NPI registry status
Active
2026 NPPES data Geriatric Medicine (Internal Medicine) Physician NPI 1245229897 MD
Verify on CMS → Catherine Gruer, MD
Geriatric Medicine (Internal Medicine) Physician in Allentown, Pennsylvania.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 4,161 in Geriatric Medicine (Internal Medicine) Physician, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
Prescribing volume
3K
Medicare Part D claims · 114 beneficiaries · Geriatric Medicine (Internal Medicine) Physician avg: 4K
Generic prescribing
82%
generic claims · 18% brand-name · higher generic rates reduce patient out-of-pocket costs
Source: CMS Medicare Part D Prescriber Public Use File, 2023
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Catherine Gruer, MD filed 3,054 Medicare Part D claims in 2023 as a Geriatric Medicine (Internal Medicine) Physician in Allentown, Pennsylvania, prescribing 82% generic.
- 3K
- Part D claims, 2023
- 82%
- generic prescribing
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.
Catherine Gruer, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
3,054 Top 11% higher than 89% 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
◑
Board-eligible specialty (heuristic, not verified)
Catherine Gruer, MD practices in an ABMS-board-eligible specialty but we don't have enough CMS-participation signals to confirm active board-certified status. Consult CertificationMatters.org (the official ABMS public lookup).
What does the federal data show about Catherine Gruer, MD?
Quality data not reportedPrimary specialty
Geriatric Medicine (Internal Medicine) Physician
Medicare Part D claims
3,054 31% vs specialty avg
Specialty distribution in Pennsylvania
How Geriatric Medicine (Internal Medicine) Physician compares to other specialties among Pennsylvania providers
Board certification
Not published by CMS
CMS does not publish a per-provider board-certification field in NPPES. PlainDoctor does not have a reliable per-specialty certification rate to show for Geriatric Medicine (Internal Medicine) Physician. Verify directly:
How MIPS and board certification work
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).
Catherine Gruer, MD appears in the CMS NPPES registry as a Geriatric Medicine (Internal Medicine) Physician provider holding MD credentials at 17TH & CHEW STREET, Allentown, PA, 18105, with a listed phone of (610) 969-3390. NPI 1245229897 was issued on 10/17/2005.
Medicare Part D records for calendar year 2023 show 3,054 prescription claims written by this provider, covering 114 Medicare beneficiaries and totaling roughly $180K in drug spend, split 18% brand-name and 82% generic by claim count.
Geriatric Medicine (Internal Medicine) Physician is a narrow specialty nationwide, with 4,161 enrolled providers across 52 states and an average of 4,450 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 | 1245229897 |
|---|---|
| Specialty | Geriatric Medicine (Internal Medicine) Physician |
| Credentials | MD |
| Gender | Female |
| NPI Issued | 10/17/2005 |
License & disciplinary context - Pennsylvania PA-BOM 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 ~45K Pennsylvania medical licensees in 2023 - they are NOT specific to Catherine Gruer, MD. To verify Catherine Gruer, MD's current license status, search the PA-BOM public license lookup directly, or check the Federation of State Medical Boards (FSMB) verification service.
133
Total board actions, Pennsylvania 2023
Across 129 cases
2.96
Actions per 1,000 licensees
Pennsylvania statewide rate
probation
Most common action type
48 cases
PA-BOM 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 Pennsylvania disciplinary trends page. Cross-checked against FSMB U.S. Medical Regulatory Trends.
Brand vs generic prescribing mix · Typical
Catherine Gruer, MD - brand share 18.0%
Geriatric Medicine (Internal Medicine) Physician average
18% brand-name claims vs 82% generic, on 3,054 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.
