NPI registry status
Active
2026 NPPES data Pain Medicine (Physical Medicine & Rehabilitation) Physician NPI 1275194839 MD PHD
Verify on CMS → Alexander Chamessian, MD PHD
Pain Medicine (Physical Medicine & Rehabilitation) Physician in Creve Coeur, Missouri.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 1,661 in Pain Medicine (Physical Medicine & Rehabilitation) 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
568
Medicare Part D claims · 206 beneficiaries · Pain Medicine (Physical Medicine & Rehabilitation) Physician avg: 1K
Industry payments
$12.0K
26 payments · CMS Open Payments (Sunshine Act)
What the federal data shows
Alexander Chamessian, MD PHD filed 568 Medicare Part D claims in 2024 as a Pain Medicine (Physical Medicine & Rehabilitation) Physician in Creve Coeur, Missouri.
- 568
- Part D claims, 2024
- Likely
- board-certified (heuristic)
- ≥65th
- pct by Part D claim volume (lower-bound band)
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.
Federal trust snapshot
What official records show about Alexander Chamessian, MD PHD
Federal records show an active NPI with Medicare Part D prescribing activity — verifiable registry data, not a proprietary rating.
- Verified
NPI registry status
Active listing in the CMS National Provider Identifier Registry (NPI 1275194839), first enumerated 06/25/2019.
Source: CMS NPPES
- Reported
Medicare Part D participation
Filed 568 Medicare Part D prescription claims in the 2023 CMS public use file — indicates active Medicare prescribing participation.
Source: CMS Part D Prescriber PUF
- Reported
Board certification signal
Heuristic suggests board-certified status based on ABMS-eligible specialty taxonomy plus active CMS participation signals — not a direct ABMS verification.
- Reported
Hospital affiliations
2 CMS Care Compare hospital affiliations on record — practice footprint from the Doctors and Clinicians file.
Source: CMS Care Compare
- Reported
Industry payment transparency
$12.0K in reported industry payments (26 transfers) in 2024 under the federal Sunshine Act — disclosed transfers of value, not a quality rating.
Source: CMS Open Payments
- Not in federal data
Individual sanction lookup
PlainDoctor does not publish per-provider disciplinary determinations. Confirm current license and any individual actions through the state medical board or FSMB verification service.
Source: State medical board / FSMB
This trust snapshot summarizes only what appears in federal CMS/NPPES public records. It is not a composite score, star rating, patient review, or clinical recommendation. PlainDoctor never fabricates reviews or AggregateRating schema.
CMS NPPES provider registry desk
NPI 1275194839 · Pain Medicine (Physical Medicine & Rehabilitation) Physician
NPI-10 · ENUM-RECENT · TAX-NARROW · RX-LIGHT · BOOK-THIN · PHOTO-ENUM
- NPI-10 1275194839
- ENUM-RECENT 2019
- TAX-NARROW 1,661
- RX-LIGHT 568
- BOOK-THIN 18 in Missouri
- PHOTO-ENUM Cale White, MD · 2019
Alexander Chamessian, MD PHD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2024, across all CMS prescribers nationally
568 ≥ 65th percentile 65% of 1,416,883 prescribers are in lower value bands
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.
The percentile is a conservative 100-claim band: it counts only prescribers in lower claim-volume bands. Medicare Part D claim volume is activity context, not a quality measure or recommendation. See methodology § corpus placement.
Source CMS Medicare Part D Prescriber Public Use File · 2024
✓
Board certification likely (heuristic, not verified)
Alexander Chamessian, MD PHD practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 2 hospital affiliations - 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 Alexander Chamessian, MD PHD?
Quality data not reportedPrimary specialty
Pain Medicine (Physical Medicine & Rehabilitation) Physician
Medicare Part D claims
568 59% vs specialty avg
Specialty distribution in Missouri
How Pain Medicine (Physical Medicine & Rehabilitation) Physician compares to other specialties among Missouri 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 Pain Medicine (Physical Medicine & Rehabilitation) 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).
Practice Address
Provider Details
| NPI | 1275194839 |
|---|---|
| Specialty | Pain Medicine (Physical Medicine & Rehabilitation) Physician |
| Credentials | MD PHD |
| Gender | Male |
| NPI Issued | 06/25/2019 |
Hospital and facility affiliations
Facilities where Alexander Chamessian, MD PHD 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.
Post-Acute Physicians OF Missouri, PC
Lake St Louis, MO
Washington University
St Louis, MO
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 Alexander Chamessian, MD PHD. Source: openpaymentsdata.cms.gov.
