2026 NPPES data Internal Medicine Physician NPI 1619952371 M.D.
Verify on CMS →

COLBY GROSSMAN, M.D.

Internal Medicine Physician in SUMMERVILLE, South Carolina. CMS National Plan and Provider Enumeration System profile including specialty classification, practice address, and Medicare prescribing data when reported.

Federal data — no proprietary rating. PlainDoctor publishes the actual CMS NPPES and Medicare records — NPI registration, specialty, practice location, and prescribing data — without a composite score or editorial opinion on top. Every field traces to a federal source.
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)

What the federal data shows

COLBY GROSSMAN, M.D. filed 6,934 Medicare Part D claims in 2023 as a 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

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). Below this entry. 400–600: 90,619 prescribers (7%). Below this entry. 600–800: 56,224 prescribers (4%). Below this entry. 800–1,000: 40,919 prescribers (3%). Below this entry. 1,000–1,200: 31,827 prescribers (2%). Below this entry. 1,200–1,400: 26,224 prescribers (2%). Below this entry. 1,400–1,600: 21,710 prescribers (2%). Below this entry. 1,600–1,800: 19,072 prescribers (1%). Below this entry. 1,800–2,000: 16,451 prescribers (1%). Below this entry. 2,000–2,200: 213,991 prescribers (16%). This entry sits in this band. This provider 0 2K+ every Part D prescriber (claims/yr), bucketed by value

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 reported

NPI registry status

Active

Issued 12/14/2005

NPI 1619952371

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

6,934 155% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

Specialty distribution in South Carolina

How Internal Medicine Physician compares to other specialties among South Carolina providers

South Carolina providers

Internal Medicine Physician share within South Carolina

1. Internal Medicine Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Internal Medicine Physician share within South Carolina

Specialty board-certification context

Estimated specialty board-certified rate — Internal Medicine Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Internal Medicine Physician ABMS/AOA estimate

Est. board-certified rate (Internal Medicine Physician) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Internal Medicine Physician) — ABMS / AOA estimate

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 a 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. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what GROSSMAN most recently submitted to CMS rather than a vetted directory listing, which is why patients should always confirm the practice is still at this location before scheduling.

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%. These figures capture only Medicare Part D — commercial insurance, Medicaid, and cash-pay prescriptions are not included, and any drug-beneficiary cell under 11 is suppressed by CMS for patient privacy.

Internal Medicine Physician is a high-volume specialty nationwide, with 172,858 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

201 OAKBROOK LN
SUMMERVILLE, SC 29485

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%
Specialty average (est.)

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

claims
Source CMS Medicare Part D Prescriber Public Use File As of 2023
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.

172,858
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.

Compare Internal Medicine Physician nationally: see state-by-state distribution →

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 172,858 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

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