Thomas Joseph Ahearn , PA-C
Physician Assistant • Warrenville, IL
27650 Ferry Rd Ste 110
Warrenville, IL 605553846
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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NPI assigned on September 29, 2015; this date does not establish years in practice.
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Published CMS data list 195 Original Medicare Part B services in 2024.
Source: CMS, Medicare Physician & Other Practitioners – by Provider and Service, 2024. Published rows only; this is not a quality measure.
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Published Part B service records, 2024:
- 99284 — Emergency department visit with moderate level of medical decision making: 94 service units.
- 99285 — Emergency department visit with high level of medical decision making: 73 service units.
- 99283 — Emergency department visit with low level of medical decision making: 15 service units.
Source: CMS, Medicare Physician & Other Practitioners – by Provider and Service, 2024. Units differ by code; these are not visits or a measure of quality.
CPT® 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 4 records in the table · Guide: How to read Medicare Part B data
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Published CMS data list 55 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:
- Hydrocodone-Acetaminophen (Hydrocodone/Acetaminophen) — 42 prescription fills, including refills.
- Cephalexin — 13 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 the full table · Guide: How to read Medicare Part D prescriber data
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More Medicare Part B services than 60% of clinicians listed under Physician Assistant in Warrenville, IL (2024, 21 clinicians with data). Median for this group: 100. Middle half: 66 to 583.
Close to the middle for Medicare Part B services among clinicians listed under Physician Assistant in Illinois (2024, 2,422 clinicians with data). Median for this group: 212. Middle half: 76 to 548.
Source: CMS, Medicare Physician & Other Practitioners – by Provider and Service, 2024. Billing and prescribing volume is not a quality rating.
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Medicare Part B services went from 217 in 2020 to 195 in 2024.
Source: CMS, Medicare Physician & Other Practitioners – by Provider and Service, 2020–2024.
Practice Location & Contact Primary Location
27650 Ferry Rd Ste 110
Warrenville, IL 605553846
Matched by practice address or phone in NPPES. A shared address or phone does not confirm that this clinician works there.
CMS Doctors and Clinicians lists 1 group name: Central Dupage Physician Group. 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
2015
What Public CMS Data Show
Physician Assistant: NPPES taxonomy is a reported classification, not proof of board certification.
Medicare patients
188 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 – by Provider, 2024.
Medicare-allowed amount
About $22,672 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 – by Provider and Service, 2024.
Paid by Medicare
About $17,919 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 – by Provider and Service, 2024.
30-day fills
55 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
$222 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.
Open Payments general payments, program year 2024
All general payments: $86.16 across 3 records.
By nature of payment
- Food and Beverage: $86.16 across 3 records.
Reporting-company totals
- Inari Medical, Inc.: $86.16 across 3 records.
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 2024 (published June 30, 2026).
Years since graduation
11 years (graduated 2015)
CMS Doctors and Clinicians data list 2015 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
2015
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, “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.
Enrolled in Medicare (PECOS)
Thomas Ahearn 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 Thomas Ahearn 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 Warrenville and Illinois
Billing and prescribing volume is not a quality rating.
Medicare Part B services
More Medicare Part B services than 60% of clinicians listed under Physician Assistant in Warrenville, IL (2024, 21 clinicians with data). Median for this group: 100. Middle half: 66 to 583.
Close to the middle for clinicians listed under Physician Assistant in Illinois (2024, 2,422 clinicians with data). Median for this group: 212. Middle half: 76 to 548.
Medicare-allowed amount
A higher Medicare-allowed amount than 65% of clinicians listed under Physician Assistant in Warrenville, IL (2024, 21 clinicians with data). Median for this group: $14,594. Middle half: $7,197 to $30,173.
Close to the middle for clinicians listed under Physician Assistant in Illinois (2024, 2,422 clinicians with data). Median for this group: $16,580. Middle half: $6,650 to $35,717.
Paid by Medicare
A higher Medicare payment amount than 65% of clinicians listed under Physician Assistant in Warrenville, IL (2024, 21 clinicians with data). Median for this group: $10,450. Middle half: $4,780 to $23,632.
A higher Medicare payment amount than 60% of clinicians listed under Physician Assistant in Illinois (2024, 2,422 clinicians with data). Median for this group: $12,415. Middle half: $4,894 to $26,472.
Medicare Part D prescriptions
Fewer Part D prescriptions than 60% of clinicians listed under Physician Assistant in Warrenville, IL (2024, 25 clinicians with data). Median for this group: 80. Middle half: 39 to 180.
Fewer Part D prescriptions than 75% of clinicians listed under Physician Assistant in Illinois (2024, 2,668 clinicians with data). Median for this group: 203. Middle half: 67 to 595.
Part D drug cost
A lower Part D drug cost than 75% of clinicians listed under Physician Assistant in Warrenville, IL (2024, 25 clinicians with data). Median for this group: $551. Middle half: $269 to $1,829.
A lower Part D drug cost than 85% of clinicians listed under Physician Assistant in Illinois (2024, 2,668 clinicians with data). Median for this group: $3,018. Middle half: $535 to $48,132.
35 active clinicians are listed under Physician Assistant with a practice address in Warrenville, IL (4,929 in Illinois).
Addresses are self-reported to NPPES and may be out of date.
Telehealth indicator in Warrenville
22.9% of these 35 clinicians have the CMS telehealth indicator.
85.7% of these 35 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 decreased 10% from 217 in 2020 to 195 in 2024.
