NPI registry status
Active
2026 NPPES data Physician Assistant NPI 1063468015 PA-C
Verify on CMS → Patrick Armstrong, PA-C
Physician Assistant in Chester, Montana.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 149,975 in Physician Assistant, 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
7K
Medicare Part D claims · 187 beneficiaries · Physician Assistant avg: 790
Generic prescribing
87%
generic claims · 12% 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
Patrick Armstrong, PA-C filed 6,873 Medicare Part D claims in 2023 as a Physician Assistant in Chester, Montana, prescribing 87% generic.
- 7K
- Part D claims, 2023
- 87%
- 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.
Patrick Armstrong, PA-C's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
6,873 Top 4% higher than 96% 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
What does the federal data show about Patrick Armstrong, PA-C?
Quality data not reportedPrimary specialty
Physician Assistant
Medicare Part D claims
6,873 9× vs specialty avg
Specialty distribution in Montana
How Physician Assistant compares to other specialties among Montana 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 Physician Assistant. 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).
Patrick Armstrong, PA-C appears in the CMS NPPES registry as a Physician Assistant provider holding PA-C credentials at 418 WEST MONROE, Chester, MT, 59522, with a listed phone of (406) 759-5181. NPI 1063468015 was issued on 05/25/2006.
Medicare Part D records for calendar year 2023 show 6,873 prescription claims written by this provider, covering 187 Medicare beneficiaries and totaling roughly $470K in drug spend, split 12% brand-name and 87% generic by claim count, with an opioid prescribing rate of 1.8%.
Physician Assistant is a high-volume specialty nationwide, with 149,975 enrolled providers across 56 states and an average of 790 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 | 1063468015 |
|---|---|
| Specialty | Physician Assistant |
| Credentials | PA-C |
| Gender | Male |
| NPI Issued | 05/25/2006 |
Brand vs generic prescribing mix · Typical
Patrick Armstrong, PA-C - brand share 12.0%
Physician Assistant average
12% brand-name claims vs 87% generic, on 6,873 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.
6,873
Total Claims
$470K
Total Drug Cost
187
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 8,864
- Total Day Supply
- 255,385
- Brand vs Generic
- 12% brand / 87% generic
- Brand Drug Cost
- $377K
- Generic Drug Cost
- $92K
- Opioid Claims
- 125 (1.8% rate)
- Antibiotic Claims
- 67
Patient Demographics
- Average Patient Age
- 77.8 years
- Avg HCC Risk Score
- 0.92
- Gender Split
- 55% female / 45% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Patrick Armstrong, PA-C prescribes most
Top Medicare Part D drugs by claim count, 2023
- Atorvastatin Calcium
Atorvastatin Calcium
320 claims
- Losartan Potassium
Losartan Potassium
284 claims
- Amlodipine Besylate
Amlodipine Besylate
281 claims
- Levothyroxine Sodium
Levothyroxine Sodium
273 claims
- Rosuvastatin Calcium
Rosuvastatin Calcium
257 claims
- Potassium Chloride
Potassium Chloride
213 claims
- Metoprolol Succinate
Metoprolol Succinate
207 claims
- Pantoprazole Sodium
Pantoprazole Sodium
177 claims
| Drug | Claims |
|---|---|
| Atorvastatin Calcium | 320 |
| Losartan Potassium | 284 |
| Amlodipine Besylate | 281 |
| Levothyroxine Sodium | 273 |
| Rosuvastatin Calcium | 257 |
| Potassium Chloride | 213 |
| Metoprolol Succinate | 207 |
| Pantoprazole Sodium | 177 |
| Furosemide | 174 |
| Tamsulosin Hcl | 158 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Physician Assistant Overview
How Patrick Armstrong, PA-C fits within the Physician Assistant landscape nationally.
149,975
Physician Assistant Providers in US
56
States with Physician Assistant
790
Avg Claims per Provider
Patrick Armstrong, PA-C's 6,873 claims are above the specialty average of 790.
Nearby Physician Assistant Providers in Montana
Other clinicians with the same primary specialty enrolled in Montana, drawn from the same CMS NPPES roster as Armstrong.
Dr. Patrick Alduenda
PA-C
Helena, MT
Dr. Jesse Alfiero
PA-C
Ronan, MT
Dr. Robert Alfiero
PA-C
Ronan, MT
Dr. Sarah Alke
PA-C
Bozeman, MT
Dr. Janel Allison-Shamblin
PA-C
Bozeman, MT
Compare Physician Assistant nationally: see state-by-state distribution →
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 Montana medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Physician Assistant 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.
Healthcare Guides
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Medical Specialties Explained
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Understanding Medicare Claims Data
What prescribing data reveals about a provider
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How insurance networks affect your costs
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Explore Montana
Frequently Asked Questions
What is Patrick Armstrong, PA-C's specialty? ▼
Patrick Armstrong, PA-C specializes in Physician Assistant and practices in Chester, Montana. Credentials: PA-C.
How much does Patrick Armstrong, PA-C prescribe under Medicare Part D? ▼
In 2023, Patrick Armstrong, PA-C wrote 6,873 Medicare Part D claims totaling $470K in drug costs for 187 beneficiaries.
Where is Patrick Armstrong, PA-C located? ▼
Patrick Armstrong, PA-C is located at 418 WEST MONROE, Chester, MT, 59522. Phone: (406) 759-5181.
What is Patrick Armstrong, PA-C's NPI number? ▼
Patrick Armstrong, PA-C's National Provider Identifier (NPI) is 1063468015, issued on 05/25/2006.
Does Patrick Armstrong, PA-C prescribe more brand-name or generic drugs? ▼
Patrick Armstrong, PA-C's prescribing is 12% brand-name and 87% generic drugs by claim count, with $377K in brand drug costs.
Does Patrick Armstrong, PA-C prescribe opioids? ▼
Yes, Patrick Armstrong, PA-C had 125 opioid claims in 2023 with an opioid prescribing rate of 1.8%.
How many Physician Assistant providers are there in the US? ▼
There are 149,975 Physician Assistant providers across 56 states in the US. The average Physician Assistant provider writes 790 Medicare Part D claims per year.
What drugs does Patrick Armstrong, PA-C prescribe most often? ▼
Based on 2023 Medicare Part D data, Patrick Armstrong, PA-C's most frequently prescribed drugs include Atorvastatin Calcium, Losartan Potassium, Amlodipine Besylate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Patrick Armstrong, PA-C accept Medicare? ▼
Patrick Armstrong, PA-C appears in CMS Medicare data with 6,873 Part D claims and 187 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Patrick Armstrong, PA-C's credentials? ▼
Patrick Armstrong, PA-C's NPI is 1063468015 with credentials PA-C. 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.