NPI registry status
Active
2026 NPPES data Gastroenterology Physician NPI 1326079278 M.D.
Verify on CMS → Mark Flasar, M.D.
Gastroenterology Physician in Annapolis, Maryland.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 17,061 in Gastroenterology 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
929
Medicare Part D claims · 247 beneficiaries · Gastroenterology Physician avg: 848
Generic prescribing
82%
generic claims · 18% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$38.5K
134 payments · CMS Open Payments (Sunshine Act)
Source: CMS Medicare Part D Prescriber Public Use File, 2024
What the federal data shows
Mark Flasar, M.D. filed 929 Medicare Part D claims in 2024 as a Gastroenterology Physician in Annapolis, Maryland, prescribing 82% generic.
- 929
- Part D claims, 2024
- 82%
- generic prescribing
- Likely
- board-certified (heuristic)
- ≥74th
- 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 Mark Flasar, M.D.
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 1326079278), first enumerated 07/06/2006.
Source: CMS NPPES
- Reported
Medicare Part D participation
Filed 929 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
1 CMS Care Compare hospital affiliation on record — practice footprint from the Doctors and Clinicians file.
Source: CMS Care Compare
- Reported
Industry payment transparency
$38.5K in reported industry payments (134 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 1326079278 · Gastroenterology Physician
NPI-10 · ENUM-LEGACY · TAX-MID · RX-LIGHT · BOOK-THIN · PHOTO-ENUM
- NPI-10 1326079278
- ENUM-LEGACY 2006
- TAX-MID 17K Gastroenterology Physician
- RX-LIGHT 929
- BOOK-THIN 424 in Maryland
- PHOTO-ENUM Herman Rusche · 2006
Mark Flasar, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2024, across all CMS prescribers nationally
929 ≥ 74th percentile 74% 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)
Mark Flasar, M.D. 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 Mark Flasar, M.D.?
Quality data not reportedPrimary specialty
Gastroenterology Physician
Medicare Part D claims
929 10% vs specialty avg
Specialty distribution in Maryland
How Gastroenterology Physician compares to other specialties among Maryland 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 Gastroenterology 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 | 1326079278 |
|---|---|
| Specialty | Gastroenterology Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 07/06/2006 |
Hospital and facility affiliations
Facilities where Mark Flasar, M.D. 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.
Anne Arundel Gastroenterology Associates, P.A.
Bowie, MD
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 Mark Flasar, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$38.5K
Largest payer
ABBVIE INC.
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.
Brand vs generic prescribing mix · Typical
Mark Flasar, M.D. - brand share 18.0%
Gastroenterology Physician average
18% brand-name claims vs 82% generic, on 929 2024 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 2024.
929
Total Claims
$2.2M
Total Drug Cost
247
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 1,922.433
- Total Day Supply
- 55,874
- Brand vs Generic
- 18% brand / 82% generic
- Brand Drug Cost
- $2.1M
- Generic Drug Cost
- $100K
- Antibiotic Claims
- 16
Patient Demographics
- Average Patient Age
- 74.3 years
- Avg HCC Risk Score
- 1.06
- Gender Split
- 53% female / 47% male
- Age Distribution
- <65: 14, 65-74: 111, 75-84: 102, 85+: 20
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2024. Based on Medicare Part D data only.
What Mark Flasar, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2024
- Pantoprazole Sodium
Pantoprazole Sodium
275 claims
- Mesalamine 88
Mesalamine
88 claims
- Omeprazole 76
Omeprazole
76 claims
- Famotidine 67
Famotidine
67 claims
- Humira(Cf) Pen 53
Humira(Cf) Pen
53 claims
- Stelara 42
Stelara
42 claims
- Rabeprazole Sodium 27
Rabeprazole Sodium
27 claims
- Dicyclomine Hcl 22
Dicyclomine Hcl
22 claims
| Drug | Claims |
|---|---|
| Pantoprazole Sodium | 275 |
| Mesalamine | 88 |
| Omeprazole | 76 |
| Famotidine | 67 |
| Humira(Cf) Pen Adalimumab | 53 |
| Stelara Ustekinumab | 42 |
| Rabeprazole Sodium | 27 |
| Dicyclomine Hcl | 22 |
| Lansoprazole | 21 |
| Budesonide Ec Budesonide | 19 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Gastroenterology Physician Overview
How Mark Flasar, M.D. fits within the Gastroenterology Physician landscape nationally.
17,061
Gastroenterology Physician Providers in US
54
States with Gastroenterology Physician
848
Avg Claims per Provider
Mark Flasar, M.D.'s 929 claims are above the specialty average of 848.
Nationwide Gastroenterology Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Flasar, both outside Maryland so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2006)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Gastroenterology Physician Providers in Maryland
Other clinicians with the same primary specialty enrolled in Maryland, drawn from the same CMS NPPES roster as Flasar.
One of 424 Gastroenterology Physician providers enrolled in Maryland, 5 are shown here.
Dr. Maaza Abdi
M.D.
Baltimore, MD
Dr. Tsion Abdi
MD
Baltimore, MD
Dr. Hamza Abdulla
M.D.
Easton, MD
Dr. Thomas Abernathy
M.D.
Catonsville, MD
Dr. Ruben Acosta
M.D.
Silver Spring, MD
Compare Gastroenterology Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is Mark Flasar, M.D.'s specialty? ▼
Mark Flasar, M.D. specializes in Gastroenterology Physician and practices in Annapolis, Maryland. Credentials: M.D..
How much does Mark Flasar, M.D. prescribe under Medicare Part D? ▼
In 2024, Mark Flasar, M.D. wrote 929 Medicare Part D claims totaling $2.2M in drug costs for 247 beneficiaries.
Where is Mark Flasar, M.D. located? ▼
Mark Flasar, M.D. is located at 820 BESTGATE RD, Annapolis, MD, 21401. Phone: (410) 224-2116.
What is Mark Flasar, M.D.'s NPI number? ▼
Mark Flasar, M.D.'s National Provider Identifier (NPI) is 1326079278, issued on 07/06/2006.
Does Mark Flasar, M.D. prescribe more brand-name or generic drugs? ▼
Mark Flasar, M.D.'s prescribing is 18% brand-name and 82% generic drugs by claim count, with $2.1M in brand drug costs.
How many Gastroenterology Physician providers are there in the US? ▼
There are 17,061 Gastroenterology Physician providers across 54 states in the US. The average Gastroenterology Physician provider writes 848 Medicare Part D claims per year.
What drugs does Mark Flasar, M.D. prescribe most often? ▼
Based on 2024 Medicare Part D data, Mark Flasar, M.D.'s most frequently prescribed drugs include Pantoprazole Sodium, Mesalamine, Omeprazole. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Mark Flasar, M.D. accept Medicare? ▼
Mark Flasar, M.D. appears in CMS Medicare data with 929 Part D claims and 247 Medicare beneficiaries in 2024. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Mark Flasar, M.D.'s credentials? ▼
Mark Flasar, M.D.'s NPI is 1326079278 with credentials M.D.. 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.