Dr. Thomas Edwin Klarquist , MD
Internal Medicine โข Chicago, IL
3134 N Clark St
Chicago, IL 606574414
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. Thomas Klarquist is listed in NPPES under Internal Medicine.
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NPI assigned on April 17, 2006; this date does not establish years in practice.
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Published CMS data list 915 Original Medicare Part B services in 2024.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2024. Published rows only; this is not a quality measure.
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Published Part B service records, 2024:
- 99214 โ Established patient outpatient office visit: 235 service units.
- 36415 โ Insertion of needle into vein for collection of blood sample: 228 service units.
- G0439 โ Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit: 107 service units.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2024. Units differ by code; these are not visits or a measure of quality.
CPTยฎ only copyright 2023 American Medical Association. All rights reserved. Service names are shortened from CPT Consumer Friendly Descriptors (CMS data, 2024). CPT notice
See all 14 records in the table ยท Guide: How to read Medicare Part B data
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Published CMS data list 3,160 Medicare Part D prescriptions, including refills, in 2024.
Source: CMS, Medicare Part D Prescribers โ by Provider and Drug, 2024. Published rows only; this is not a quality measure.
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Published Part D records, 2024:
- Atorvastatin Calcium โ 317 prescription fills, including refills.
- Lisinopril โ 182 prescription fills, including refills.
- Amlodipine Besylate โ 138 prescription fills, including refills.
Source: CMS, Medicare Part D Prescribers โ by Provider and Drug, 2024. Drug names come from pharmacy claims. Listing a drug here is not an endorsement or a recommendation.
See all 85 records in the table ยท Guide: How to read Medicare Part D prescriber data
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More Medicare Part B services than 75% of clinicians listed under Internal Medicine in Chicago, IL (2024, 1,008 clinicians with data). Median for this group: 406. Middle half: 157 to 820.
More Medicare Part B services than 60% of clinicians listed under Internal Medicine in Illinois (2024, 3,249 clinicians with data). Median for this group: 699. Middle half: 285 to 1,340.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2024. Billing and prescribing volume is not a quality rating.
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Medicare Part B services went from 399 in 2020 to 915 in 2024.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2020โ2024.
Practice Location & Contact Primary Location
3134 N Clark St
Chicago, IL 606574414
Matched by practice address or phone in NPPES. A shared address or phone does not confirm that this clinician works there.
NPPES lists 1 additional practice-address record in Palm Springs, CA. See the list
Source: CMS NPPES NPI Registry, practice location records; release date unavailable.
CMS Doctors and Clinicians lists 1 group name: Advocate Health And Hospitals Corporation. See the list
Source: CMS Doctors and Clinicians National Downloadable File, release date unavailable.
Listings do not confirm current availability, employment or a shared ownership network.
Medicare Profile & Education
Source: CMS Doctors and Clinicians National Downloadable File
Michigan State University College Of Human Medicine
1987
What Public CMS Data Show
Internal Medicine: NPPES taxonomy is a reported classification, not proof of board certification.
Medicare patients
175 people with Original Medicare in 2024
It gives a sense of how many people with Medicare this clinician treated that year.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider, 2024.
Medicare-allowed amount
About $73,938 in 2024
The total amount Medicare approved for these services in 2024. It includes what Medicare paid and what patients or their other insurance owed, such as the deductible and coinsurance.
It shows the total cost of this clinician's Original Medicare services under Medicare's fee rules.
What this does not show: Medicare-allowed amount
This is not the clinician's income. Part of it can go to a clinic or group practice, staff, equipment or drugs. It is not the price you will pay.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2024.
Paid by Medicare
About $62,719 in 2024
The part of the Medicare-allowed amount that Medicare itself paid in 2024, after patients' deductibles and coinsurance.
The gap between the allowed amount and this number is roughly what patients and their other insurance paid.
What this does not show: Paid by Medicare
This is not the clinician's income and not a measure of quality.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2024.
30-day fills
7,205 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
$1,644,919 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 โ by Provider and Drug, 2024.
Open Payments general payments, program year 2023
All general payments: $87.20 across 4 records.
By nature of payment
- Food and Beverage: $58.72 across 3 records.
- Education: $28.48 across 1 record.
Reporting-company totals
- ViiV Healthcare Company: $58.72 across 3 records.
- Janssen Pharmaceuticals, Inc: $28.48 across 1 record.
A reported payment does not necessarily mean the financial relationship is improper and is not a measure of care quality. Clinicians can review and dispute these records.
Source: Calculated by T-MedInfo from CMS Open Payments general-payment records for program year 2023 (published June 30, 2026).
