Dr. John Frederick Shield , MD
Internal Medicine • Sonora, CA
690 Guzzi Ln, Suite A
Sonora, CA 953705289
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 January 25, 2006; this date does not establish years in practice.
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Published CMS data list 4,061 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:
- 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: 1,220 service units.
- 99214 — Established patient outpatient office visit: 1,036 service units.
- 99213 — Established patient outpatient office visit: 456 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 11 records in the table · Guide: How to read Medicare Part B data
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Published CMS data list 8,815 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:
- Amlodipine Besylate — 583 prescription fills, including refills.
- Losartan Potassium — 456 prescription fills, including refills.
- Valsartan — 455 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 114 records in the table · Guide: How to read Medicare Part D prescriber data
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More Medicare Part B services than 80% of clinicians listed under Internal Medicine in Sonora, CA (2024, 11 clinicians with data). Median for this group: 1,985. Middle half: 940 to 3,689.
More Medicare Part B services than 90% of clinicians listed under Internal Medicine in California (2024, 8,010 clinicians with data). Median for this group: 547. Middle half: 197 to 1,237.
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 2,578 in 2020 to 4,061 in 2024.
Source: CMS, Medicare Physician & Other Practitioners – by Provider and Service, 2020–2024.
Practice Location & Contact Primary Location
690 Guzzi Ln
Suite A
Sonora, CA 953705289
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 3 distinct group names: Sonora Community Hospital; Union Associated Physicians Clinic, Llc; Valley Professionals Community Health Center Inc. 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
1980
What Public CMS Data Show
Internal Medicine: NPPES taxonomy is a reported classification, not proof of board certification.
Medicare patients
910 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 $173,701 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 $120,095 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
20,317 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
$870,377 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)
No Open Payments records are listed for this clinician for 2019–2025.
Years since graduation
46 years (graduated 1980)
CMS Doctors and Clinicians data list 1980 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, “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)
Dr. Shield 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. Shield 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 Sonora and California
Billing and prescribing volume is not a quality rating.
Medicare Part B services
More Medicare Part B services than 80% of clinicians listed under Internal Medicine in Sonora, CA (2024, 11 clinicians with data). Median for this group: 1,985. Middle half: 940 to 3,689.
More Medicare Part B services than 90% of clinicians listed under Internal Medicine in California (2024, 8,010 clinicians with data). Median for this group: 547. Middle half: 197 to 1,237.
Medicare-allowed amount
A lower Medicare-allowed amount than 60% of clinicians listed under Internal Medicine in Sonora, CA (2024, 11 clinicians with data). Median for this group: $198,581. Middle half: $134,956 to $246,786.
A higher Medicare-allowed amount than 80% of clinicians listed under Internal Medicine in California (2024, 8,010 clinicians with data). Median for this group: $57,305. Middle half: $20,387 to $125,671.
Paid by Medicare
A lower Medicare payment amount than 60% of clinicians listed under Internal Medicine in Sonora, CA (2024, 11 clinicians with data). Median for this group: $157,496. Middle half: $104,702 to $195,917.
A higher Medicare payment amount than 80% of clinicians listed under Internal Medicine in California (2024, 8,010 clinicians with data). Median for this group: $43,389. Middle half: $14,879 to $95,775.
Medicare Part D prescriptions
More Part D prescriptions than 90% of clinicians listed under Internal Medicine in Sonora, CA (2024, 12 clinicians with data). Median for this group: 2,437. Middle half: 190 to 8,097.
More Part D prescriptions than 90% of clinicians listed under Internal Medicine in California (2024, 10,854 clinicians with data). Median for this group: 1,235. Middle half: 145 to 4,223.
Part D drug cost
A higher Part D drug cost than 90% of clinicians listed under Internal Medicine in Sonora, CA (2024, 12 clinicians with data). Median for this group: $176,801. Middle half: $6,964 to $615,941.
