JOHN MAYNARD, MD
Nephrology Physician in ROCKFORD, Illinois. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.
What stands out: JOHN MAYNARD, MD filed 1,199 Medicare Part D claims in 2023 across ROCKFORD, Illinois. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.
JOHN MAYNARD, MD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation — signals consistent with board-certified status. For verified board certification, see CertificationMatters.org (the official ABMS public lookup).
JOHN MAYNARD, MD at a glance
Quality data not reportedPrimary specialty
Medicare Part D claims
Specialty distribution in Illinois
How Nephrology Physician compares to other specialties among Illinois providers
Nephrology Physician share within Illinois
Nephrology Physician is one of the more visible NUCC categories in Illinois
Each bar reflects the share of in-state providers whose primary NUCC taxonomy matches the specialty. Long tail of ~690 NUCC codes folded into "Other" to keep the comparison legible.
Specialty board-certification context
Estimated specialty board-certified rate — Nephrology Physician (ABMS / AOA reference)
- Est. board-certified rate
- 78%
- Nephrology Physician ABMS/AOA estimate
Est. board-certified rate (Nephrology Physician) — ABMS / AOA estimate
Verify credentials
- Verify via ABMS free public lookup
- Verify via AOA osteopathic boards
- Specialty volume Nephrology Physician US NPIs
Specialty board-certified rate — Nephrology Physician estimate
Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus Maintenance of Certification cycles. CMS does not publish a per-provider board-certification field; the figure shown is the specialty-level estimated rate from ABMS / AOA reference data.
The Merit-based Incentive Payment System (MIPS) scores providers 0–100 across four performance categories: Quality, Cost, Promoting Interoperability, and Improvement Activities, weighted under 42 CFR §414.1380. Reporting is voluntary for many small practices, so absence of a MIPS score is not a quality signal.
Board certification through an ABMS or AOA member board signals voluntary post-licensure examination plus continuous Maintenance of Certification cycles. Verify any individual provider's status through certificationmatters.org (ABMS) or osteopathic.org (AOA).
JOHN MAYNARD, MD is a Nephrology Physician provider practicing in ROCKFORD, Illinois, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: MD. NPI: 1730180878. This profile includes practice location, specialty classification, and organizational affiliations from the CMS provider registry. Provider information is self-reported to CMS and updated monthly.
JOHN MAYNARD, MD appears in the CMS NPPES registry as a Nephrology Physician provider holding MD credentials at 612 ROXBURY RD, ROCKFORD, IL, 61107, with a listed phone of (815) 227-8300. NPI 1730180878 was issued on 08/10/2005. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what MAYNARD most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.
Medicare Part D records for calendar year 2023 show 1,199 prescription claims written by this provider, covering 256 Medicare beneficiaries and totaling roughly $86K in drug spend, split 6% brand-name and 94% generic by claim count. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.
Nephrology Physician is a mid-sized specialty nationwide, with 10,534 enrolled providers across 55 states and an average of 1,454 Part D claims per prescriber, so the context for interpreting these metrics differs meaningfully from a primary-care baseline. Important: PlainDoctor is a directory of publicly available government data, not medical advice, a malpractice database, or a quality rating. Inclusion here does not imply a recommendation, and absence of complaints or sanctions on this page does not mean none exist — always verify credentials through the NPPES NPI Registry, your state medical board, and the ABMS or AOA before making healthcare decisions.
Practice Address
Provider Details
| NPI | 1730180878 |
|---|---|
| Specialty | Nephrology Physician |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 08/10/2005 |
Verify this provider's license
PlainDoctor pulls this profile from the CMS NPPES public registry. Confirm JOHN MAYNARD, MD's current license status, disciplinary history, and board certifications with the Illinois Department of Financial and Professional Regulation in Illinois before relying on this page for a clinical or care decision.
How we sourced this profile
Hospital and facility affiliations
Facilities where JOHN MAYNARD, MD bills Medicare from. Star ratings (1-5) are CMS Hospital Compare's "Hospital overall rating" — a composite of mortality, readmission, patient experience, safety, timely care, and efficient use of medical imaging measures. Source: CMS Care Compare.
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
License & disciplinary context — Illinois IDFPR 2023 annual report
Aggregate state board data only — NOT a determination of any individual provider's status. The figures below describe statewide disciplinary activity across all ~42K Illinois medical licensees in 2023 — they are NOT specific to JOHN MAYNARD, MD. To verify JOHN MAYNARD, MD's current license status, search the IDFPR public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
IDFPR publishes annual disciplinary statistics as part of public-record reporting under each state's Administrative Procedure Act. See the full breakdown by action type and year on the Illinois disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.
Brand vs generic prescribing mix · Generic-heavy
6% brand-name claims vs 94% generic, on 1,199 2023 Medicare Part D claims.
The federal Medicare Part D Generic Dispensing Rate national benchmark sits near 90% generic / 10% brand for primary-care prescribers, per CMS Office of the Actuary 2024 estimates. Higher brand share is common in specialty prescribing where generic equivalents are not available.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
Prescribing Breakdown
- 30-Day Fills
- 3,055
- Total Day Supply
- 90,528
- Brand vs Generic
- 6% brand / 94% generic
- Brand Drug Cost
- $41K
- Generic Drug Cost
- $45K
- Antibiotic Claims
- 18
Patient Demographics
- Average Patient Age
- 71.4 years
- Avg HCC Risk Score
- 3.79
- Gender Split
- 52% female / 48% male
- Age Distribution
- <65: 54, 65-74: 85, 75-84: 91, 85+: 26
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
| Drug | Claims |
|---|---|
| Lisinopril | 146 |
| Terazosin Hcl | 139 |
| Calcitriol | 130 |
| Furosemide | 125 |
| Losartan Potassium | 87 |
| Vitamin D2 Ergocalciferol (Vitamin D2) | 60 |
| Metoprolol Succinate | 59 |
| Atenolol | 57 |
| Sevelamer Carbonate | 44 |
| Farxiga Dapagliflozin Propanediol | 42 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Nephrology Physician Overview
How JOHN MAYNARD, MD fits within the Nephrology Physician landscape nationally.
JOHN MAYNARD, MD's 1,199 claims are below the specialty average of 1,454.
Nearby Nephrology Physician Providers in Illinois
Other clinicians with the same primary specialty enrolled in Illinois, drawn from the same CMS NPPES roster as MAYNARD.
Compare Nephrology Physician nationally: see state-by-state distribution →
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Frequently Asked Questions
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Data Sources
- Provider Directory
- CMS National Plan and Provider Enumeration System (NPPES), download.cms.gov/nppes, updated monthly. Contains NPI, specialty, credentials, and practice location.
- Specialty Classification
- NUCC Health Care Provider Taxonomy (nucc.org), the industry standard for classifying provider specialties in Medicare and Medicaid billing.
- Prescribing Data
- CMS Medicare Part D Prescriber Public Use File (2023). Includes claims, drug costs, beneficiaries, and opioid prescribing rates.
- Limitations
- Provider data is self-reported to CMS. Prescribing data reflects Medicare Part D only and does not include commercial insurance, Medicaid, or cash prescriptions. Claims below 11 beneficiaries are suppressed by CMS for privacy.
See our complete data methodology for details on how we collect and process government data.
Data as of April 2026 (NPPES) / 2023 (Medicare Part D). Source: Centers for Medicare & Medicaid Services (CMS).
Disclaimer: Data from CMS NPPES and Medicare Part D. PlainDoctor does not rate or rank providers. Provider information is self-reported and may not be current. Always verify information directly with the provider. About · Methodology