Dr. John Allan Walker , MD
Internal Medicine • Modesto, CA
820 Scenic Dr
Modesto, CA 953506131
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 October 16, 2006; this date does not establish years in practice.
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Published CMS data list 44 Original Medicare Part B services in 2017.
Source: CMS, Medicare Physician & Other Practitioners – by Provider and Service, 2017. Published rows only; this is not a quality measure.
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Published Part B service records, 2017:
- 87491 — Detection test by nucleic acid for chlamydia trachomatis, amplified probe technique: 22 service units.
- 87591 — Detection test by nucleic acid for neisseria gonorrhoeae (gonorrhoeae bacteria), amplified probe technique: 22 service units.
Source: CMS, Medicare Physician & Other Practitioners – by Provider and Service, 2017. Units differ by code; these are not visits or a measure of quality.
CPT® only copyright 2016 American Medical Association. All rights reserved. Service names are shortened from CPT Consumer Friendly Descriptors (CMS data, 2017). CPT notice
See the full table · Guide: How to read Medicare Part B data
Practice Location & Contact Primary Location
820 Scenic Dr
Modesto, CA 953506131
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.
Medicare patients
31 people with Original Medicare in 2017
It gives a sense of how many people with Medicare this clinician treated that year.
Source: CMS, Medicare Physician & Other Practitioners – by Provider, 2017.
Medicare-allowed amount
About $2,076 in 2017
The total amount Medicare approved for these services in 2017. 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, 2017.
Paid by Medicare
About $2,076 in 2017
The part of the Medicare-allowed amount that Medicare itself paid in 2017, 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, 2017.
Industry payments (Open Payments)
No Open Payments records are listed for this clinician for 2019–2025.
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, CMS release of October 2, 2026; 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, CMS release of October 2, 2026.
Compared with the same specialty in Modesto and California
Billing and prescribing volume is not a quality rating.
Medicare Part B
Comparisons use 2024 data. The latest CMS data for Dr. Walker are from 2017.
134 active clinicians are listed under Internal Medicine with a practice address in Modesto, CA (17,897 in California).
Addresses are self-reported to NPPES and may be out of date.
Telehealth indicator in Modesto
24.6% of these 134 clinicians have the CMS telehealth indicator.
73.1% of these 134 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
CMS data for Medicare Part B services are available for 2017 only.
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Medicare-allowed amount
CMS data for Medicare-allowed amount are available for 2017 only.
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Paid by Medicare
CMS data for Medicare payment amount are available for 2017 only.
Sources: CMS Medicare Physician & Other Practitioners (2017), CMS Doctors and Clinicians, CMS release of October 2, 2026, CMS NPPES NPI Registry. Specialty names follow the NUCC Health Care Provider Taxonomy.
Text: T-MedInfo · Report an error.
Performed Procedures & Service Volume
CPT® is a registered trademark of the American Medical Association. CPT codes, descriptions and other data only are copyright 2016 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; 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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87491
Detection test by nucleic acid for chlamydia trachomatis, amplified probe technique
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22 | 22 | $82.00 | $47.18 |
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87591
Detection test by nucleic acid for neisseria gonorrhoeae (gonorrhoeae bacteria), amplified probe technique
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22 | 22 | $82.00 | $47.18 |
Source: CMS Part B by Provider and Service, 2017; services under 11 beneficiaries omitted by CMS. Privacy limits
Submitted charges are billed amounts, not a price quote for your visit.
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.
Career & Practice History
NPI enumerated October 16, 2006.
No changes to the name, practice address, taxonomy or NPI status in this record have been observed in the monthly NPPES data files from January 2017 to November 2026.
NPI Administrative Meta
Other Internal Medicine Providers in Modesto
- Dr. Mahyar Mahdavi Doraji, MD
- Dr. Khin Win, MD
- Dr. Weizheng Jiang, MD
- Dr. Rajwinder Bahia, MD
- Dr. Onkar Mudhar, MD
- Dr. Ripudaman Munjal, MD
Mailing Address
820 Scenic Dr
Modesto, CA 953506131