ROBERT GRASS, MD
Adolescent Medicine (Internal Medicine) Physician in FOND DU LAC, Wisconsin. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.
What the federal data shows
ROBERT GRASS, MD filed 5,863 Medicare Part D claims in 2023 as a Adolescent Medicine (Internal Medicine) Physician in FOND DU LAC, Wisconsin, prescribing 90% generic.
- 6K
- Part D claims, 2023
- 90%
- generic prescribing
- Likely
- board-certified (heuristic)
Every figure on this page comes straight from federal CMS records (NPPES, Medicare Part D, MIPS, Open Payments) — no proprietary rating or editorial opinion is applied.
ROBERT GRASS, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023 — across all CMS prescribers nationally
5,863 Top 5% higher than 95% of 1,370,886 prescribers
Each bar is a band; taller bars hold more prescribers. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count, share, and where it sits relative to this entry.
Source CMS Medicare Part D Prescriber Public Use File · 2023
ROBERT GRASS, 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).
What does the federal data show about ROBERT GRASS, MD?
Quality data not reportedPrimary specialty
Medicare Part D claims
Specialty distribution in Wisconsin
How Adolescent Medicine (Internal Medicine) Physician compares to other specialties among Wisconsin providers
Adolescent Medicine (Internal Medicine) Physician share within Wisconsin
Adolescent Medicine (Internal Medicine) Physician is one of the more visible NUCC categories in Wisconsin
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 — Adolescent Medicine (Internal Medicine) Physician (ABMS / AOA reference)
- Est. board-certified rate
- 78%
- Adolescent Medicine (Internal Medicine) Physician ABMS/AOA estimate
Est. board-certified rate (Adolescent Medicine (Internal Medicine) Physician) — ABMS / AOA estimate
Verify credentials
- Verify via ABMS free public lookup
- Verify via AOA osteopathic boards
- Specialty volume Adolescent Medicine (Internal Medicine) Physician US NPIs
Specialty board-certified rate — Adolescent Medicine (Internal Medicine) 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).
ROBERT GRASS, MD appears in the CMS NPPES registry as a Adolescent Medicine (Internal Medicine) Physician provider holding MD credentials at 420 E DIVISION ST, FOND DU LAC, WI, 54935, with a listed phone of (920) 926-8615. NPI 1689665093 was issued on 11/03/2005. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what GRASS 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 5,863 prescription claims written by this provider, covering 358 Medicare beneficiaries and totaling roughly $473K in drug spend, split 10% brand-name and 90% generic by claim count, with an opioid prescribing rate of 1.8%. 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.
Adolescent Medicine (Internal Medicine) Physician is a narrow specialty nationwide, with 377 enrolled providers across 46 states and an average of 3,242 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 | 1689665093 |
|---|---|
| Specialty | Adolescent Medicine (Internal Medicine) Physician |
| Credentials | MD |
| Gender | Male |
| NPI Issued | 11/03/2005 |
Verify this provider's license
PlainDoctor pulls this profile from the CMS NPPES public registry. Confirm ROBERT GRASS, MD's current license status, disciplinary history, and board certifications with the Wisconsin Department of Safety and Professional Services in Wisconsin before relying on this page for a clinical or care decision.
How we sourced this profile
Hospital and facility affiliations
Facilities where ROBERT GRASS, 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).
Industry payments received (2024) — CMS Open Payments transparency data
The federal Physician Payments Sunshine Act (part of the Affordable Care Act) requires drug and medical-device manufacturers + group purchasing organizations to publicly report payments and other transfers of value to physicians and teaching hospitals. The data below covers 2024 for ROBERT GRASS, MD. Source: openpaymentsdata.cms.gov.
Total received
$17
Largest payer
E.R. Squibb & Sons, L.L.C.
Most common payment type
Education
Industry payments are not necessarily indicators of bias — they include research funding, consulting fees for evidence-based work, royalties for inventions, food at conferences, and similar items. The disclosure exists for transparency. Read our methodology for how we interpret this data.
Brand vs generic prescribing mix · Typical
10% brand-name claims vs 90% generic, on 5,863 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
- 12,772
- Total Day Supply
- 372,034
- Brand vs Generic
- 10% brand / 90% generic
- Brand Drug Cost
- $343K
- Generic Drug Cost
- $126K
- Opioid Claims
- 103 (1.8% rate)
- Antibiotic Claims
- 101
Patient Demographics
- Average Patient Age
- 73.3 years
- Avg HCC Risk Score
- 1.20
- Gender Split
- 37% female / 63% male
- Age Distribution
- <65: 34, 65-74: 172, 75-84: 116, 85+: 36
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What ROBERT GRASS, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Atorvastatin Calcium
Atorvastatin Calcium
303 claims
- Lisinopril
Lisinopril
198 claims
- Hydrochlorothiazide
Hydrochlorothiazide
196 claims
- Amlodipine Besylate
Amlodipine Besylate
188 claims
- Omeprazole
Omeprazole
169 claims
- Simvastatin
Simvastatin
168 claims
- Levothyroxine Sodium
Levothyroxine Sodium
167 claims
- Losartan Potassium
Losartan Potassium
151 claims
| Drug | Claims |
|---|---|
| Atorvastatin Calcium | 303 |
| Lisinopril | 198 |
| Hydrochlorothiazide | 196 |
| Amlodipine Besylate | 188 |
| Omeprazole | 169 |
| Simvastatin | 168 |
| Levothyroxine Sodium | 167 |
| Losartan Potassium | 151 |
| Pantoprazole Sodium | 125 |
| Sertraline Hcl | 116 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Adolescent Medicine (Internal Medicine) Physician Overview
How ROBERT GRASS, MD fits within the Adolescent Medicine (Internal Medicine) Physician landscape nationally.
ROBERT GRASS, MD's 5,863 claims are above the specialty average of 3,242.
Nearby Adolescent Medicine (Internal Medicine) Physician Providers in Wisconsin
Other clinicians with the same primary specialty enrolled in Wisconsin, drawn from the same CMS NPPES roster as GRASS.
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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