NPI registry status
Active
2026 NPPES data Internal Medicine Physician NPI 1619952371 M.D.
Verify on CMS → Colby Grossman, M.D.
Internal Medicine Physician in Summerville, 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 172,737 in Internal Medicine 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
7K
Medicare Part D claims · 360 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
83%
generic claims · 17% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$734.94
35 payments · CMS Open Payments (Sunshine Act)
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
Colby Grossman, M.D. filed 6,934 Medicare Part D claims in 2023 as an Internal Medicine Physician in Summerville, South Carolina, prescribing 83% generic.
- 7K
- Part D claims, 2023
- 83%
- generic prescribing
- $734.94
- industry payments (Sunshine Act)
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.
Colby Grossman, M.D.'s Medicare Part D volume vs every U.S. prescriber
Total Medicare Part D claims, 2023, across all CMS prescribers nationally
6,934 Top 4% higher than 96% 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)
Colby Grossman, M.D. 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 Colby Grossman, M.D.?
Quality data not reportedPrimary specialty
Internal Medicine Physician
Medicare Part D claims
6,934 155% vs specialty avg
Specialty distribution in South Carolina
How Internal Medicine 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 Internal Medicine 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).
Colby Grossman, M.D. appears in the CMS NPPES registry as an Internal Medicine Physician provider holding M.D. credentials at 201 OAKBROOK LN, Summerville, SC, 29485, with a listed phone of (843) 695-8464. NPI 1619952371 was issued on 12/14/2005.
Medicare Part D records for calendar year 2023 show 6,934 prescription claims written by this provider, covering 360 Medicare beneficiaries and totaling roughly $1.1 million in drug spend, split 17% brand-name and 83% generic by claim count, with an opioid prescribing rate of 2.1%.
Internal Medicine Physician is a high-volume specialty nationwide, with 172,737 enrolled providers across 56 states and an average of 2,716 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 | 1619952371 |
|---|---|
| Specialty | Internal Medicine Physician |
| Credentials | M.D. |
| Gender | Male |
| NPI Issued | 12/14/2005 |
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 Colby Grossman, M.D.. Source: openpaymentsdata.cms.gov.
Total received
$735
Largest payer
Amgen 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
Colby Grossman, M.D. - brand share 17.0%
Internal Medicine Physician average
17% brand-name claims vs 83% generic, on 6,934 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.
6,934
Total Claims
$1.1M
Total Drug Cost
360
Medicare Beneficiaries
Prescribing Breakdown
- 30-Day Fills
- 16,292
- Total Day Supply
- 479,381
- Brand vs Generic
- 17% brand / 83% generic
- Brand Drug Cost
- $926K
- Generic Drug Cost
- $174K
- Opioid Claims
- 143 (2.1% rate)
- Antibiotic Claims
- 203
Patient Demographics
- Average Patient Age
- 75.5 years
- Avg HCC Risk Score
- 1.08
- Gender Split
- 49% female / 51% male
Top Prescribed Drugs (Medicare Part D)
Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.
What Colby Grossman, M.D. prescribes most
Top Medicare Part D drugs by claim count, 2023
- Amlodipine Besylate
Amlodipine Besylate
284 claims
- Levothyroxine Sodium
Levothyroxine Sodium
270 claims
- Rosuvastatin Calcium
Rosuvastatin Calcium
253 claims
- Atorvastatin Calcium
Atorvastatin Calcium
224 claims
- Irbesartan
Irbesartan
223 claims
- Omeprazole
Omeprazole
193 claims
- Hydrochlorothiazide
Hydrochlorothiazide
163 claims
- Potassium Chloride
Potassium Chloride
151 claims
| Drug | Claims |
|---|---|
| Amlodipine Besylate | 284 |
| Levothyroxine Sodium | 270 |
| Rosuvastatin Calcium | 253 |
| Atorvastatin Calcium | 224 |
| Irbesartan | 223 |
| Omeprazole | 193 |
| Hydrochlorothiazide | 163 |
| Potassium Chloride | 151 |
| Metoprolol Succinate | 141 |
| Ezetimibe | 140 |
* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.
Internal Medicine Physician Overview
How Colby Grossman, M.D. fits within the Internal Medicine Physician landscape nationally.
172,737
Internal Medicine Physician Providers in US
56
States with Internal Medicine Physician
2,716
Avg Claims per Provider
Colby Grossman, M.D.'s 6,934 claims are above the specialty average of 2,716.
Nearby Internal Medicine Physician Providers in South Carolina
Other clinicians with the same primary specialty enrolled in South Carolina, drawn from the same CMS NPPES roster as Grossman.
Dr. John Abbott
M.D.
Sumter, SC
Dr. Murad Abdelsalam
MD
Rock Hill, SC
Dr. Mohammed Abdulfatah
MD
Orangeburg, SC
Dr. Amjad Abdulrahman
MD
Irmo, SC
Dr. Elizabeth Abell
MD
Spartanburg, SC
Compare Internal Medicine 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 Internal Medicine 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 Colby Grossman, M.D.'s specialty? ▼
Colby Grossman, M.D. specializes in Internal Medicine Physician and practices in Summerville, South Carolina. Credentials: M.D..
How much does Colby Grossman, M.D. prescribe under Medicare Part D? ▼
In 2023, Colby Grossman, M.D. wrote 6,934 Medicare Part D claims totaling $1.1M in drug costs for 360 beneficiaries.
Where is Colby Grossman, M.D. located? ▼
Colby Grossman, M.D. is located at 201 OAKBROOK LN, Summerville, SC, 29485. Phone: (843) 695-8464.
What is Colby Grossman, M.D.'s NPI number? ▼
Colby Grossman, M.D.'s National Provider Identifier (NPI) is 1619952371, issued on 12/14/2005.
Does Colby Grossman, M.D. prescribe more brand-name or generic drugs? ▼
Colby Grossman, M.D.'s prescribing is 17% brand-name and 83% generic drugs by claim count, with $926K in brand drug costs.
Does Colby Grossman, M.D. prescribe opioids? ▼
Yes, Colby Grossman, M.D. had 143 opioid claims in 2023 with an opioid prescribing rate of 2.1%.
How many Internal Medicine Physician providers are there in the US? ▼
There are 172,737 Internal Medicine Physician providers across 56 states in the US. The average Internal Medicine Physician provider writes 2,716 Medicare Part D claims per year.
What drugs does Colby Grossman, M.D. prescribe most often? ▼
Based on 2023 Medicare Part D data, Colby Grossman, M.D.'s most frequently prescribed drugs include Amlodipine Besylate, Levothyroxine Sodium, Rosuvastatin Calcium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Colby Grossman, M.D. accept Medicare? ▼
Colby Grossman, M.D. appears in CMS Medicare data with 6,934 Part D claims and 360 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Colby Grossman, M.D.'s credentials? ▼
Colby Grossman, M.D.'s NPI is 1619952371 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 (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.