2026 NPPES data Critical Care Medicine (Internal Medicine) Physician NPI 1689109423
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KATHRYN LIBBY

Critical Care Medicine (Internal Medicine) Physician in SOUTH PORTLAND, Maine. 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
47
Medicare Part D claims · 13 beneficiaries · Critical Care Medicine (Internal Medicine) Physician avg: 1K
Generic prescribing
55%
generic claims · 45% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

KATHRYN LIBBY filed 47 Medicare Part D claims in 2023 as a Critical Care Medicine (Internal Medicine) Physician in SOUTH PORTLAND, Maine, prescribing 55% generic.

47
Part D claims, 2023
55%
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.

KATHRYN LIBBY's Medicare Part D volume vs every U.S. prescriber

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

47 0th percentile higher than 0% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). This entry sits in this band. 200–400: 182,923 prescribers (13%). Above this entry. 400–600: 90,619 prescribers (7%). Above this entry. 600–800: 56,224 prescribers (4%). Above this entry. 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)

KATHRYN LIBBY practices in an ABMS-board-eligible specialty and shows active CMS Medicare participation + 3 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 KATHRYN LIBBY?

Quality data not reported

NPI registry status

Active

Issued 05/01/2017

NPI 1689109423

Primary specialty

Critical Care Medicine (Internal Medicine) Physician

Mid-sized

6,631 US NPIs in this specialty

Medicare Part D claims

47 96% vs specialty avg

2023 prescription claims

Specialty avg: 1,069

Specialty distribution in Maine

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

Maine providers

Critical Care Medicine (Internal Medicine) Physician share within Maine

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 Maine

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).

KATHRYN LIBBY appears in the CMS NPPES registry as a Critical Care Medicine (Internal Medicine) Physician provider at 100 FODEN RD STE 103, SOUTH PORTLAND, ME, 04106, with a listed phone of (207) 828-1122. NPI 1689109423 was issued on 05/01/2017. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what LIBBY 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 47 prescription claims written by this provider, covering 13 Medicare beneficiaries and totaling roughly $22K in drug spend, split 45% brand-name and 55% 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

100 FODEN RD STE 103
SOUTH PORTLAND, ME 04106

Provider Details

NPI 1689109423
Specialty Critical Care Medicine (Internal Medicine) Physician
Gender Female
NPI Issued 05/01/2017

Hospital and facility affiliations

Facilities where KATHRYN LIBBY 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.

CHEST MEDICINE ASSOCIATES PA
SOUTH PORTLAND, ME
MAINEHEALTH
LIVERMORE FALLS, ME
MERCY HOSPITAL
PORTLAND, ME

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

KATHRYN LIBBY — brand share 45.0%
Specialty average (est.)

45% brand-name claims vs 55% generic, on 47 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.

47
Total Claims
$22K
Total Drug Cost
13
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
61
Total Day Supply
1,752
Brand vs Generic
45% brand / 55% generic
Brand Drug Cost
$14K
Generic Drug Cost
$8K

Patient Demographics

Average Patient Age
62.7 years
Avg HCC Risk Score
2.02

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Trelegy Ellipta
Fluticasone/Umeclidin/Vilanter
13
Montelukast Sodium
11

* 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 KATHRYN LIBBY 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

KATHRYN LIBBY's 47 claims are below the specialty average of 1,069.

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

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

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

Frequently Asked Questions

What is KATHRYN LIBBY's specialty?
KATHRYN LIBBY specializes in Critical Care Medicine (Internal Medicine) Physician and practices in SOUTH PORTLAND, Maine.
How much does KATHRYN LIBBY prescribe under Medicare Part D?
In 2023, KATHRYN LIBBY wrote 47 Medicare Part D claims totaling $22K in drug costs for 13 beneficiaries.
Where is KATHRYN LIBBY located?
KATHRYN LIBBY is located at 100 FODEN RD STE 103, SOUTH PORTLAND, ME, 04106. Phone: (207) 828-1122.
What is KATHRYN LIBBY's NPI number?
KATHRYN LIBBY's National Provider Identifier (NPI) is 1689109423, issued on 05/01/2017.
Does KATHRYN LIBBY prescribe more brand-name or generic drugs?
KATHRYN LIBBY's prescribing is 45% brand-name and 55% generic drugs by claim count, with $14K 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 KATHRYN LIBBY prescribe most often?
Based on 2023 Medicare Part D data, KATHRYN LIBBY's most frequently prescribed drugs include Trelegy Ellipta, Montelukast Sodium. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does KATHRYN LIBBY accept Medicare?
KATHRYN LIBBY appears in CMS Medicare data with 47 Part D claims and 13 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify KATHRYN LIBBY's credentials?
KATHRYN LIBBY's NPI is 1689109423. 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