Total received
$12.0K
Largest payer
Boston Scientific Corporation
Most common payment type
Food and Beverage
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.
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2024.
568
Total Claims
$14K
Total Drug Cost
206
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 821.967
- Total Day Supply
- 23,922
- Generic Drug Cost
- $12K
Patient Demographics
- Average Patient Age
- 65.5 years
- Avg HCC Risk Score
- 1.57
- Gender Split
- 62% female / 38% male
- Age Distribution
- <65: 82, 65-74: 81, 75-84: N/A, 85+: N/A
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2024. Based on Medicare Part D data only.
What Alexander Chamessian, MD PHD prescribes most
Top Medicare Part D drugs by claim count, 2024
- Gabapentin
Gabapentin
143 claims
- Baclofen 55
Baclofen
55 claims
- Duloxetine Hcl 51
Duloxetine Hcl
51 claims
- Tizanidine Hcl 51
Tizanidine Hcl
51 claims
- Celecoxib 35
Celecoxib
35 claims
- Methocarbamol 35
Methocarbamol
35 claims
- Nortriptyline Hcl 19
Nortriptyline Hcl
19 claims
- Topiramate 17
Topiramate
17 claims
| Drug | Claims |
|---|---|
| Gabapentin | 143 |
| Baclofen | 55 |
| Duloxetine Hcl | 51 |
| Tizanidine Hcl | 51 |
| Celecoxib | 35 |
| Methocarbamol | 35 |
| Nortriptyline Hcl | 19 |
| Topiramate | 17 |
| Meloxicam | 16 |
| Cyclobenzaprine Hcl | 15 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
More Pain Medicine (Physical Medicine & Rehabilitation) Physician in MO →
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Pain Medicine (Physical Medicine & Rehabilitation) Physician Overview
How Alexander Chamessian, MD PHD fits within the Pain Medicine (Physical Medicine & Rehabilitation) Physician landscape nationally.
1,661
Pain Medicine (Physical Medicine & Rehabilitation) Physician Providers in US
51
States with Pain Medicine (Physical Medicine & Rehabilitation) Physician
1,399
Avg Claims per Provider
Alexander Chamessian, MD PHD's 568 claims are below the specialty average of 1,399.
Nationwide Pain Medicine (Physical Medicine & Rehabilitation) Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Chamessian, both outside Missouri so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2019)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Pain Medicine (Physical Medicine & Rehabilitation) Physician Providers in Missouri
Other clinicians with the same primary specialty enrolled in Missouri, drawn from the same CMS NPPES roster as Chamessian.
One of 18 Pain Medicine (Physical Medicine & Rehabilitation) Physician providers enrolled in Missouri, 5 are shown here.
Frequently Asked Questions
What is Alexander Chamessian, MD PHD's specialty? ▼
Alexander Chamessian, MD PHD specializes in Pain Medicine (Physical Medicine & Rehabilitation) Physician and practices in Creve Coeur, Missouri. Credentials: MD PHD.
How much does Alexander Chamessian, MD PHD prescribe under Medicare Part D? ▼
In 2024, Alexander Chamessian, MD PHD wrote 568 Medicare Part D claims totaling $14K in drug costs for 206 beneficiaries.
Where is Alexander Chamessian, MD PHD located? ▼
Alexander Chamessian, MD PHD is located at 1044 N MASON RD, Creve Coeur, MO, 63141. Phone: (314) 996-8631.
What is Alexander Chamessian, MD PHD's NPI number? ▼
Alexander Chamessian, MD PHD's National Provider Identifier (NPI) is 1275194839, issued on 06/25/2019.
How many Pain Medicine (Physical Medicine & Rehabilitation) Physician providers are there in the US? ▼
There are 1,661 Pain Medicine (Physical Medicine & Rehabilitation) Physician providers across 51 states in the US. The average Pain Medicine (Physical Medicine & Rehabilitation) Physician provider writes 1,399 Medicare Part D claims per year.
What drugs does Alexander Chamessian, MD PHD prescribe most often? ▼
Based on 2024 Medicare Part D data, Alexander Chamessian, MD PHD's most frequently prescribed drugs include Gabapentin, Baclofen, Duloxetine Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Alexander Chamessian, MD PHD accept Medicare? ▼
Alexander Chamessian, MD PHD appears in CMS Medicare data with 568 Part D claims and 206 Medicare beneficiaries in 2024. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Alexander Chamessian, MD PHD's credentials? ▼
Alexander Chamessian, MD PHD's NPI is 1275194839 with credentials MD PHD. 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 (2024). 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 August 2026 (NPPES) / 2024 (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
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 August 2026.