Years since graduation
39 years (graduated 1987)
CMS Doctors and Clinicians data list 1987 as the year this clinician finished professional school.
It tells you roughly how long ago the clinician finished school.
What this does not show: Years since graduation
It is not the number of years in practice, and more years does not mean better care.
Source: CMS Doctors and Clinicians National Downloadable File.
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.
Accepts Medicare assignment
CMS data list this clinician as accepting Medicare assignment. This means agreeing to take the Medicare-approved amount as full payment for covered services.
With Original Medicare, you usually pay only your deductible and coinsurance, and the office sends the claim to Medicare for you.
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, โDoes your provider accept Medicare as full payment?โ
Telehealth (some services)
Recent Medicare claims show this clinician provided some services by telehealth, such as a video or phone visit.
You may be able to have some visits without going to the office. Ask which visits can be done by telehealth.
What this does not show: Telehealth (some services)
It does not mean all services are offered by telehealth, or that telehealth is covered by your plan.
Source: CMS, Telehealth Indicator on Medicare Care Compare (fact sheet, January 2023); CMS Doctors and Clinicians.
Enrolled in Medicare (PECOS)
Dr. Klarquist has a Medicare enrollment record in PECOS, the CMS system clinicians use to enroll so they can bill Medicare or order services for people with Medicare.
It does not show whether the clinician accepts assignment, is in your plan's network, or is taking new patients.
Source: CMS Medicare Fee-For-Service Public Provider Enrollment (PECOS); CMS Order and Referring file.
Can order Medicare-covered services
CMS lists Dr. Klarquist 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 B services
More Medicare Part B services than 75% of clinicians listed under Internal Medicine in Chicago, IL (2024, 1,008 clinicians with data). Median for this group: 406. Middle half: 157 to 820.
More Medicare Part B services than 60% of clinicians listed under Internal Medicine in Illinois (2024, 3,249 clinicians with data). Median for this group: 699. Middle half: 285 to 1,340.
Medicare-allowed amount
A higher Medicare-allowed amount than 70% of clinicians listed under Internal Medicine in Chicago, IL (2024, 1,008 clinicians with data). Median for this group: $41,573. Middle half: $14,662 to $79,189.
Close to the middle for clinicians listed under Internal Medicine in Illinois (2024, 3,249 clinicians with data). Median for this group: $67,802. Middle half: $27,619 to $124,679.
Paid by Medicare
A higher Medicare payment amount than 75% of clinicians listed under Internal Medicine in Chicago, IL (2024, 1,008 clinicians with data). Median for this group: $31,519. Middle half: $10,954 to $62,185.
Close to the middle for clinicians listed under Internal Medicine in Illinois (2024, 3,249 clinicians with data). Median for this group: $52,838. Middle half: $21,117 to $98,214.
Medicare Part D prescriptions
More Part D prescriptions than 80% of 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.
More Part D prescriptions than 65% of 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
A higher Part D drug cost than 95% of 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.
A higher Part D drug cost than 95% of 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 B services
Medicare Part B services increased 129% from 399 in 2020 to 915 in 2024.
- 2020: 399
- 2021: 472
- 2022: 503
- 2023: 792
- 2024: 915
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Medicare-allowed amount
Medicare-allowed amount increased 103% from $36,365 in 2020 to $73,938 in 2024.
- 2020: $36,365
- 2021: $51,861
- 2022: $53,692
- 2023: $67,846
- 2024: $73,938
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Paid by Medicare
Paid by Medicare increased 133% from $26,969 in 2020 to $62,719 in 2024.
- 2020: $26,969
- 2021: $39,697
- 2022: $43,644
- 2023: $56,081
- 2024: $62,719
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Medicare Part D prescriptions
Medicare Part D prescriptions increased 18% from 2,667 in 2020 to 3,160 in 2024.
- 2020: 2,667
- 2021: 2,959
- 2022: 3,363
- 2023: 3,174
- 2024: 3,160
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30-day fills
30-day fills increased 29% from 5,564 in 2020 to 7,205 in 2024.
- 2020: 5,564
- 2021: 6,430
- 2022: 7,486
- 2023: 7,330
- 2024: 7,205
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Part D drug cost
Part D drug cost increased 64% from $1,000,368 in 2020 to $1,644,919 in 2024.
- 2020: $1,000,368
- 2021: $1,102,137
- 2022: $1,456,281
- 2023: $1,678,113
- 2024: $1,644,919
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Industry payments (Open Payments)
CMS data for industry payments (Open Payments) are available for 2023 only.
Sources: CMS Medicare Physician & Other Practitioners (2024), CMS Medicare Part D Prescribers (2024), CMS Open Payments (2023), CMS Doctors and Clinicians, CMS NPPES NPI Registry. Specialty names follow the NUCC Health Care Provider Taxonomy.