A higher Part D drug cost than 90% of clinicians listed under Internal Medicine in California (2024, 10,854 clinicians with data). Median for this group: $86,796. Middle half: $7,321 to $305,686.
17 active clinicians are listed under Internal Medicine with a practice address in Sonora, CA (17,888 in California).
Addresses are self-reported to NPPES and may be out of date.
Telehealth indicator in Sonora
17.6% of these 17 clinicians have the CMS telehealth indicator.
64.7% of these 17 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 58% from 2,578 in 2020 to 4,061 in 2024.
- 2020: 2,578
- 2021: 3,120
- 2022: 2,967
- 2023: 2,601
- 2024: 4,061
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Medicare-allowed amount
Medicare-allowed amount increased 24% from $139,892 in 2020 to $173,701 in 2024.
- 2020: $139,892
- 2021: $192,917
- 2022: $176,676
- 2023: $160,858
- 2024: $173,701
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Paid by Medicare
Paid by Medicare increased 27% from $94,398 in 2020 to $120,095 in 2024.
- 2020: $94,398
- 2021: $131,851
- 2022: $117,669
- 2023: $108,848
- 2024: $120,095
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Medicare Part D prescriptions
Medicare Part D prescriptions stayed about the same: 9,657 in 2020 and 8,815 in 2024.
- 2020: 9,657
- 2021: 9,812
- 2022: 9,186
- 2023: 8,852
- 2024: 8,815
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30-day fills
30-day fills stayed about the same: 21,617 in 2020 and 20,317 in 2024.
- 2020: 21,617
- 2021: 21,407
- 2022: 20,384
- 2023: 20,090
- 2024: 20,317
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Part D drug cost
Part D drug cost increased 24% from $700,419 in 2020 to $870,377 in 2024.
- 2020: $700,419
- 2021: $833,550
- 2022: $788,818
- 2023: $841,996
- 2024: $870,377
Sources: CMS Medicare Physician & Other Practitioners (2024), CMS Medicare Part D Prescribers (2024), CMS Doctors and Clinicians, 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 2016–2023 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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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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1,220 | 507 | $42.17 | $16.36 |
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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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1,036 | 440 | $198.00 | $96.12 |
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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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456 | 288 | $134.00 | $65.14 |
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94729
Test to examine how well the lungs exchange gases
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387 | 386 | $22.00 | $8.61 |
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94060
Test to measure expiratory airflow and volume changes before and after medication administration
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376 | 375 | $26.00 | $9.96 |
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94726
Test to determine lung volumes using sensors
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375 | 374 | $30.00 | $11.63 |
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93010
Routine electrocardiogram (ecg) using at least 12 leads with interpretation and report only
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78 | 72 | $33.85 | $7.99 |
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99215
Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more
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73 | 62 | $292.00 | $142.26 |
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99212
Established patient office or other outpatient visit with straightforward medical decision making, if using time, 10 minutes or more
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28 | 23 | $72.00 | $34.79 |
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17000
Destruction of precancer skin growth, 1 growth