3,054
Total Claims
$180K
Total Drug Cost
114
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 3,055
- Total Day Supply
- 70,953
- Brand vs Generic
- 18% brand / 82% generic
- Brand Drug Cost
- $120K
- Generic Drug Cost
- $60K
- Antibiotic Claims
- 11
Patient Demographics
- Average Patient Age
- 80.8 years
- Avg HCC Risk Score
- 2.27
- Gender Split
- 54% female / 46% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Catherine Gruer, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Atorvastatin Calcium
Atorvastatin Calcium
152 claims
- Pantoprazole Sodium
Pantoprazole Sodium
133 claims
- Levothyroxine Sodium
Levothyroxine Sodium
124 claims
- Gabapentin
Gabapentin
119 claims
- Losartan Potassium
Losartan Potassium
115 claims
- Insulin Lispro Kwi…
Insulin Lispro Kwikpen U-100
109 claims
- Amlodipine Besylate
Amlodipine Besylate
100 claims
- Lisinopril
Lisinopril
85 claims
| Drug | Claims |
|---|---|
| Atorvastatin Calcium | 152 |
| Pantoprazole Sodium | 133 |
| Levothyroxine Sodium | 124 |
| Gabapentin | 119 |
| Losartan Potassium | 115 |
| Insulin Lispro Kwikpen U-100 Insulin Lispro | 109 |
| Amlodipine Besylate | 100 |
| Lisinopril | 85 |
| Metformin Hcl | 85 |
| Metoprolol Succinate | 85 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
More Geriatric Medicine (Internal Medicine) Physician in PA →
All providers in Pennsylvania →
Compare specialties →
Geriatric Medicine (Internal Medicine) Physician Overview
How Catherine Gruer, MD fits within the Geriatric Medicine (Internal Medicine) Physician landscape nationally.
4,161
Geriatric Medicine (Internal Medicine) Physician Providers in US
52
States with Geriatric Medicine (Internal Medicine) Physician
4,450
Avg Claims per Provider
Catherine Gruer, MD's 3,054 claims are below the specialty average of 4,450.
Nearby Geriatric Medicine (Internal Medicine) Physician Providers in Pennsylvania
Other clinicians with the same primary specialty enrolled in Pennsylvania, drawn from the same CMS NPPES roster as Gruer.
Before you book an appointment
Use this federal record as your verification checklist, not as a recommendation.
- Confirm the NPI record is current in the official CMS registry, providers update their own NPPES details, and moves can lag. Verify this NPI
- Check the active license and any disciplinary history with the Pennsylvania medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Geriatric Medicine (Internal Medicine) Physician peer on Medicare volume and prescribing patterns. Compare providers
Medicare Part D and MIPS figures describe practice patterns in federal programs only, they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.
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Frequently Asked Questions
What is Catherine Gruer, MD's specialty? ▼
Catherine Gruer, MD specializes in Geriatric Medicine (Internal Medicine) Physician and practices in Allentown, Pennsylvania. Credentials: MD.
How much does Catherine Gruer, MD prescribe under Medicare Part D? ▼
In 2023, Catherine Gruer, MD wrote 3,054 Medicare Part D claims totaling $180K in drug costs for 114 beneficiaries.
Where is Catherine Gruer, MD located? ▼
Catherine Gruer, MD is located at 17TH & CHEW STREET, Allentown, PA, 18105. Phone: (610) 969-3390.
What is Catherine Gruer, MD's NPI number? ▼
Catherine Gruer, MD's National Provider Identifier (NPI) is 1245229897, issued on 10/17/2005.
Does Catherine Gruer, MD prescribe more brand-name or generic drugs? ▼
Catherine Gruer, MD's prescribing is 18% brand-name and 82% generic drugs by claim count, with $120K in brand drug costs.
How many Geriatric Medicine (Internal Medicine) Physician providers are there in the US? ▼
There are 4,161 Geriatric Medicine (Internal Medicine) Physician providers across 52 states in the US. The average Geriatric Medicine (Internal Medicine) Physician provider writes 4,450 Medicare Part D claims per year.
What drugs does Catherine Gruer, MD prescribe most often? ▼
Based on 2023 Medicare Part D data, Catherine Gruer, MD's most frequently prescribed drugs include Atorvastatin Calcium, Pantoprazole Sodium, Levothyroxine Sodium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Catherine Gruer, MD accept Medicare? ▼
Catherine Gruer, MD appears in CMS Medicare data with 3,054 Part D claims and 114 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Catherine Gruer, MD's credentials? ▼
Catherine Gruer, MD's NPI is 1245229897 with credentials MD. You can verify this through the NPPES NPI Registry, check state medical board records, and confirm board certification through the ABMS or AOA.
Data Sources
View source datasets and methodology notes
- 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
Compiled from official public sources by the PlainDoctor editorial team.