Text: T-MedInfo ยท 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 2023 (payments made January 1 โ December 31, 2023): fewer than 11 records totaling $87.20.
| Manufacturer | Payment Nature | Product | Type | Amount ($) |
|---|---|---|---|---|
| ViiV Healthcare Company |
Food and Beverage
In-kind items and services
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APRETUDE | General | $32.11 |
| Janssen Pharmaceuticals, Inc |
Education
In-kind items and services
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โ | General | $28.48 |
| ViiV Healthcare Company |
Food and Beverage
In-kind items and services
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APRETUDE | General | $13.88 |
| ViiV Healthcare Company |
Food and Beverage
In-kind items and services
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CABENUVA | General | $12.73 |
Source: CMS Open Payments, program year 2023, released June 30, 2026.
Performed Procedures & Service Volume
CPTยฎ is a registered trademark of the American Medical Association. CPT codes, descriptions and other data only are copyright 2016โ2023 American Medical Association. All rights reserved. Applicable FARS/HHSARS apply. Descriptions of CPT codes are the AMA's CPT Consumer Friendly Descriptors as published by CMS in the Medicare Physician & Other Practitioners โ by Provider and Service data, 2017โ2024; they are plain-language summaries, not for clinical coding or documentation. HCPCS Level II codes and descriptions are from CMS. Fee schedules, relative value units, conversion factors and/or related components are not assigned by the AMA, are not part of CPT, and the AMA is not recommending their use. The AMA does not directly or indirectly practice medicine or dispense medical services. The AMA assumes no liability for data contained or not contained herein.
| HCPCS Code | Services | Patients | Submitted Charge | Medicare Allowed |
|---|---|---|---|---|
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99214
Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more
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235 | 136 | $279.00 | $130.08 |
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36415
Insertion of needle into vein for collection of blood sample
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228 | 140 | $22.00 | $8.42 |
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G0439
Annual wellness visit, includes a personalized prevention plan of service (pps), subsequent visit
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107 | 107 | $332.00 | $129.56 |
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99213
Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more
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86 | 73 | $198.00 | $93.25 |
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G2211
Visit complexity inherent to evaluation and management associated with medical care services that serve as the continuing focal point for all needed health care services and/or with medical care services that are part of ongoing care related to a patient's
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41 | 37 | $35.00 | $16.87 |
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90662
Influenza vaccine split virus, preservative free
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34 | 34 | $125.00 | $76.13 |
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G0008
Administration of influenza virus vaccine
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34 | 34 | $60.00 | $33.70 |
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83036
Hemoglobin a1c level
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33 | 19 | $68.00 | $8.94 |
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90480
Admn sarscov2 vacc 1 dose
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30 | 27 | $85.00 | $41.94 |
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91322
Sarscov2 vac 50 mcg/0.5ml im
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30 | 27 | $250.00 | $144.26 |
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G0402
Initial preventive physical examination; face-to-face visit, services limited to new beneficiary during the first 12 months of medicare enrollment
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16 | 16 | $371.00 | $169.83 |
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90677
Pneumococcal conjugate vaccine, 20 valent (pcv20), for intramuscular use
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14 | 14 | $489.29 | $288.14 |
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G0009
Administration of pneumococcal vaccine
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14 | 14 | $60.00 | $33.70 |
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G0438
Annual wellness visit; includes a personalized prevention plan of service (pps), initial visit
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13 | 13 | $498.00 | $156.73 |
Source: CMS Part B by Provider and Service, 2024; services under 11 beneficiaries omitted by CMS. Privacy limits
Submitted charges are billed amounts, not a price quote for your visit.
