NPI registry status
Active
2026 NPPES data Hematology & Oncology Physician NPI 1144546557 MD
Verify on CMS → Joanna Grabska, MD
Hematology & Oncology Physician in Greenville, 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 11,232 in Hematology & Oncology 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
1K
Medicare Part D claims · 288 beneficiaries · Hematology & Oncology Physician avg: 847
What the federal data shows
Joanna Grabska, MD filed 1,151 Medicare Part D claims in 2023 as a Hematology & Oncology Physician in Greenville, South Carolina.
- 1K
- Part D claims, 2023
- Likely
- board-certified (heuristic)
- ≥77th
- 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 Joanna Grabska, MD
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 1144546557), first enumerated 04/09/2010.
Source: CMS NPPES
- Reported
Medicare Part D participation
Filed 1,151 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
- 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 1144546557 · Hematology & Oncology Physician
NPI-10 · ENUM-MID · TAX-MID · RX-MID · BOOK-THIN · PHOTO-ENUM
- NPI-10 1144546557
- ENUM-MID 2010
- TAX-MID 11K Hematology &
- RX-MID 1,151
- BOOK-THIN 147 in South Carolina
- PHOTO-ENUM Victor Chiu · 2010
Joanna Grabska, MD's Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
1,151 ≥ 77th percentile 77% of 1,370,886 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 · 2023
✓
Board certification likely (heuristic, not verified)
Joanna Grabska, MD 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 Joanna Grabska, MD?
Quality data not reportedPrimary specialty
Hematology & Oncology Physician
Medicare Part D claims
1,151 36% vs specialty avg
Specialty distribution in South Carolina
How Hematology & Oncology 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 Hematology & Oncology 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 | 1144546557 |
|---|---|
| Specialty | Hematology & Oncology Physician |
| Credentials | MD |
| Gender | Female |
| NPI Issued | 04/09/2010 |
Hospital and facility affiliations
Facilities where Joanna Grabska, MD 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.
Spartanburg Medical Center
★★☆☆☆ 2/5
Spartanburg, SC
Acute Care Hospitals
CMS CCN: 420007
Bon Secours Medical Group Greenville Specialty Care LLC
Greenville, SC
Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).
Medicare Part D Prescribing Data
CMS Medicare Part D prescriber-level data for calendar year 2023.
1,151
Total Claims
$1.3M
Total Drug Cost
288
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 2,173
- Total Day Supply
- 61,919
- Generic Drug Cost
- $87K
- Opioid Claims
- 51 (4.4% rate)
- Antibiotic Claims
- 34
Patient Demographics
- Average Patient Age
- 71.8 years
- Avg HCC Risk Score
- 1.72
- Gender Split
- 88% female / 13% male
- Age Distribution
- <65: 22, 65-74: 172, 75-84: 82, 85+: 12
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Joanna Grabska, MD prescribes most
Top Medicare Part D drugs by claim count, 2023
- Letrozole
Letrozole
266 claims
- Anastrozole
Anastrozole
170 claims
- Tamoxifen Citrate 52
Tamoxifen Citrate
52 claims
- Xarelto 42
Xarelto
42 claims
- Ibrance 38
Ibrance
38 claims
- Ondansetron Hcl 30
Ondansetron Hcl
30 claims
- Potassium Chloride 28
Potassium Chloride
28 claims
- Pantoprazole Sodium 27
Pantoprazole Sodium
27 claims
| Drug | Claims |
|---|---|
| Letrozole | 266 |
| Anastrozole | 170 |
| Tamoxifen Citrate | 52 |
| Xarelto Rivaroxaban | 42 |
| Ibrance Palbociclib | 38 |
| Ondansetron Hcl | 30 |
| Potassium Chloride | 28 |
| Pantoprazole Sodium | 27 |
| Mirtazapine | 25 |
| Eliquis Apixaban | 24 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
More Hematology & Oncology Physician in SC →
All providers in South Carolina →
Compare specialties →
Hematology & Oncology Physician Overview
How Joanna Grabska, MD fits within the Hematology & Oncology Physician landscape nationally.
11,232
Hematology & Oncology Physician Providers in US
54
States with Hematology & Oncology Physician
847
Avg Claims per Provider
Joanna Grabska, MD's 1,151 claims are above the specialty average of 847.
Nationwide Hematology & Oncology Physician peers with similar MIPS or enrollment year
Two federal-record peer sets for Grabska, both outside South Carolina so the neighborhoods are not geographic containment.
Same NPPES enumeration year (2010)
Same-specialty clinicians who entered the NPI registry in the same calendar year, outside this state.
Nearby Hematology & Oncology Physician Providers in South Carolina
Other clinicians with the same primary specialty enrolled in South Carolina, drawn from the same CMS NPPES roster as Grabska.
One of 147 Hematology & Oncology Physician providers enrolled in South Carolina, 5 are shown here.
Dr. Mary Ackerman
MD
Columbia, SC
Dr. Samuel Adediran
M.D.,
Spartanburg, SC
Dr. Priyal Agarwal
MD
Charleston, SC
Dr. Steven Akman
MD
Charleston, SC
Dr. Jonathan Alexander
M.D.
Charleston, SC
Compare Hematology & Oncology Physician nationally: see state-by-state distribution →
Frequently Asked Questions
What is Joanna Grabska, MD's specialty? ▼
Joanna Grabska, MD specializes in Hematology & Oncology Physician and practices in Greenville, South Carolina. Credentials: MD.
How much does Joanna Grabska, MD prescribe under Medicare Part D? ▼
In 2023, Joanna Grabska, MD wrote 1,151 Medicare Part D claims totaling $1.3M in drug costs for 288 beneficiaries.
Where is Joanna Grabska, MD located? ▼
Joanna Grabska, MD is located at 104 INNOVATION DR. STE. 2000, Greenville, SC, 29607. Phone: (864) 603-6300.
What is Joanna Grabska, MD's NPI number? ▼
Joanna Grabska, MD's National Provider Identifier (NPI) is 1144546557, issued on 04/09/2010.
Does Joanna Grabska, MD prescribe opioids? ▼
Yes, Joanna Grabska, MD had 51 opioid claims in 2023 with an opioid prescribing rate of 4.4%.
How many Hematology & Oncology Physician providers are there in the US? ▼
There are 11,232 Hematology & Oncology Physician providers across 54 states in the US. The average Hematology & Oncology Physician provider writes 847 Medicare Part D claims per year.
What drugs does Joanna Grabska, MD prescribe most often? ▼
Based on 2023 Medicare Part D data, Joanna Grabska, MD's most frequently prescribed drugs include Letrozole, Anastrozole, Tamoxifen Citrate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Joanna Grabska, MD accept Medicare? ▼
Joanna Grabska, MD appears in CMS Medicare data with 1,151 Part D claims and 288 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Joanna Grabska, MD's credentials? ▼
Joanna Grabska, MD's NPI is 1144546557 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
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.