2026 NPPES data Geriatric Medicine (Internal Medicine) Physician NPI 1699886309 DO
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MARK GUNBY, DO

Geriatric Medicine (Internal Medicine) Physician in SAINT LOUIS, Missouri. 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
19K
Medicare Part D claims · 1K beneficiaries · Geriatric Medicine (Internal Medicine) Physician avg: 4K
Generic prescribing
89%
generic claims · 11% brand-name · higher generic rates reduce patient out-of-pocket costs
Industry payments
$61.03
4 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

MARK GUNBY, DO filed 18,531 Medicare Part D claims in 2023 as a Geriatric Medicine (Internal Medicine) Physician in SAINT LOUIS, Missouri, prescribing 89% generic.

19K
Part D claims, 2023
89%
generic prescribing
$61.03
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.

MARK GUNBY, DO's Medicare Part D volume vs every U.S. prescriber

Total Medicare Part D claims, 2023 — across all CMS prescribers nationally

18,531 Top 2% higher than 98% 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)

MARK GUNBY, DO 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 MARK GUNBY, DO?

Quality data not reported

NPI registry status

Active

Issued 08/31/2006

NPI 1699886309

Primary specialty

Geriatric Medicine (Internal Medicine) Physician

Niche

4,161 US NPIs in this specialty

Medicare Part D claims

18,531 316% vs specialty avg

2023 prescription claims

Specialty avg: 4,450

Specialty distribution in Missouri

How Geriatric Medicine (Internal Medicine) Physician compares to other specialties among Missouri providers

Missouri providers

Geriatric Medicine (Internal Medicine) Physician share within Missouri

1. Geriatric Medicine (Internal Medicine) Physician42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Geriatric Medicine (Internal Medicine) Physician share within Missouri

Specialty board-certification context

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

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

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

0%100%78%
Est. board-certified rate (Geriatric Medicine (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).

MARK GUNBY, DO appears in the CMS NPPES registry as a Geriatric Medicine (Internal Medicine) Physician provider holding DO credentials at 3844 S LINDBERGH BLVD STE 120, SAINT LOUIS, MO, 63127, with a listed phone of (314) 525-0490. NPI 1699886309 was issued on 08/31/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what GUNBY 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 18,531 prescription claims written by this provider, covering 1,133 Medicare beneficiaries and totaling roughly $1.4 million in drug spend, split 11% brand-name and 89% generic by claim count, with an opioid prescribing rate of 3.4%. 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.

Geriatric Medicine (Internal Medicine) Physician is a narrow specialty nationwide, with 4,161 enrolled providers across 52 states and an average of 4,450 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

3844 S LINDBERGH BLVD STE 120
SAINT LOUIS, MO 63127

Provider Details

NPI 1699886309
Specialty Geriatric Medicine (Internal Medicine) Physician
Credentials DO
Gender Male
NPI Issued 08/31/2006

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 GUNBY, DO. Source: openpaymentsdata.cms.gov.

Total received

$61

Largest payer

Novo Nordisk 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 GUNBY, DO — brand share 11.0%
Specialty average (est.)

11% brand-name claims vs 89% generic, on 18,531 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.

18,531
Total Claims
$1.4M
Total Drug Cost
1,133
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
39,865
Total Day Supply
1,150,386
Brand vs Generic
11% brand / 89% generic
Brand Drug Cost
$1.1M
Generic Drug Cost
$308K
Opioid Claims
629 (3.4% rate)
Antibiotic Claims
314

Patient Demographics

Average Patient Age
75.8 years
Avg HCC Risk Score
1.10
Gender Split
59% female / 41% male
Age Distribution
<65: 55, 65-74: 498, 75-84: 375, 85+: 205

Top Prescribed Drugs (Medicare Part D)

Top drugs by claim count for calendar year 2023. Based on Medicare Part D data only.

What MARK GUNBY, DO 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
Atorvastatin Calcium
1,083
Lisinopril
919
Amlodipine Besylate
704
Levothyroxine Sodium
606
Simvastatin
507
Omeprazole
389
Gabapentin
386
Rosuvastatin Calcium
367
Metoprolol Succinate
343
Tramadol Hcl
339

* Counts below 11 are suppressed by CMS for patient privacy. Generic names shown where available from CMS Part D data.

Geriatric Medicine (Internal Medicine) Physician Overview

How MARK GUNBY, DO fits within the Geriatric Medicine (Internal Medicine) Physician landscape nationally.

4,161
Geriatric Medicine (Internal Medicine) Physician Providers in US
52
States with Geriatric Medicine (Internal Medicine) Physician
4,450
Avg Claims per Provider

MARK GUNBY, DO's 18,531 claims are above the specialty average of 4,450.

Nearby Geriatric Medicine (Internal Medicine) Physician Providers in Missouri

Other clinicians with the same primary specialty enrolled in Missouri, drawn from the same CMS NPPES roster as GUNBY.

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

Frequently Asked Questions

What is MARK GUNBY, DO's specialty?
MARK GUNBY, DO specializes in Geriatric Medicine (Internal Medicine) Physician and practices in SAINT LOUIS, Missouri. Credentials: DO.
How much does MARK GUNBY, DO prescribe under Medicare Part D?
In 2023, MARK GUNBY, DO wrote 18,531 Medicare Part D claims totaling $1.4M in drug costs for 1,133 beneficiaries.
Where is MARK GUNBY, DO located?
MARK GUNBY, DO is located at 3844 S LINDBERGH BLVD STE 120, SAINT LOUIS, MO, 63127. Phone: (314) 525-0490.
What is MARK GUNBY, DO's NPI number?
MARK GUNBY, DO's National Provider Identifier (NPI) is 1699886309, issued on 08/31/2006.
Does MARK GUNBY, DO prescribe more brand-name or generic drugs?
MARK GUNBY, DO's prescribing is 11% brand-name and 89% generic drugs by claim count, with $1.1M in brand drug costs.
Does MARK GUNBY, DO prescribe opioids?
Yes, MARK GUNBY, DO had 629 opioid claims in 2023 with an opioid prescribing rate of 3.4%.
How many Geriatric Medicine (Internal Medicine) Physician providers are there in the US?
There are 4,161 Geriatric Medicine (Internal Medicine) Physician providers across 52 states in the US. The average Geriatric Medicine (Internal Medicine) Physician provider writes 4,450 Medicare Part D claims per year.
What drugs does MARK GUNBY, DO prescribe most often?
Based on 2023 Medicare Part D data, MARK GUNBY, DO's most frequently prescribed drugs include Atorvastatin Calcium, Lisinopril, Amlodipine Besylate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does MARK GUNBY, DO accept Medicare?
MARK GUNBY, DO appears in CMS Medicare data with 18,531 Part D claims and 1,133 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify MARK GUNBY, DO's credentials?
MARK GUNBY, DO's NPI is 1699886309 with credentials DO. 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