2026 NPPES data Family Nurse Practitioner NPI 1265611537 APRN
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Gertrude Oster, APRN

Family Nurse Practitioner in Tucson, Arizona. 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
156
Medicare Part D claims · 39 beneficiaries · Family Nurse Practitioner avg: 1K
Generic prescribing
74%
generic claims · 26% brand-name · higher generic rates reduce patient out-of-pocket costs

What the federal data shows

Gertrude Oster, APRN filed 156 Medicare Part D claims in 2023 as a Family Nurse Practitioner in Tucson, Arizona, prescribing 74% generic.

156
Part D claims, 2023
74%
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.

Gertrude Oster, APRN's Medicare Part D volume vs every U.S. prescriber

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

156 35th percentile higher than 35% 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

What does the federal data show about Gertrude Oster, APRN?

Quality data not reported

NPI registry status

Active

Issued 11/02/2007

NPI 1265611537

Primary specialty

Family Nurse Practitioner

High-volume

209,817 US NPIs in this specialty

Medicare Part D claims

156 87% vs specialty avg

2023 prescription claims

Specialty avg: 1,222

Specialty distribution in Arizona

How Family Nurse Practitioner compares to other specialties among Arizona providers

Arizona providers

Family Nurse Practitioner share within Arizona

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

Specialty board-certification context

Estimated specialty board-certified rate — Family Nurse Practitioner (ABMS / AOA reference)

Quality data not reported
Est. board-certified rate
78%
Family Nurse Practitioner ABMS/AOA estimate

Est. board-certified rate (Family Nurse Practitioner) — ABMS / AOA estimate

0%100%78%
Est. board-certified rate (Family Nurse Practitioner) — 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).

Gertrude Oster, APRN appears in the CMS NPPES registry as a Family Nurse Practitioner provider holding APRN credentials at 4511 N CAMPBELL AVE STE 100, Tucson, AZ, 85718, with a listed phone of (520) 529-6500. NPI 1265611537 was issued on 11/02/2007. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what Oster 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 156 prescription claims written by this provider, covering 39 Medicare beneficiaries and totaling roughly $35K in drug spend, split 26% brand-name and 74% 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.

Family Nurse Practitioner is a high-volume specialty nationwide, with 209,817 enrolled providers across 56 states and an average of 1,222 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

4511 N CAMPBELL AVE STE 100
Tucson, AZ 85718

Provider Details

NPI 1265611537
Specialty Family Nurse Practitioner
Credentials APRN
Gender Female
NPI Issued 11/02/2007

Hospital and facility affiliations

Facilities where Gertrude Oster, APRN 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.

Akdhc LLC
Kingman, AZ

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

Gertrude Oster, APRN — brand share 26.0%
Specialty average (est.)

26% brand-name claims vs 74% generic, on 156 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.

156
Total Claims
$35K
Total Drug Cost
39
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
249
Total Day Supply
7,301
Brand vs Generic
26% brand / 74% generic
Brand Drug Cost
$30K
Generic Drug Cost
$4K

Patient Demographics

Average Patient Age
60.9 years
Avg HCC Risk Score
9.99
Gender Split
41% female / 59% male
Age Distribution
<65: 23, 65-74: N/A, 75-84: N/A, 85+: 0

Top Prescribed Drugs (Medicare Part D)

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

What Gertrude Oster, APRN 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
Calcium Acetate
20
Furosemide
18
Hydralazine Hcl
15
Lidocaine-Prilocaine
Lidocaine/Prilocaine
14

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

Family Nurse Practitioner Overview

How Gertrude Oster, APRN fits within the Family Nurse Practitioner landscape nationally.

209,817
Family Nurse Practitioner Providers in US
56
States with Family Nurse Practitioner
1,222
Avg Claims per Provider

Gertrude Oster, APRN's 156 claims are below the specialty average of 1,222.

Nearby Family Nurse Practitioner Providers in Arizona

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

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

Before you book an appointment

Use this federal record as your verification checklist, not as a recommendation.

  • Confirm the NPI record is current in the official CMS registry — providers update their own NPPES details, and moves can lag. Verify this NPI
  • Check the active license and any disciplinary history with the Arizona medical board — federal registration is not a license check. Credential verification guide
  • Weigh a second option: compare this provider with a nearby Family Nurse Practitioner peer on Medicare volume and prescribing patterns. Compare providers

Medicare Part D and MIPS figures describe practice patterns in federal programs only — they are not quality ratings, and PlainDoctor does not rate, rank, or recommend providers.

Frequently Asked Questions

What is Gertrude Oster, APRN's specialty?
Gertrude Oster, APRN specializes in Family Nurse Practitioner and practices in Tucson, Arizona. Credentials: APRN.
How much does Gertrude Oster, APRN prescribe under Medicare Part D?
In 2023, Gertrude Oster, APRN wrote 156 Medicare Part D claims totaling $35K in drug costs for 39 beneficiaries.
Where is Gertrude Oster, APRN located?
Gertrude Oster, APRN is located at 4511 N CAMPBELL AVE STE 100, Tucson, AZ, 85718. Phone: (520) 529-6500.
What is Gertrude Oster, APRN's NPI number?
Gertrude Oster, APRN's National Provider Identifier (NPI) is 1265611537, issued on 11/02/2007.
Does Gertrude Oster, APRN prescribe more brand-name or generic drugs?
Gertrude Oster, APRN's prescribing is 26% brand-name and 74% generic drugs by claim count, with $30K in brand drug costs.
How many Family Nurse Practitioner providers are there in the US?
There are 209,817 Family Nurse Practitioner providers across 56 states in the US. The average Family Nurse Practitioner provider writes 1,222 Medicare Part D claims per year.
What drugs does Gertrude Oster, APRN prescribe most often?
Based on 2023 Medicare Part D data, Gertrude Oster, APRN's most frequently prescribed drugs include Calcium Acetate, Furosemide, Hydralazine Hcl. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does Gertrude Oster, APRN accept Medicare?
Gertrude Oster, APRN appears in CMS Medicare data with 156 Part D claims and 39 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify Gertrude Oster, APRN's credentials?
Gertrude Oster, APRN's NPI is 1265611537 with credentials APRN. 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