2026 NPPES data Internal Medicine Physician NPI 1427685270 MD
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KATHERINE ZITELLO, MD

Internal Medicine Physician in GREAT FALLS, Montana. 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
712
Medicare Part D claims · 124 beneficiaries · Internal Medicine Physician avg: 3K
Industry payments
$306.3
12 payments · CMS Open Payments (Sunshine Act)

What the federal data shows

KATHERINE ZITELLO, MD filed 712 Medicare Part D claims in 2023 as a Internal Medicine Physician in GREAT FALLS, Montana.

712
Part D claims, 2023
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.

KATHERINE ZITELLO, MD's Medicare Part D volume vs every U.S. prescriber

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

712 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)

KATHERINE ZITELLO, MD 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 KATHERINE ZITELLO, MD?

Quality data not reported

NPI registry status

Active

Issued 03/23/2020

NPI 1427685270

Primary specialty

Internal Medicine Physician

High-volume

172,858 US NPIs in this specialty

Medicare Part D claims

712 74% vs specialty avg

2023 prescription claims

Specialty avg: 2,716

Specialty distribution in Montana

How Internal Medicine Physician compares to other specialties among Montana providers

Montana providers

Internal Medicine Physician share within Montana

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

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).

KATHERINE ZITELLO, MD appears in the CMS NPPES registry as a Internal Medicine Physician provider holding MD credentials at 1401 25TH ST S, GREAT FALLS, MT, 59405, with a listed phone of (406) 731-8888. NPI 1427685270 was issued on 03/23/2020. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what ZITELLO 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 712 prescription claims written by this provider, covering 124 Medicare beneficiaries and totaling roughly $99K in drug spend. 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

1401 25TH ST S
GREAT FALLS, MT 59405

Provider Details

NPI 1427685270
Specialty Internal Medicine Physician
Credentials MD
Gender Female
NPI Issued 03/23/2020

Hospital and facility affiliations

Facilities where KATHERINE ZITELLO, MD 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.

BENEFIS HOSPITALS INC
★★☆☆☆ 2/5
GREAT FALLS, MT
Acute Care Hospitals
CMS CCN: 270012

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

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 KATHERINE ZITELLO, MD. Source: openpaymentsdata.cms.gov.

Total received

$306

Largest payer

AstraZeneca Pharmaceuticals LP

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.

Medicare Part D Prescribing Data

CMS Medicare Part D prescriber-level data for calendar year 2023.

712
Total Claims
$99K
Total Drug Cost
124
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
1,379
Total Day Supply
39,402
Generic Drug Cost
$13K
Antibiotic Claims
18

Patient Demographics

Average Patient Age
71.4 years
Avg HCC Risk Score
1.43
Gender Split
72% female / 28% male
Age Distribution
<65: 17, 65-74: 59, 75-84: 36, 85+: 12

Top Prescribed Drugs (Medicare Part D)

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

What KATHERINE ZITELLO, MD 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
45
Omeprazole
40
Amlodipine Besylate
29
Levothyroxine Sodium
29
Lisinopril
28
Duloxetine Hcl
24
Losartan Potassium
22
Januvia
Sitagliptin Phosphate
19
Gabapentin
18
Sertraline Hcl
17

* 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 KATHERINE ZITELLO, MD 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

KATHERINE ZITELLO, MD's 712 claims are below the specialty average of 2,716.

Nearby Internal Medicine Physician Providers in Montana

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

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

Frequently Asked Questions

What is KATHERINE ZITELLO, MD's specialty?
KATHERINE ZITELLO, MD specializes in Internal Medicine Physician and practices in GREAT FALLS, Montana. Credentials: MD.
How much does KATHERINE ZITELLO, MD prescribe under Medicare Part D?
In 2023, KATHERINE ZITELLO, MD wrote 712 Medicare Part D claims totaling $99K in drug costs for 124 beneficiaries.
Where is KATHERINE ZITELLO, MD located?
KATHERINE ZITELLO, MD is located at 1401 25TH ST S, GREAT FALLS, MT, 59405. Phone: (406) 731-8888.
What is KATHERINE ZITELLO, MD's NPI number?
KATHERINE ZITELLO, MD's National Provider Identifier (NPI) is 1427685270, issued on 03/23/2020.
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 KATHERINE ZITELLO, MD prescribe most often?
Based on 2023 Medicare Part D data, KATHERINE ZITELLO, MD's most frequently prescribed drugs include Atorvastatin Calcium, Omeprazole, Amlodipine Besylate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does KATHERINE ZITELLO, MD accept Medicare?
KATHERINE ZITELLO, MD appears in CMS Medicare data with 712 Part D claims and 124 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify KATHERINE ZITELLO, MD's credentials?
KATHERINE ZITELLO, MD's NPI is 1427685270 with credentials MD. 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