2026 NPPES data Pediatrics Physician NPI 1922531326 MD
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CATHERINE DEFFENDALL, MD

Pediatrics Physician in NASHVILLE, 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
236
Medicare Part D claims · 44 beneficiaries · Pediatrics Physician avg: 762
Generic prescribing
71%
generic claims · 29% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

CATHERINE DEFFENDALL, MD filed 236 Medicare Part D claims in 2023 as a Pediatrics Physician in NASHVILLE, Tennessee, prescribing 71% generic.

236
Part D claims, 2023
71%
generic prescribing

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.

CATHERINE DEFFENDALL, MD's Medicare Part D volume vs every U.S. prescriber

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

236 49th percentile higher than 49% of 1,370,886 prescribers

0–200: 670,926 prescribers (49%). Below this entry. 200–400: 182,923 prescribers (13%). This entry sits in this band. 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-eligible specialty (heuristic — not verified)

CATHERINE DEFFENDALL, MD 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 CATHERINE DEFFENDALL, MD?

Quality data not reported

NPI registry status

Active

Issued 04/04/2017

NPI 1922531326

Primary specialty

Pediatrics Physician

High-volume

80,574 US NPIs in this specialty

Medicare Part D claims

236 69% vs specialty avg

2023 prescription claims

Specialty avg: 762

Specialty distribution in Tennessee

How Pediatrics Physician compares to other specialties among Tennessee providers

Tennessee providers

Pediatrics Physician share within Tennessee

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

Specialty board-certification context

Estimated specialty board-certified rate — Pediatrics Physician (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Pediatrics Physician ABMS/AOA estimate

Est. board-certified rate (Pediatrics Physician) — ABMS / AOA estimate

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

CATHERINE DEFFENDALL, MD appears in the CMS NPPES registry as a Pediatrics Physician provider holding MD credentials at 3601 THE VANDERBILT CLINIC, NASHVILLE, TN, 37232, with a listed phone of (615) 322-3000. NPI 1922531326 was issued on 04/04/2017. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what DEFFENDALL 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 236 prescription claims written by this provider, covering 44 Medicare beneficiaries and totaling roughly $435K in drug spend, split 29% brand-name and 71% 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.

Pediatrics Physician is a high-volume specialty nationwide, with 80,574 enrolled providers across 56 states and an average of 762 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

3601 THE VANDERBILT CLINIC
NASHVILLE, TN 37232

Provider Details

NPI 1922531326
Specialty Pediatrics Physician
Credentials MD
Gender Female
NPI Issued 04/04/2017

Brand vs generic prescribing mix · Above average

CATHERINE DEFFENDALL, MD — brand share 29.0%
Specialty average (est.)

29% brand-name claims vs 71% generic, on 236 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.

236
Total Claims
$435K
Total Drug Cost
44
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
431
Total Day Supply
12,743
Brand vs Generic
29% brand / 71% generic
Brand Drug Cost
$428K
Generic Drug Cost
$6K

Patient Demographics

Average Patient Age
61.6 years
Avg HCC Risk Score
1.99
Gender Split
66% female / 34% male
Age Distribution
<65: 20, 65-74: 18, 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 CATHERINE DEFFENDALL, 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
Methotrexate
Methotrexate Sodium
30
Prednisone
28
Allopurinol
18
Hydroxychloroquine Sulfate
18
Actemra
Tocilizumab
15
Enbrel Sureclick
Etanercept
15
Humira(Cf) Pen
Adalimumab
14

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

Pediatrics Physician Overview

How CATHERINE DEFFENDALL, MD fits within the Pediatrics Physician landscape nationally.

80,574
Pediatrics Physician Providers in US
56
States with Pediatrics Physician
762
Avg Claims per Provider

CATHERINE DEFFENDALL, MD's 236 claims are below the specialty average of 762.

Nearby Pediatrics Physician Providers in Tennessee

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

Compare Pediatrics Physician nationally: see state-by-state distribution →

Frequently Asked Questions

What is CATHERINE DEFFENDALL, MD's specialty?
CATHERINE DEFFENDALL, MD specializes in Pediatrics Physician and practices in NASHVILLE, Tennessee. Credentials: MD.
How much does CATHERINE DEFFENDALL, MD prescribe under Medicare Part D?
In 2023, CATHERINE DEFFENDALL, MD wrote 236 Medicare Part D claims totaling $435K in drug costs for 44 beneficiaries.
Where is CATHERINE DEFFENDALL, MD located?
CATHERINE DEFFENDALL, MD is located at 3601 THE VANDERBILT CLINIC, NASHVILLE, TN, 37232. Phone: (615) 322-3000.
What is CATHERINE DEFFENDALL, MD's NPI number?
CATHERINE DEFFENDALL, MD's National Provider Identifier (NPI) is 1922531326, issued on 04/04/2017.
Does CATHERINE DEFFENDALL, MD prescribe more brand-name or generic drugs?
CATHERINE DEFFENDALL, MD's prescribing is 29% brand-name and 71% generic drugs by claim count, with $428K in brand drug costs.
How many Pediatrics Physician providers are there in the US?
There are 80,574 Pediatrics Physician providers across 56 states in the US. The average Pediatrics Physician provider writes 762 Medicare Part D claims per year.
What drugs does CATHERINE DEFFENDALL, MD prescribe most often?
Based on 2023 Medicare Part D data, CATHERINE DEFFENDALL, MD's most frequently prescribed drugs include Methotrexate, Prednisone, Allopurinol. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does CATHERINE DEFFENDALL, MD accept Medicare?
CATHERINE DEFFENDALL, MD appears in CMS Medicare data with 236 Part D claims and 44 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify CATHERINE DEFFENDALL, MD's credentials?
CATHERINE DEFFENDALL, MD's NPI is 1922531326 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