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16 | 12 | $158.00 | $56.84 |
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94010
Test to measure expiratory airflow and volume
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16 | 16 | $21.00 | $7.99 |
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 |
|---|---|---|---|---|---|
| Amlodipine Besylate | Amlodipine Besylate | 583 | 43,492 | $3,747.73 | 136 |
| Losartan Potassium | Losartan Potassium | 456 | 36,775 | $4,776.78 | 118 |
| Valsartan | Valsartan | 455 | 34,583 | $17,142.37 | 114 |
| Atorvastatin Calcium | Atorvastatin Calcium | 436 | 35,922 | $4,558.03 | 114 |
| Levothyroxine Sodium | Levothyroxine Sodium | 355 | 25,295 | $3,859.72 | 79 |
| Omeprazole | Omeprazole | 321 | 22,547 | $3,971.91 | 81 |
| Rosuvastatin Calcium | Rosuvastatin Calcium | 307 | 24,609 | $5,474.90 | 86 |
| Metoprolol Succinate | Metoprolol Succinate | 252 | 18,251 | $4,222.24 | 63 |
| Simvastatin | Simvastatin | 236 | 18,485 | $2,094.59 | 58 |
| Lisinopril | Lisinopril | 231 | 18,471 | $1,806.10 | 58 |
| Hydrochlorothiazide | Hydrochlorothiazide | 226 | 15,570 | $1,103.08 | 54 |
| Metformin Hcl Er | Metformin Hcl | 178 | 14,670 | $1,848.90 | 54 |
| Pantoprazole Sodium | Pantoprazole Sodium | 155 | 10,770 | $2,357.82 | 35 |
| Jardiance | Empagliflozin | 151 | 9,030 | $174,781.10 | 33 |
| Furosemide | Furosemide | 146 | 10,407 | $738.36 | 40 |
| Doxazosin Mesylate | Doxazosin Mesylate | 135 | 10,582 | $2,392.42 | 37 |
| Tamsulosin Hcl | Tamsulosin Hcl | 130 | 8,213 | $1,628.59 | 35 |
| Pioglitazone Hcl | Pioglitazone Hcl | 126 | 7,680 | $1,061.95 | 28 |
| Diltiazem 24hr Er (Cd) | Diltiazem Hcl | 124 | 7,320 | $2,808.14 | 27 |
| Gabapentin | Gabapentin | 122 | 8,730 | $4,016.28 | 35 |
| Alendronate Sodium | Alendronate Sodium | 120 | 6,860 | $943.24 | 26 |
| Potassium Chloride | Potassium Chloride | 112 | 7,590 | $2,917.82 | 34 |
| Ozempic | Semaglutide | 108 | 4,278 | $135,282.61 | 17 |
| Allopurinol | Allopurinol | 104 | 8,100 | $945.19 | 27 |
| Famotidine | Famotidine | 102 | 8,434 | $1,155.93 | 34 |
(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: 2024-06-24NUCC 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
I20080625000410
CA
7911078563
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
Union Associated Physicians Clinic, Llc
1530 N 7th St, Terre Haute, IN 478071057
Phone: 8122341344
Sonora Community Hospital
18661 Hwy 120, Groveland, CA 953219432
Phone: 2099627121
Valley Professionals Community Health Center Inc
1530 N 7th St, Terre Haute, IN 478071061
Phone: 8122387631
Valley Professionals Community Health Center Inc
777 S Main St, Clinton, IN 478422493
Phone: 7658281003
Clinicians Sharing This Practice Address or Phone
Clinicians sharing this NPPES address, phone or fax; a shared contact does not mean they work together.
Nurse Practitioner - Primary Care
Nurse Practitioner
Career & Practice History Timeline
Changes recorded in monthly NPPES data files: addresses, names, credentials, specialties and NPI status
Registered at 690 GUZZI LN STE A, SONORA, CA 953705292 (Tel: 2095365070)
Internal Medicine (license number reported to NPPES: CA G45205)
NPI status registered as active in NPPES database
Registered at 690 GUZZI LN, SUITE A, SONORA, CA 953705289 (Tel: 2095365070)
Registered at 16280 STINE CT, SONORA, CA 953708124 (Tel: 2095334918)
Recorded as JOHN SHIELD, MD
Internal Medicine (license number reported to NPPES: CA G45205)
First registered as active Individual Practitioner in NPPES Database.
NPI Administrative Meta
Other Internal Medicine Providers in Sonora
- Dr. Johnson Wong, MD
- Dr. Jason Jeffery, MD
- Dr. Kyi Kyi Win, MD
- Dr. Maureen Regan, MD
- Dr. Zachary Nichols, DO
- Dr. Kevin Gandhi, DO
More public profiles in California
Directory navigation, in NPI number order.
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- Deborah Kim, MD Ophthalmology - Glaucoma Specialist · Lancaster
Mailing Address
690 Guzzi Ln Ste A
Sonora, CA 953705292
Phone: 2095365070