Ellen Ang Gao , APN-CNP
Nurse Practitioner โข Evanston, IL
2650 Ridge Ave
Evanston, IL 60201
This profile restates public CMS/NPPES data; T-MedInfo gives no medical advice — consult a licensed professional, and call 911 for emergencies.
-
NPI assigned on August 5, 2019; this date does not establish years in practice.
-
Published CMS data list 45 Original Medicare Part B services in 2020.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2020. Published rows only; this is not a quality measure.
-
Published Part B service records, 2020:
- 99214 โ Established patient outpatient office visit: 33 service units.
- 99215 โ Established patient outpatient office visit: 12 service units.
Source: CMS, Medicare Physician & Other Practitioners โ by Provider and Service, 2020. Units differ by code; these are not visits or a measure of quality.
CPTยฎ only copyright 2019 American Medical Association. All rights reserved. Service names are shortened from CPT Consumer Friendly Descriptors (CMS data, 2020). CPT notice
See the full table ยท Guide: How to read Medicare Part B data
-
Published CMS data list 24 Medicare Part D prescriptions, including refills, in 2021.
Source: CMS, Medicare Part D Prescribers โ by Provider and Drug, 2021. Published rows only; this is not a quality measure.
-
Published Part D records, 2021:
- Fluoxetine Hcl โ 13 prescription fills, including refills.
- Sertraline Hcl โ 11 prescription fills, including refills.
Source: CMS, Medicare Part D Prescribers โ by Provider and Drug, 2021. Drug names come from pharmacy claims. Listing a drug here is not an endorsement or a recommendation.
See the full table ยท Guide: How to read Medicare Part D prescriber data
-
Medicare Part D prescriptions went from 61 in 2020 to 24 in 2021.
Source: CMS, Medicare Part D Prescribers โ by Provider and Drug, 2020โ2021.
Practice Location & Contact Primary Location
2650 Ridge Ave
Evanston, IL 60201
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 Andover, MA. See the list
Source: CMS NPPES NPI Registry, practice location records; release date unavailable.
Listings do not confirm current availability, employment or a shared ownership network.
What Public CMS Data Show
Nurse Practitioner: NPPES taxonomy is a reported classification, not proof of board certification.
Medicare-allowed amount
About $3,624 in 2020
The total amount Medicare approved for these services in 2020. 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, 2020.
Paid by Medicare
About $2,899 in 2020
The part of the Medicare-allowed amount that Medicare itself paid in 2020, 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, 2020.
30-day fills
41 standardized 30-day fills in 2021
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
$578 in 2021
The total cost of these prescriptions in 2021, 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, 2021.
Open Payments general payments, program year 2021
All general payments: $40.15 across 2 records.
By nature of payment
- Food and Beverage: $40.15 across 2 records.
Reporting-company totals
- Neurocrine Biosciences, Inc.: $23.31 across 1 record.
- AbbVie Inc.: $16.84 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 2021 (published June 30, 2026).
NPI first issued
2019
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, โDoes your provider accept Medicare as full payment?โ
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.
Compared with the same specialty in Evanston and Illinois
Billing and prescribing volume is not a quality rating.
Medicare Part B
Comparisons use 2024 data. The latest CMS data for Ellen Gao are from 2020.
Medicare Part D
Comparisons use 2024 data. The latest CMS data for Ellen Gao are from 2021.
139 active clinicians are listed under Nurse Practitioner with a practice address in Evanston, IL (4,894 in Illinois).
Addresses are self-reported to NPPES and may be out of date.
Telehealth indicator in Evanston
21.6% of these 139 clinicians have the CMS telehealth indicator.
71.9% of these 139 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.
-
Medicare Part B services
CMS data for Medicare Part B services are available for 2020 only.
-
Medicare-allowed amount
CMS data for Medicare-allowed amount are available for 2020 only.
-
Paid by Medicare
CMS data for Medicare payment amount are available for 2020 only.
-
Medicare Part D prescriptions
Medicare Part D prescriptions decreased 61% from 61 in 2020 to 24 in 2021.
- 2020: 61
- 2021: 24
-
30-day fills
30-day fills decreased 54% from 90 in 2020 to 41 in 2021.
