2026 NPPES data Critical Care Medicine (Internal Medicine) Physician NPI 1891772208 M.D.
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DAVID GUAN, M.D.

Critical Care Medicine (Internal Medicine) Physician in CHATTANOOGA, Tennessee. 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
723
Medicare Part D claims · 75 beneficiaries · Critical Care Medicine (Internal Medicine) Physician avg: 1K
Generic prescribing
60%
generic claims · 40% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

DAVID GUAN, M.D. filed 723 Medicare Part D claims in 2023 as a Critical Care Medicine (Internal Medicine) Physician in CHATTANOOGA, Tennessee, prescribing 60% generic.

723
Part D claims, 2023
60%
generic prescribing
Likely
board-certified (heuristic)

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.

DAVID GUAN, M.D.'s Medicare Part D volume vs every U.S. prescriber

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

723 Top 29% higher than 71% 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%). This entry sits in this band. 800–1,000: 40,919 prescribers (3%). Above this entry. 1,000–1,200: 31,827 prescribers (2%). Above this entry. 1,200–1,400: 26,224 prescribers (2%). Above this entry. 1,400–1,600: 21,710 prescribers (2%). Above this entry. 1,600–1,800: 19,072 prescribers (1%). Above this entry. 1,800–2,000: 16,451 prescribers (1%). Above this entry. 2,000–2,200: 213,991 prescribers (16%). Above this entry. 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 certification likely (heuristic — not verified)

DAVID GUAN, M.D. practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 1 hospital affiliation — 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 DAVID GUAN, M.D.?

Quality data not reported

NPI registry status

Active

Issued 12/28/2005

NPI 1891772208

Primary specialty

Critical Care Medicine (Internal Medicine) Physician

Mid-sized

6,631 US NPIs in this specialty

Medicare Part D claims

723 32% vs specialty avg

2023 prescription claims

Specialty avg: 1,069

Specialty distribution in Tennessee

How Critical Care Medicine (Internal Medicine) Physician compares to other specialties among Tennessee providers

Tennessee providers

Critical Care Medicine (Internal Medicine) Physician share within Tennessee

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

Specialty board-certification context

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

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

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

0%100%78%
Est. board-certified rate (Critical Care 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).

DAVID GUAN, M.D. appears in the CMS NPPES registry as a Critical Care Medicine (Internal Medicine) Physician provider holding M.D. credentials at 1814 MCCALLIE AVE, CHATTANOOGA, TN, 37404, with a listed phone of (423) 208-9030. NPI 1891772208 was issued on 12/28/2005. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what GUAN 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 723 prescription claims written by this provider, covering 75 Medicare beneficiaries and totaling roughly $219K in drug spend, split 40% brand-name and 60% generic by claim count. 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.

Critical Care Medicine (Internal Medicine) Physician is a mid-sized specialty nationwide, with 6,631 enrolled providers across 53 states and an average of 1,069 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

1814 MCCALLIE AVE
CHATTANOOGA, TN 37404

Provider Details

NPI 1891772208
Specialty Critical Care Medicine (Internal Medicine) Physician
Credentials M.D.
Gender Male
NPI Issued 12/28/2005

Hospital and facility affiliations

Facilities where DAVID GUAN, M.D. 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.

SOUTHEASTERN PHYSICIAN SERVICES PC
CLARKSVILLE, TN

Affiliations sourced from CMS Doctors and Clinicians National Downloadable File; hospital ratings from CMS Hospital General Information dataset (cross-referenced by facility name + state).

Brand vs generic prescribing mix · Above average

DAVID GUAN, M.D. — brand share 40.0%
Specialty average (est.)

40% brand-name claims vs 60% generic, on 723 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.

723
Total Claims
$219K
Total Drug Cost
75
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
855
Total Day Supply
24,165
Brand vs Generic
40% brand / 60% generic
Brand Drug Cost
$199K
Generic Drug Cost
$20K
Antibiotic Claims
23

Patient Demographics

Average Patient Age
64.8 years
Avg HCC Risk Score
2.22
Gender Split
63% female / 37% male
Age Distribution
<65: 33, 65-74: 30, 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 DAVID GUAN, 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
Zolpidem Tartrate
122
Albuterol Sulfate Hfa
Albuterol Sulfate
105
Dextroamphetamine-Amphetamine
Dextroamphetamine/Amphetamine
55
Methylphenidate Hcl
42
Breo Ellipta
Fluticasone/Vilanterol
29
Clonazepam
27
Spiriva Handihaler
Tiotropium Bromide
27
Symbicort
Budesonide/Formoterol Fumarate
26
Vyvanse
Lisdexamfetamine Dimesylate
22
Trelegy Ellipta
Fluticasone/Umeclidin/Vilanter
21

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

Critical Care Medicine (Internal Medicine) Physician Overview

How DAVID GUAN, M.D. fits within the Critical Care Medicine (Internal Medicine) Physician landscape nationally.

6,631
Critical Care Medicine (Internal Medicine) Physician Providers in US
53
States with Critical Care Medicine (Internal Medicine) Physician
1,069
Avg Claims per Provider

DAVID GUAN, M.D.'s 723 claims are below the specialty average of 1,069.

Nearby Critical Care Medicine (Internal Medicine) Physician Providers in Tennessee

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

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

Frequently Asked Questions

What is DAVID GUAN, M.D.'s specialty?
DAVID GUAN, M.D. specializes in Critical Care Medicine (Internal Medicine) Physician and practices in CHATTANOOGA, Tennessee. Credentials: M.D..
How much does DAVID GUAN, M.D. prescribe under Medicare Part D?
In 2023, DAVID GUAN, M.D. wrote 723 Medicare Part D claims totaling $219K in drug costs for 75 beneficiaries.
Where is DAVID GUAN, M.D. located?
DAVID GUAN, M.D. is located at 1814 MCCALLIE AVE, CHATTANOOGA, TN, 37404. Phone: (423) 208-9030.
What is DAVID GUAN, M.D.'s NPI number?
DAVID GUAN, M.D.'s National Provider Identifier (NPI) is 1891772208, issued on 12/28/2005.
Does DAVID GUAN, M.D. prescribe more brand-name or generic drugs?
DAVID GUAN, M.D.'s prescribing is 40% brand-name and 60% generic drugs by claim count, with $199K in brand drug costs.
How many Critical Care Medicine (Internal Medicine) Physician providers are there in the US?
There are 6,631 Critical Care Medicine (Internal Medicine) Physician providers across 53 states in the US. The average Critical Care Medicine (Internal Medicine) Physician provider writes 1,069 Medicare Part D claims per year.
What drugs does DAVID GUAN, M.D. prescribe most often?
Based on 2023 Medicare Part D data, DAVID GUAN, M.D.'s most frequently prescribed drugs include Zolpidem Tartrate, Albuterol Sulfate Hfa, Dextroamphetamine-Amphetamine. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does DAVID GUAN, M.D. accept Medicare?
DAVID GUAN, M.D. appears in CMS Medicare data with 723 Part D claims and 75 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify DAVID GUAN, M.D.'s credentials?
DAVID GUAN, M.D.'s NPI is 1891772208 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