provider and Drug, 2024.
Industry payments (Open Payments)
Fewer than 11 payment records totaling $15.37 in 2025
Drug and medical device companies must report certain payments to doctors and some other clinicians to CMS, such as meals, travel, speaking fees or research funding.
It shows reported financial ties between this clinician and companies. You can ask your clinician about them.
These records are submitted by drug and medical device companies, and a reported payment does not necessarily mean the financial relationship is improper.
General: payments not tied to research, such as meals, travel, consulting or speaking fees.
A reported payment does not necessarily mean the financial relationship is improper. Research payments can go to a hospital or university for a study the clinician leads, not to the clinician personally. Clinicians can dispute records with the company that reported them.
Source: CMS Open Payments, program year 2025.
NPI first issued
2006
The year this clinician's National Provider Identifier (NPI) was issued. An NPI is a unique 10-digit ID that US health care providers use for billing.
What this does not show: NPI first issued
NPIs have been issued only since 2005, so this year is not necessarily when the clinician started practicing.
Source: CMS NPPES NPI Registry.
Medicare assignment not listed
CMS data do not show whether this clinician accepts Medicare assignment. This does not mean they do not accept Medicare. Ask the office.
Medicare assignment applies to Original Medicare. It does not tell you whether the clinician is in a Medicare Advantage plan's network, accepts other insurance, or is taking new patients.
Source: CMS Doctors and Clinicians; Medicare.gov, “Does your provider accept Medicare as full payment?”
No telehealth indicator
CMS shows this indicator only when recent Medicare claims include telehealth services. The clinician may still offer telehealth; ask the office.
Source: CMS, Telehealth Indicator on Medicare Care Compare (fact sheet, January 2023); CMS Doctors and Clinicians.
Can order Medicare-covered services
CMS lists Dr. Harper as eligible to order or refer Medicare Part B clinical laboratory and imaging services, durable medical equipment (DME) and home health services for people with Medicare.
Medicare pays for these items and services only when they are ordered by an eligible clinician.
What this does not show: Can order Medicare-covered services
It does not mean the clinician offers these services directly.
Source: CMS Medicare Fee-For-Service Public Provider Enrollment (PECOS); CMS Order and Referring file.
Compared with the same specialty in Chicago and Illinois
Billing and prescribing volume is not a quality rating.
Medicare Part D prescriptions
Close to the middle for clinicians listed under Internal Medicine in Chicago, IL (2024, 1,269 clinicians with data). Median for this group: 474. Middle half: 74 to 2,358.
Close to the middle for clinicians listed under Internal Medicine in Illinois (2024, 3,755 clinicians with data). Median for this group: 1,030. Middle half: 99 to 4,658.
Part D drug cost
Close to the middle for clinicians listed under Internal Medicine in Chicago, IL (2024, 1,269 clinicians with data). Median for this group: $40,678. Middle half: $1,543 to $232,098.
Close to the middle for clinicians listed under Internal Medicine in Illinois (2024, 3,755 clinicians with data). Median for this group: $78,716. Middle half: $2,604 to $371,507.
2,870 active clinicians are listed under Internal Medicine with a practice address in Chicago, IL (7,245 in Illinois).
Addresses are self-reported to NPPES and may be out of date.
Telehealth indicator in Chicago
13.3% of these 2,870 clinicians have the CMS telehealth indicator.
38.5% of these 2,870 clinicians are listed by CMS as accepting Medicare assignment.
CMS data by year
Changes may reflect reporting, coverage or privacy limits, not changes in care quality.
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Medicare Part D prescriptions
Medicare Part D prescriptions increased 328% from 141 in 2020 to 603 in 2024.
- 2020: 141
- 2021: 163
- 2022: 236
- 2023: 414
- 2024: 603
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30-day fills
30-day fills increased 297% from 288 in 2020 to 1,143 in 2024.
- 2020: 288
- 2021: 426
- 2022: 588
- 2023: 898
- 2024: 1,143
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Part D drug cost
Part D drug cost increased 1786% from $3,164 in 2020 to $59,658 in 2024.
- 2020: $3,164
- 2021: $3,397
- 2022: $17,530
- 2023: $43,945
- 2024: $59,658
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Industry payments (Open Payments)
Industry payments (Open Payments) went from $21.93 in 2021 to $15.37 in 2025.
- 2021: $21.93
- 2022: $67.14
- 2023: $23.38
- 2024: $13.30
- 2025: $15.37
Sources: CMS Medicare Part D Prescribers (2024), CMS Open Payments (2025), CMS Doctors and Clinicians, CMS NPPES NPI Registry. Specialty names follow the NUCC Health Care Provider Taxonomy.
Text: T-MedInfo · Report an error.
Pharma & Medical Device Financial Disclosures
Payments and other transfers of value that drug and medical device companies reported to CMS Open Payments
Program year 2025 (payments made January 1 – December 31, 2025): fewer than 11 records totaling $15.37.
| Manufacturer | Payment Nature | Product | Type | Amount ($) |
|---|---|---|---|---|
| Novo Nordisk Inc |
Food and Beverage
In-kind items and services
|
Wegovy | General | $15.37 |
Source: CMS Open Payments, program year 2025, released June 30, 2026.