- 2020: 90
- 2021: 41
-
Part D drug cost
Part D drug cost decreased 52% from $1,211 in 2020 to $578 in 2021.
- 2020: $1,211
- 2021: $578
-
Industry payments (Open Payments)
CMS data for industry payments (Open Payments) are available for 2021 only.
Sources: CMS Medicare Physician & Other Practitioners (2020), CMS Medicare Part D Prescribers (2021), CMS Open Payments (2021), 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 2021 (payments made January 1 โ December 31, 2021): fewer than 11 records totaling $40.15.
| Manufacturer | Payment Nature | Product | Type | Amount ($) |
|---|---|---|---|---|
| Neurocrine Biosciences, Inc. |
Food and Beverage
In-kind items and services
|
INGREZZA | General | $23.31 |
| AbbVie Inc. |
Food and Beverage
In-kind items and services
|
VRAYLAR | General | $16.84 |
Source: CMS Open Payments, program year 2021, 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 2019 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, 2020; 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 |
|---|---|---|---|---|
|
99214
Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more
|
33 | 18 | $238.39 | $72.59 |
|
99215
Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more
|
12 | 12 | $304.25 | $102.41 |
Source: CMS Part B by Provider and Service, 2020; 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 2021.
| Brand Name | Generic Name | Prescriptions | Day Supply | Total Cost | Patients |
|---|---|---|---|---|---|
| Fluoxetine Hcl | Fluoxetine Hcl | 13 | 570 | $433.07 | โ |
| Sertraline Hcl | Sertraline Hcl | 11 | 660 | $144.85 | โ |
Source: CMS Part D by Provider and Drug, 2021; rows below 11 claims omitted by CMS; volume isn’t quality. Privacy limits
Specialties & License Numbers Reported to NPPES
NUCC Taxonomy Code: 363L00000X
(1) A registered nurse provider with a graduate degree in nursing prepared for advanced practice involving independent and interdependent decision making and direct accountability for clinical judgment across the health care continuum or in a certified specialty. (2) A registered nurse who has completed additional training beyond basic nursing education and who provides primary health care services in accordance with state nurse practice laws or statutes. Tasks performed by nurse practitioners vary with practice requirements mandated by geographic, political, economic, and social factors. Nurse practitioner specialists include, but are not limited to, family nurse practitioners, gerontological nurse practitioners, pediatric nurse practitioners, obstetric-gynecologic nurse practitioners, and school nurse practitioners.
Secondary Practice Locations
25 Lincoln Cir W
Andover, MA 018102906
Phone: 9788072611
Clinicians Sharing This Practice Address or Phone
Clinicians sharing this NPPES address, phone or fax; a shared contact does not mean they work together.
Social Worker - Clinical
Licensed Clinical Social Worker
Psychiatry & Neurology - Psychiatry
Doctor of Medicine (M.D.)
Clinical Neuropsychologist
Doctor of Philosophy (Ph.D.)
Psychologist - Cognitive & Behavioral
Doctor of Philosophy (Ph.D.)
Psychiatry & Neurology - Child & Adolescent Psychiatry
Doctor of Medicine (M.D.)
Psychiatry & Neurology - Psychiatry
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 2650 RIDGE AVE, EVANSTON, IL 60201 (Tel: 8474256400)
Registered at 2650 RIDGE AVE, EVANSTON, IL 602011700 (Tel: 8474256400)
Recorded as ELLEN GAO, APN-CNP
Nurse Practitioner (license number reported to NPPES: IL 209019665)
NPI status registered as active in NPPES database
Registered at 25 LINCOLN CIR W, ANDOVER, MA 018102906 (Tel: 9788072611)
Registered at 25 LINCOLN CIR W, ANDOVER, MA 018102906
Recorded as ELLEN GAO
Nurse Practitioner (license number reported to NPPES: IL 209019665)
First registered as active Individual Practitioner in NPPES Database.
NPI Administrative Meta
Other Nurse Practitioners in Evanston
- Houri Papazian, APN-CNP
- Kurt Ortwig, APN-CNP
- Jintu Johnson, APN-CNP
- Jennifer Chamberlin, APN-CNP
- Kinga Chybowska, APN-CNP
- Patricia Otis, APN-CNP
Mailing Address
2650 Ridge Ave
Evanston, IL 602011700
Phone: 8474256400