2026 NPPES data Internal Medicine Physician NPI 1053371666 M.D.
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CHARLES COFAS, M.D.

Internal Medicine Physician in KLAMATH FALLS, Oregon. 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
5K
Medicare Part D claims · 373 beneficiaries · Internal Medicine Physician avg: 3K
Generic prescribing
91%
generic claims · 9% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

CHARLES COFAS, M.D. filed 4,766 Medicare Part D claims in 2023 as a Internal Medicine Physician in KLAMATH FALLS, Oregon, prescribing 91% generic.

5K
Part D claims, 2023
91%
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.

CHARLES COFAS, M.D.'s Medicare Part D volume vs every U.S. prescriber

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

4,766 Top 7% higher than 93% 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 certification likely (heuristic — not verified)

CHARLES COFAS, M.D. 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 CHARLES COFAS, M.D.?

Quality data not reported

NPI registry status

Active

Issued 03/27/2006

NPI 1053371666

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

4,766 75% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

Specialty distribution in Oregon

How Internal Medicine Physician compares to other specialties among Oregon providers

Oregon providers

Internal Medicine Physician share within Oregon

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

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).

CHARLES COFAS, M.D. appears in the CMS NPPES registry as a Internal Medicine Physician provider holding M.D. credentials at 2640 BIEHN ST STE 4, KLAMATH FALLS, OR, 97601, with a listed phone of (541) 882-3818. NPI 1053371666 was issued on 03/27/2006. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what COFAS 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 4,766 prescription claims written by this provider, covering 373 Medicare beneficiaries and totaling roughly $370K in drug spend, split 9% brand-name and 91% generic by claim count, with an opioid prescribing rate of 0.7%. 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

2640 BIEHN ST STE 4
KLAMATH FALLS, OR 97601

Provider Details

NPI 1053371666
Specialty Internal Medicine Physician
Credentials M.D.
Gender Male
NPI Issued 03/27/2006

Hospital and facility affiliations

Facilities where CHARLES COFAS, 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.

COFAS INC
KLAMATH FALLS, OR
SKY LAKES MEDICAL CENTER INC
KLAMATH FALLS, OR

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 · Generic-heavy

CHARLES COFAS, M.D. — brand share 9.0%
Specialty average (est.)

9% brand-name claims vs 91% generic, on 4,766 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.

4,766
Total Claims
$370K
Total Drug Cost
373
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
11,877
Total Day Supply
351,787
Brand vs Generic
9% brand / 91% generic
Brand Drug Cost
$283K
Generic Drug Cost
$84K
Opioid Claims
35 (0.7% rate)
Antibiotic Claims
58

Patient Demographics

Average Patient Age
75.2 years
Avg HCC Risk Score
0.99
Gender Split
52% female / 48% male
Age Distribution
<65: 13, 65-74: 175, 75-84: 143, 85+: 42

Top Prescribed Drugs (Medicare Part D)

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

What CHARLES COFAS, 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
Levothyroxine Sodium
301
Atorvastatin Calcium
289
Amlodipine Besylate
261
Lisinopril
211
Losartan Potassium
152
Gabapentin
124
Hydrochlorothiazide
115
Simvastatin
115
Tamsulosin Hcl
111
Rosuvastatin Calcium
110

* 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 CHARLES COFAS, 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

CHARLES COFAS, M.D.'s 4,766 claims are above the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in Oregon

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

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

Frequently Asked Questions

What is CHARLES COFAS, M.D.'s specialty?
CHARLES COFAS, M.D. specializes in Internal Medicine Physician and practices in KLAMATH FALLS, Oregon. Credentials: M.D..
How much does CHARLES COFAS, M.D. prescribe under Medicare Part D?
In 2023, CHARLES COFAS, M.D. wrote 4,766 Medicare Part D claims totaling $370K in drug costs for 373 beneficiaries.
Where is CHARLES COFAS, M.D. located?
CHARLES COFAS, M.D. is located at 2640 BIEHN ST STE 4, KLAMATH FALLS, OR, 97601. Phone: (541) 882-3818.
What is CHARLES COFAS, M.D.'s NPI number?
CHARLES COFAS, M.D.'s National Provider Identifier (NPI) is 1053371666, issued on 03/27/2006.
Does CHARLES COFAS, M.D. prescribe more brand-name or generic drugs?
CHARLES COFAS, M.D.'s prescribing is 9% brand-name and 91% generic drugs by claim count, with $283K in brand drug costs.
Does CHARLES COFAS, M.D. prescribe opioids?
Yes, CHARLES COFAS, M.D. had 35 opioid claims in 2023 with an opioid prescribing rate of 0.7%.
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 CHARLES COFAS, M.D. prescribe most often?
Based on 2023 Medicare Part D data, CHARLES COFAS, M.D.'s most frequently prescribed drugs include Levothyroxine Sodium, Atorvastatin Calcium, Amlodipine Besylate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does CHARLES COFAS, M.D. accept Medicare?
CHARLES COFAS, M.D. appears in CMS Medicare data with 4,766 Part D claims and 373 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify CHARLES COFAS, M.D.'s credentials?
CHARLES COFAS, M.D.'s NPI is 1053371666 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