2026 NPPES data Nurse Practitioner NPI 1225439227 APNP
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CATHERINE DIAZ, APNP

Nurse Practitioner in MADISON, Wisconsin. 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
266
Medicare Part D claims · 51 beneficiaries · Nurse Practitioner avg: 1K
Generic prescribing
84%
generic claims · 16% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
77.4384/100
▼ 6 pts below national avg 83.1 · [object Object]

What the federal data shows

CATHERINE DIAZ, APNP reported a CMS MIPS final score of 77.4384/100 — below the 83.1 national average — and filed 266 Medicare Part D claims in 2023.

77.4384/100
MIPS score · -6 vs avg
266
Part D claims, 2023
84%
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 DIAZ, APNP's MIPS score vs every scored U.S. clinician

CMS Merit-based Incentive Payment System (MIPS) final score, 2023 — the federal quality measure

77 24th percentile higher than 24% of 477,587 scored providers

0–10: 8,684 scored providers (2%). Below this entry. 10–20: 3,008 scored providers (1%). Below this entry. 20–30: 3,069 scored providers (1%). Below this entry. 30–40: 2,746 scored providers (1%). Below this entry. 40–50: 2,928 scored providers (1%). Below this entry. 50–60: 5,882 scored providers (1%). Below this entry. 60–70: 13,906 scored providers (3%). Below this entry. 70–80: 118,074 scored providers (25%). This entry sits in this band. 80–90: 129,887 scored providers (27%). Above this entry. 90–100: 189,403 scored providers (40%). Above this entry. This provider 0 100 every MIPS-scored clinician, bucketed by value

Each bar is a band; taller bars hold more scored providers. 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 Merit-based Incentive Payment System (MIPS) · 2023

What does the federal data show about CATHERINE DIAZ, APNP?

Below national average

NPI registry status

Active

Issued 09/09/2014

NPI 1225439227

Primary specialty

Nurse Practitioner

High-volume

87,227 US NPIs in this specialty

Medicare Part D claims

266 75% vs specialty avg

2023 prescription claims

Specialty avg: 1,084

MIPS final score

77.4384/100 5.661599999999993% pts

Above neutral band

vs 83.1 national avg

Specialty distribution in Wisconsin

How Nurse Practitioner compares to other specialties among Wisconsin providers

Wisconsin providers

Nurse Practitioner share within Wisconsin

1. Nurse Practitioner42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Nurse Practitioner share within Wisconsin

Medicare quality performance — MIPS

CATHERINE DIAZ, APNP's 2023 MIPS final score plotted against the Nurse Practitioner national average

Below national average
MIPS Final Score
77.4384/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Nurse Practitioner) — 77.4384/100 vs national avg 83.1

0%100%National avg83%77.4%
MIPS final score (Nurse Practitioner) — 77.4384/100 vs national avg 83.1

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 DIAZ, APNP appears in the CMS NPPES registry as a Nurse Practitioner provider holding APNP credentials at 2601 W BELTLINE HWY, MADISON, WI, 53713, with a listed phone of (608) 417-2193. NPI 1225439227 was issued on 09/09/2014. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what DIAZ 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 266 prescription claims written by this provider, covering 51 Medicare beneficiaries and totaling roughly $35K in drug spend, split 16% brand-name and 84% 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. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 77.4384/100 for the 2023 performance year (Quality 81.8371, Cost 62.1241), compared with the national average of 83.1.

Nurse Practitioner is a high-volume specialty nationwide, with 87,227 enrolled providers across 56 states and an average of 1,084 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

2601 W BELTLINE HWY
MADISON, WI 53713

Provider Details

NPI 1225439227
Specialty Nurse Practitioner
Credentials APNP
Gender Female
NPI Issued 09/09/2014

CMS Quality Score (MIPS)

Merit-based Incentive Payment System (MIPS) scores from CMS, 2023 performance year.

77.4384
Final Score
Avg: 83.1
81.8371
Quality
62.1241
Cost
77
Promoting Interoperability

Reporting: Group practice

Hospital and facility affiliations

Facilities where CATHERINE DIAZ, APNP 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.

UNIVERSITY OF WISCONSIN MEDICAL FOUNDATION INC
MADISON, WI

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 · Typical

CATHERINE DIAZ, APNP — brand share 16.0%
Specialty average (est.)

16% brand-name claims vs 84% generic, on 266 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.

266
Total Claims
$35K
Total Drug Cost
51
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
415
Total Day Supply
11,965
Brand vs Generic
16% brand / 84% generic
Brand Drug Cost
$31K
Generic Drug Cost
$4K

Patient Demographics

Average Patient Age
74.9 years
Avg HCC Risk Score
1.53
Gender Split
45% female / 55% male

Top Prescribed Drugs (Medicare Part D)

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

What CATHERINE DIAZ, APNP 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
Furosemide
22
Sertraline Hcl
22
Metoprolol Succinate
21
Amlodipine Besylate
18
Atorvastatin Calcium
17
Eliquis
Apixaban
16
Gabapentin
13
Potassium Chloride
13

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

Nurse Practitioner Overview

How CATHERINE DIAZ, APNP fits within the Nurse Practitioner landscape nationally.

87,227
Nurse Practitioner Providers in US
56
States with Nurse Practitioner
1,084
Avg Claims per Provider

CATHERINE DIAZ, APNP's 266 claims are below the specialty average of 1,084.

Nearby Nurse Practitioner Providers in Wisconsin

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

Compare Nurse Practitioner nationally: see state-by-state distribution →

Frequently Asked Questions

What is CATHERINE DIAZ, APNP's specialty?
CATHERINE DIAZ, APNP specializes in Nurse Practitioner and practices in MADISON, Wisconsin. Credentials: APNP.
How much does CATHERINE DIAZ, APNP prescribe under Medicare Part D?
In 2023, CATHERINE DIAZ, APNP wrote 266 Medicare Part D claims totaling $35K in drug costs for 51 beneficiaries.
What is CATHERINE DIAZ, APNP's Medicare quality score?
CATHERINE DIAZ, APNP has a CMS MIPS Final Score of 77.4384/100 (Quality: 81.8371, Cost: 62.1241). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is CATHERINE DIAZ, APNP located?
CATHERINE DIAZ, APNP is located at 2601 W BELTLINE HWY, MADISON, WI, 53713. Phone: (608) 417-2193.
What is CATHERINE DIAZ, APNP's NPI number?
CATHERINE DIAZ, APNP's National Provider Identifier (NPI) is 1225439227, issued on 09/09/2014.
Does CATHERINE DIAZ, APNP prescribe more brand-name or generic drugs?
CATHERINE DIAZ, APNP's prescribing is 16% brand-name and 84% generic drugs by claim count, with $31K in brand drug costs.
How many Nurse Practitioner providers are there in the US?
There are 87,227 Nurse Practitioner providers across 56 states in the US. The average Nurse Practitioner provider writes 1,084 Medicare Part D claims per year.
What drugs does CATHERINE DIAZ, APNP prescribe most often?
Based on 2023 Medicare Part D data, CATHERINE DIAZ, APNP's most frequently prescribed drugs include Furosemide, Sertraline Hcl, Metoprolol Succinate. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does CATHERINE DIAZ, APNP accept Medicare?
CATHERINE DIAZ, APNP appears in CMS Medicare data with 266 Part D claims and 51 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify CATHERINE DIAZ, APNP's credentials?
CATHERINE DIAZ, APNP's NPI is 1225439227 with credentials APNP. 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.
Quality Performance
CMS Merit-based Incentive Payment System (MIPS) — 2023 performance year.
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