NPI registry status
Active
2026 NPPES data Physician Assistant NPI 1639290414 PA
Verify on CMS → Joanna Armstrong, PA
Physician Assistant in Indianapolis, Indiana.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 150,974 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
949
Medicare Part D claims · 98 beneficiaries · Physician Assistant avg: 790
Generic prescribing
84%
generic claims · 16% 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
Joanna Armstrong, PA filed 949 Medicare Part D claims in 2023 as a Physician Assistant in Indianapolis, Indiana, prescribing 84% generic.
- 949
- Part D claims, 2023
- 84%
- 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.
Joanna Armstrong, PA's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
949 Top 25% higher than 75% 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 Joanna Armstrong, PA?
Quality data not reportedPrimary specialty
Physician Assistant
Medicare Part D claims
949 20% vs specialty avg
Specialty distribution in Indiana
How Physician Assistant compares to other specialties among Indiana 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).
Joanna Armstrong, PA appears in the CMS NPPES registry as a Physician Assistant provider holding PA credentials at 1800 N CAPITOL AVE, Indianapolis, IN, 46202, with a listed phone of (317) 962-2894. NPI 1639290414 was issued on 04/02/2007.
Medicare Part D records for calendar year 2023 show 949 prescription claims written by this provider, covering 98 Medicare beneficiaries and totaling roughly $71K in drug spend, split 16% brand-name and 84% generic by claim count, with an opioid prescribing rate of 4.8%.
Physician Assistant is a high-volume specialty nationwide, with 150,974 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 | 1639290414 |
|---|---|
| Specialty | Physician Assistant |
| Credentials | PA |
| Gender | Female |
| NPI Issued | 04/02/2007 |
Hospital and facility affiliations
Facilities where Joanna Armstrong, PA 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.
Directed Rehabilitation Services
Indianapolis, IN
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
Brand vs generic prescribing mix · Typical
Joanna Armstrong, PA - brand share 16.0%
Physician Assistant average
16% brand-name claims vs 84% generic, on 949 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.
949
Total Claims
$71K
Total Drug Cost
98
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 952
- Total Day Supply
- 23,036
- Brand vs Generic
- 16% brand / 84% generic
- Brand Drug Cost
- $52K
- Generic Drug Cost
- $20K
- Opioid Claims
- 46 (4.8% rate)
Patient Demographics
- Average Patient Age
- 77.5 years
- Avg HCC Risk Score
- 1.80
- Gender Split
- 67% female / 33% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Joanna Armstrong, PA prescribes most
Top Medicare Part D drugs by claim count, 2023
- Levothyroxine Sodium
Levothyroxine Sodium
72 claims
- Gabapentin
Gabapentin
51 claims
- Donepezil Hcl
Donepezil Hcl
45 claims
- Simvastatin
Simvastatin
39 claims
- Lisinopril
Lisinopril
35 claims
- Sertraline Hcl
Sertraline Hcl
30 claims
- Atorvastatin Calcium 28
Atorvastatin Calcium
28 claims
- Omeprazole 27
Omeprazole
27 claims
| Drug | Claims |
|---|---|
| Levothyroxine Sodium | 72 |
| Gabapentin | 51 |
| Donepezil Hcl | 45 |
| Simvastatin | 39 |
| Lisinopril | 35 |
| Sertraline Hcl | 30 |
| Atorvastatin Calcium | 28 |
| Omeprazole | 27 |
| Quetiapine Fumarate | 26 |
| Diclofenac Sodium | 23 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Physician Assistant Overview
How Joanna Armstrong, PA fits within the Physician Assistant landscape nationally.
150,974
Physician Assistant Providers in US
56
States with Physician Assistant
790
Avg Claims per Provider
Joanna Armstrong, PA's 949 claims are above the specialty average of 790.
Nearby Physician Assistant Providers in Indiana
Other clinicians with the same primary specialty enrolled in Indiana, drawn from the same CMS NPPES roster as Armstrong.
Dr. Mary Abbas
PA-C
Indianapolis, IN
Dr. Alexandra Abbey
PA-C
Indianapolis, IN
Dr. Mackenzie Accorsi
PA-C
La Porte, IN
Dr. Anna Ackermann
PA-C
Indianapolis, IN
Dr. Joshua Ackermann
PA-C
Indianapolis, IN
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 Indiana 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.
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Frequently Asked Questions
What is Joanna Armstrong, PA's specialty? ▼
Joanna Armstrong, PA specializes in Physician Assistant and practices in Indianapolis, Indiana. Credentials: PA.
How much does Joanna Armstrong, PA prescribe under Medicare Part D? ▼
In 2023, Joanna Armstrong, PA wrote 949 Medicare Part D claims totaling $71K in drug costs for 98 beneficiaries.
Where is Joanna Armstrong, PA located? ▼
Joanna Armstrong, PA is located at 1800 N CAPITOL AVE, Indianapolis, IN, 46202. Phone: (317) 962-2894.
What is Joanna Armstrong, PA's NPI number? ▼
Joanna Armstrong, PA's National Provider Identifier (NPI) is 1639290414, issued on 04/02/2007.
Does Joanna Armstrong, PA prescribe more brand-name or generic drugs? ▼
Joanna Armstrong, PA's prescribing is 16% brand-name and 84% generic drugs by claim count, with $52K in brand drug costs.
Does Joanna Armstrong, PA prescribe opioids? ▼
Yes, Joanna Armstrong, PA had 46 opioid claims in 2023 with an opioid prescribing rate of 4.8%.
How many Physician Assistant providers are there in the US? ▼
There are 150,974 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 Joanna Armstrong, PA prescribe most often? ▼
Based on 2023 Medicare Part D data, Joanna Armstrong, PA's most frequently prescribed drugs include Levothyroxine Sodium, Gabapentin, Donepezil Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Joanna Armstrong, PA accept Medicare? ▼
Joanna Armstrong, PA appears in CMS Medicare data with 949 Part D claims and 98 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Joanna Armstrong, PA's credentials? ▼
Joanna Armstrong, PA's NPI is 1639290414 with credentials PA. 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.
Every figure on PlainDoctor is rendered directly from the federal CMS NPPES registry, Medicare Part D, MIPS, and Open Payments records, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of May 2026.