Medicare Part D Prescribing Profile & Medications
Medicare Part D prescriptions filled, including refills, in 2024.
| Brand Name | Generic Name | Prescriptions | Day Supply | Total Cost | Patients |
|---|---|---|---|---|---|
| Rosuvastatin Calcium | Rosuvastatin Calcium | 83 | 6,029 | $1,371.86 | 22 |
| Atorvastatin Calcium | Atorvastatin Calcium | 51 | 3,990 | $269.41 | 11 |
| Levothyroxine Sodium | Levothyroxine Sodium | 45 | 3,940 | $737.27 | 13 |
| Bupropion Xl | Bupropion Hcl | 36 | 1,718 | $989.39 | — |
| Finasteride | Finasteride | 26 | 1,298 | $412.83 | — |
| Metoprolol Succinate | Metoprolol Succinate | 26 | 1,560 | $423.16 | — |
| Eliquis | Apixaban | 26 | 1,370 | $26,332.93 | — |
| Irbesartan | Irbesartan | 25 | 1,530 | $204.15 | — |
| Alendronate Sodium | Alendronate Sodium | 21 | 1,008 | $120.24 | — |
| Losartan Potassium | Losartan Potassium | 21 | 1,170 | $151.33 | — |
| Omeprazole | Omeprazole | 21 | 630 | $113.17 | — |
| Pantoprazole Sodium | Pantoprazole Sodium | 21 | 1,350 | $289.07 | — |
| Metformin Hcl Er | Metformin Hcl | 21 | 750 | $110.41 | — |
| Myrbetriq | Mirabegron | 19 | 527 | $8,450.69 | — |
| Metformin Hcl | Metformin Hcl | 17 | 1,530 | $166.84 | — |
| Xarelto | Rivaroxaban | 16 | 660 | $12,731.87 | — |
| Pravastatin Sodium | Pravastatin Sodium | 16 | 780 | $4.59 | — |
| Amlodipine Besylate-Benazepril | Amlodipine Besylate/Benazepril | 14 | 720 | $195.18 | — |
| Sildenafil Citrate | Sildenafil Citrate | 14 | 348 | $28.96 | — |
| Abrysvo | Rsv Vacc, Pref A And Pref B/Pf | 14 | 130 | $4,534.90 | 14 |
| Famotidine | Famotidine | 13 | 488 | $447.07 | — |
| Aripiprazole | Aripiprazole | 13 | 390 | $134.89 | — |
| Hydrocodone-Acetaminophen | Hydrocodone/Acetaminophen | 11 | 330 | $223.22 | — |
| Sertraline Hcl | Sertraline Hcl | 11 | 813 | $255.61 | — |
| Potassium Chloride | Potassium Chloride | 11 | 330 | $87.10 | — |
(top 25 shown)
Source: CMS Part D by Provider and Drug, 2024; rows below 11 claims omitted by CMS; volume isn’t quality. Privacy limits
Specialties & License Numbers Reported to NPPES
NUCC Taxonomy Code: 207R00000X
A physician who provides long-term, comprehensive care in the office and the hospital, managing both common and complex illness of adolescents, adults and the elderly. Internists are trained in the diagnosis and treatment of cancer, infections and diseases affecting the heart, blood, kidneys, joints and digestive, respiratory and vascular systems. They are also trained in the essentials of primary care internal medicine, which incorporates an understanding of disease prevention, wellness, substance abuse, mental health and effective treatment of common problems of the eyes, ears, skin, nervous system and reproductive organs.
Additional State Medicaid & Healthcare Payer Identifiers
Medicare (PECOS) Enrollment & Ordering Eligibility
Source: CMS PECOSSources: CMS Provider Enrollment and Order and Referring. Medicare enrollment is a billing status, not an accreditation or quality rating.
Clinicians Sharing This Practice Address or Phone
Clinicians sharing this NPPES address, phone or fax; a shared contact does not mean they work together.
Internal Medicine
Doctor of Medicine (M.D.)
Internal Medicine
Doctor of Medicine (M.D.)
Internal Medicine
Doctor of Medicine (M.D.)
Nurse Practitioner - Family
Advanced Practice Nurse, Family Nurse Practitioner (Board Certified)
Career & Practice History Timeline
Changes recorded in monthly NPPES data files: addresses, names, credentials, specialties and NPI status
Registered at 737 N MICHIGAN AVE, SUITE 2020, CHICAGO, IL 60611 (Tel: 8559477371)
NPI status registered as active in NPPES database
Registered at 737 N MICHIGAN AVE, SUITE 2020, CHICAGO, IL 606112615 (Tel: 8559477371)
Registered at 5119 S DORCHESTER AVE, CHICAGO, IL 606154117 (Tel: 8559477371)
Recorded as WILLIAM HARPER, MD
Internal Medicine (license number reported to NPPES: IL 036097080)
NPI status registered as active in NPPES database
Registered at 180 HARVESTER DR STE 110, BURR RIDGE, IL 605276686 (Tel: 7738344064)
Registered at 5841 S MARYLAND AVE # MC1099, CHICAGO, IL 606371447
Recorded as WILLIAM HARPER, MD
Internal Medicine
First registered as active Individual Practitioner in NPPES Database.
NPI Administrative Meta
Other Internal Medicine Providers in Chicago
- Dr. Mandakini Pokharna, MD
- Dr. Jessica Lowe, MD
- Dr. Gregory Vachon, MD
- Dr. John Patrick Uy, MD
- Meredith Kline
- Dr. Amna Ali, MD
Mailing Address
5119 S Dorchester Ave
Chicago, IL 606154117
Phone: 8559477371