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 |
|---|---|---|---|---|---|
| Atorvastatin Calcium | Atorvastatin Calcium | 317 | 25,582 | $3,561.11 | 86 |
| Lisinopril | Lisinopril | 182 | 15,471 | $1,520.92 | 55 |
| Amlodipine Besylate | Amlodipine Besylate | 138 | 11,800 | $1,126.60 | 40 |
| Levothyroxine Sodium | Levothyroxine Sodium | 108 | 7,999 | $1,128.94 | 28 |
| Metformin Hcl | Metformin Hcl | 96 | 7,440 | $762.46 | 24 |
| Metoprolol Succinate | Metoprolol Succinate | 93 | 7,940 | $2,353.25 | 27 |
| Dovato | Dolutegravir Sodium/Lamivudine | 79 | 2,610 | $257,425.43 | โ |
| Losartan Potassium | Losartan Potassium | 70 | 6,134 | $684.93 | 21 |
| Gabapentin | Gabapentin | 66 | 3,599 | $1,229.82 | 21 |
| Hydrochlorothiazide | Hydrochlorothiazide | 66 | 5,696 | $414.38 | 21 |
| Alprazolam | Alprazolam | 64 | 1,429 | $159.26 | 20 |
| Lantus Solostar | Insulin Glargine,hum.Rec.Anlog | 62 | 3,530 | $7,301.90 | 13 |
| Simvastatin | Simvastatin | 61 | 5,420 | $494.81 | 17 |
| Biktarvy | Bictegrav/Emtricit/Tenofov Ala | 61 | 2,430 | $330,934.46 | โ |
| Zolpidem Tartrate | Zolpidem Tartrate | 60 | 1,905 | $212.19 | โ |
| Omeprazole | Omeprazole | 56 | 5,040 | $525.77 | 15 |
| Rosuvastatin Calcium | Rosuvastatin Calcium | 54 | 4,860 | $854.43 | 17 |
| Descovy | Emtricitabine/Tenofov Alafenam | 54 | 2,340 | $169,448.03 | โ |
| Tamsulosin Hcl | Tamsulosin Hcl | 50 | 3,620 | $922.25 | 16 |
| Lisinopril-Hydrochlorothiazide | Lisinopril/Hydrochlorothiazide | 47 | 4,170 | $378.83 | 14 |
| Jardiance | Empagliflozin | 47 | 2,790 | $55,088.54 | 11 |
| Albuterol Sulfate Hfa | Albuterol Sulfate | 47 | 1,319 | $2,116.38 | 15 |
| Famotidine | Famotidine | 46 | 3,480 | $493.00 | 13 |
| Metformin Hcl Er | Metformin Hcl | 44 | 3,600 | $681.93 | 12 |
| Genvoya | Elviteg/Cob/Emtri/Tenof Alafen | 42 | 1,560 | $217,982.21 | โ |
(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
Self-certified to NPPES: 2025-03-26NUCC 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.
Medicare (PECOS) Enrollment & Ordering Eligibility
Source: CMS PECOSPRACTITIONER - INTERNAL MEDICINE
I20040924000628
IL
5991774184
Sources: CMS Provider Enrollment and Order and Referring. Medicare enrollment is a billing status, not an accreditation or quality rating.
Medicare Group Practice Enrollments
Source: CMS Doctors and Clinicians National Downloadable File
Advocate Health And Hospitals Corporation
214 Mchenry Rd, Buffalo Grove, IL 600896748
Phone: 8474591160
Advocate Health And Hospitals Corporation
3134 N Clark St, Chicago, IL 606574414
Phone: 7732965420
Advocate Health And Hospitals Corporation
3936 N Milwaukee Ave, Chicago, IL 606412703
Phone: 7737366125
Secondary Practice Locations
1695 N Sunrise Way
Palm Springs, CA 922623701
Phone: 7603232118
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
Physician Assistant
Physician Assistant (Certified)
Internal Medicine - Endocrinology, Diabetes & Metabolism
Doctor of Medicine (M.D.)
Anesthesiology
Anesthesiology
Doctor of Medicine (M.D.), Doctor of Philosophy (Ph.D.)
Anesthesiology
Doctor of Medicine (M.D.)
Career & Practice History Timeline
Changes recorded in monthly NPPES data files: addresses, names, credentials, specialties and NPI status
Registered at 29373 NETWORK PL, CHICAGO, IL 606731293 (Tel: 8473905900)
Registered at 3134 N CLARK ST, CHICAGO, IL 606574414 (Tel: 7732965090)
Registered at 3000 N HALSTED ST STE 509, CHICAGO, IL 606575194 (Tel: 7732965090)
Registered at 3450 N LAKE SHORE DR APT 3701, CHICAGO, IL 606572865 (Tel: 7733543833)
NPI status registered as active in NPPES database
Registered at 111 N WABASH AVE, SUITE 600, CHICAGO, IL 606021903 (Tel: 3123320844)
Registered at 111 N WABASH AVE, SUITE 600, CHICAGO, IL 606021903 (Tel: 3123320844)
Recorded as THOMAS KLARQUIST, M.D.
Internal Medicine (license number reported to NPPES: IL 036100647)
First registered as active Individual Practitioner in NPPES Database.
NPI Administrative Meta
Other Internal Medicine Providers in Chicago
- Dr. Abdul Sattar, MD
- Dr. James Hall, MD
- Dr. Andrew Carlson, MD
- Dr. Haley Herman, MD
- Dr. Nicholas Stiso, MD
- Dr. Grace Lee, MD
Mailing Address
29373 Network Pl
Chicago, IL 606731293
Phone: 8473905900