- 2020: 217
- 2021: 207
- 2022: 234
- 2023: 215
- 2024: 195
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Medicare-allowed amount
Medicare-allowed amount stayed about the same: $23,367 in 2020 and $22,672 in 2024.
- 2020: $23,367
- 2021: $23,472
- 2022: $26,965
- 2023: $24,446
- 2024: $22,672
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Paid by Medicare
Paid by Medicare stayed about the same: $19,433 in 2020 and $17,919 in 2024.
- 2020: $19,433
- 2021: $18,866
- 2022: $20,911
- 2023: $18,730
- 2024: $17,919
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Medicare Part D prescriptions
Medicare Part D prescriptions increased 28% from 43 in 2020 to 55 in 2024.
- 2020: 43
- 2021: 48
- 2022: 63
- 2023: 73
- 2024: 55
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30-day fills
30-day fills increased 28% from 43 in 2020 to 55 in 2024.
- 2020: 43
- 2021: 48
- 2022: 63
- 2023: 73
- 2024: 55
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Part D drug cost
Part D drug cost went from $261 in 2020 to $222 in 2024.
- 2020: $261
- 2021: $259
- 2022: $334
- 2023: $262
- 2024: $222
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Industry payments (Open Payments)
Industry payments (Open Payments) went from $203.75 in 2022 to $86.16 in 2024.
- 2022: $203.75
- 2024: $86.16
Sources: CMS Medicare Physician & Other Practitioners (2024), CMS Medicare Part D Prescribers (2024), CMS Open Payments (2024), 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 2024 (payments made January 1 – December 31, 2024): fewer than 11 records totaling $86.16.
| Manufacturer | Payment Nature | Product | Type | Amount ($) |
|---|---|---|---|---|
| Inari Medical, Inc. |
Food and Beverage
In-kind items and services
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FLOWTRIEVER CATHETER, S | General | $46.58 |
| Inari Medical, Inc. |
Food and Beverage
In-kind items and services
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FLOWTRIEVER CATHETER, S | General | $22.14 |
| Inari Medical, Inc. |
Food and Beverage
In-kind items and services
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FLOWTRIEVER CATHETER, S | General | $17.44 |
Source: CMS Open Payments, program year 2024, released June 30, 2026.
Performed Procedures & Service Volume
CPT® is a registered trademark of the American Medical Association. CPT codes, descriptions and other data only are copyright 2016–2023 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 – by Provider and Service data, 2017–2024; 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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99284
Emergency department visit with moderate level of medical decision making
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94 | 92 | $963.16 | $108.24 |
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99285
Emergency department visit with high level of medical decision making
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73 | 71 | $1172.99 | $156.76 |
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99283
Emergency department visit with low level of medical decision making
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15 | 15 | $666.00 | $63.82 |
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93010
Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only
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13 | 11 | $54.38 | $7.45 |
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 |
|---|---|---|---|---|---|
| Hydrocodone-Acetaminophen | Hydrocodone/Acetaminophen | 42 | 162 | $158.01 | 41 |
| Cephalexin | Cephalexin | 13 | 83 | $64.04 | 13 |
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: 2025-12-18NUCC Taxonomy Code: 363A00000X
A physician assistant is a person who has successfully completed an accredited education program for physician assistant, is licensed by the state and is practicing within the scope of that license. Physician assistants are formally trained to perform many of the routine, time-consuming tasks a physician can do. In some states, they may prescribe medications. They take medical histories, perform physical exams, order lab tests and x-rays, and give inoculations. Most states require that they work under the supervision of a physician.
NUCC Taxonomy Code: 363A00000X
A physician assistant is a person who has successfully completed an accredited education program for physician assistant, is licensed by the state and is practicing within the scope of that license. Physician assistants are formally trained to perform many of the routine, time-consuming tasks a physician can do. In some states, they may prescribe medications. They take medical histories, perform physical exams, order lab tests and x-rays, and give inoculations. Most states require that they work under the supervision of a physician.
Medicare (PECOS) Enrollment & Ordering Eligibility
Source: CMS PECOSPRACTITIONER - PHYSICIAN ASSISTANT
I20251103001317
IL
9830409317
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
Central Dupage Physician Group
27650 Ferry Rd, Warrenville, IL 605553845
Phone: 6302252663
Clinicians Sharing This Practice Address or Phone
Clinicians sharing this NPPES address, phone or fax; a shared contact does not mean they work together.
Family Medicine
Physician Assistant
Physician Assistant
Career & Practice History Timeline
Changes recorded in monthly NPPES data files: addresses, names, credentials, specialties and NPI status
Registered at 27650 FERRY RD STE 110, WARRENVILLE, IL 605553846 (Tel: 6303156543)
Registered at 27650 FERRY RD STE 110, WARRENVILLE, IL 605553846 (Tel: 6303156543)
Physician Assistant (license number reported to NPPES: IL 085006089)
NPI status registered as active in NPPES database
Registered at 400 N PEPPER AVE, COLTON, CA 923241801 (Tel: 9095801000)
Registered at 450 W FOOTHILL BLVD, #30, POMONA, CA 917671068 (Tel: 8158300914)
Recorded as THOMAS AHEARN, PA-C
Physician Assistant (license number reported to NPPES: CA 1128403)
First registered as active Individual Practitioner in NPPES Database.
NPI Administrative Meta
Other Physician Assistants in Warrenville
- Alyssa Micek, PA-C
- Christopher Kwong, PA
- Kristina Hougsted
- Rebecca Maczko, PA
- Kristine Torio, PA
- Nicole Warren, PA-C
Mailing Address
27650 Ferry Rd Ste 110
Warrenville, IL 605553846
Phone: 6303156543