NPI registry status
Active
2026 NPPES data Neurology Physician NPI 1770214546 MD
Verify on CMS → Krystina Callahan, MD
Neurology Physician in Charleston, South Carolina.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 19,866 in Neurology 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
181
Medicare Part D claims · 45 beneficiaries · Neurology Physician avg: 1K
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Krystina Callahan, MD filed 181 Medicare Part D claims in 2023 as a Neurology Physician in Charleston, South Carolina.
- 181
- Part D claims, 2023
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.
Krystina Callahan, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
181 35th percentile higher than 35% 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)
Krystina Callahan, 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 Krystina Callahan, MD?
Quality data not reportedPrimary specialty
Neurology Physician
Medicare Part D claims
181 86% vs specialty avg
Specialty distribution in South Carolina
How Neurology Physician compares to other specialties among South Carolina 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 Neurology 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).
Krystina Callahan, MD appears in the CMS NPPES registry as a Neurology Physician provider holding MD credentials at 169 ASHLEY AVE, Charleston, SC, 29425, with a listed phone of (843) 792-3221. NPI 1770214546 was issued on 06/22/2022.
Medicare Part D records for calendar year 2023 show 181 prescription claims written by this provider, covering 45 Medicare beneficiaries and totaling roughly $29K in drug spend.
Neurology Physician is a mid-sized specialty nationwide, with 19,866 enrolled providers across 54 states and an average of 1,309 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 | 1770214546 |
|---|---|
| Specialty | Neurology Physician |
| Credentials | MD |
| Gender | Female |
| NPI Issued | 06/22/2022 |
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
181
Total Claims
$29K
Total Drug Cost
45
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 255
- Total Day Supply
- 7,375
- Generic Drug Cost
- $3K
Patient Demographics
- Average Patient Age
- 63.1 years
- Avg HCC Risk Score
- 1.96
- Gender Split
- 42% female / 58% male
- Age Distribution
- <65: 17, 65-74: 19, 75-84: N/A, 85+: N/A
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Krystina Callahan, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Atorvastatin Calcium
Atorvastatin Calcium
26 claims
- Clopidogrel
Clopidogrel
16 claims
- Zonisamide
Zonisamide
13 claims
- Spironolactone
Spironolactone
12 claims
| Drug | Claims |
|---|---|
| Atorvastatin Calcium | 26 |
| Clopidogrel Clopidogrel Bisulfate | 16 |
| Zonisamide | 13 |
| Spironolactone | 12 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Neurology Physician Overview
How Krystina Callahan, MD fits within the Neurology Physician landscape nationally.
19,866
Neurology Physician Providers in US
54
States with Neurology Physician
1,309
Avg Claims per Provider
Krystina Callahan, MD's 181 claims are below the specialty average of 1,309.
Nearby Neurology Physician Providers in South Carolina
Other clinicians with the same primary specialty enrolled in South Carolina, drawn from the same CMS NPPES roster as Callahan.
Dr. Line Abdul Rahman
MD
Charleston, SC
Dr. Eunice Abrams
M.D.
Florence, SC
Dr. John Absher
M.D.
Greenville, SC
Dr. Ahmad Abu Qdais
MD
Charleston, SC
Dr. Julian Adams
M.D.
Columbia, SC
Compare Neurology Physician 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 South Carolina medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Neurology 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.
Healthcare Guides
Learn more about finding, verifying, and understanding healthcare providers.
How to Find a Doctor
Step-by-step guide to choosing a provider
Verify Credentials
Check NPI, board certification & license status
Medical Specialties Explained
Who treats what and how specialties differ
Understanding Medicare Claims Data
What prescribing data reveals about a provider
In-Network vs Out-of-Network
How insurance networks affect your costs
Telehealth Guide
Virtual care options and coverage in 2026
Explore South Carolina
Frequently Asked Questions
What is Krystina Callahan, MD's specialty? ▼
Krystina Callahan, MD specializes in Neurology Physician and practices in Charleston, South Carolina. Credentials: MD.
How much does Krystina Callahan, MD prescribe under Medicare Part D? ▼
In 2023, Krystina Callahan, MD wrote 181 Medicare Part D claims totaling $29K in drug costs for 45 beneficiaries.
Where is Krystina Callahan, MD located? ▼
Krystina Callahan, MD is located at 169 ASHLEY AVE, Charleston, SC, 29425. Phone: (843) 792-3221.
What is Krystina Callahan, MD's NPI number? ▼
Krystina Callahan, MD's National Provider Identifier (NPI) is 1770214546, issued on 06/22/2022.
How many Neurology Physician providers are there in the US? ▼
There are 19,866 Neurology Physician providers across 54 states in the US. The average Neurology Physician provider writes 1,309 Medicare Part D claims per year.
What drugs does Krystina Callahan, MD prescribe most often? ▼
Based on 2023 Medicare Part D data, Krystina Callahan, MD's most frequently prescribed drugs include Atorvastatin Calcium, Clopidogrel, Zonisamide. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Krystina Callahan, MD accept Medicare? ▼
Krystina Callahan, MD appears in CMS Medicare data with 181 Part D claims and 45 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Krystina Callahan, MD's credentials? ▼
Krystina Callahan, MD's NPI is 1770214546 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.