2026 NPPES data Optometrist NPI 1033341029 O.D.
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ISABEL ALONSO ZIEJA, O.D.

Optometrist in KITTERY, 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
90
Medicare Part D claims · 37 beneficiaries · Optometrist avg: 257
Generic prescribing
67%
generic claims · 33% brand-name · higher generic rates reduce patient out-of-pocket costs
MIPS score
99.5716/100
▲ 16 pts above national avg 83.1 · [object Object]
What the federal data reveals: ISABEL ALONSO ZIEJA, O.D. is a Optometrist ([object Object]) practicing in KITTERY, Maine with a Medicare Part D prescribing footprint of 90 claims across 37 beneficiaries — 33% brand-name prescribing . Their CMS MIPS Final Score of 99.5716/100 (national average: 83.1) reflects performance across Quality, Cost, Interoperability, and Improvement Activities .

What stands out: ISABEL ALONSO ZIEJA, O.D. reported a CMS MIPS final score of 99.5716 out of 100, above the 83.1 national average, and filed 90 Medicare Part D claims in 2023. Every figure on this page comes straight from federal CMS records, with no proprietary rating applied.

ISABEL ALONSO ZIEJA, O.D. at a glance

High performer (top quartile)

NPI registry status

Active

Issued 08/10/2009

NPI 1033341029

Primary specialty

Optometrist

High-volume

60,463 US NPIs in this specialty

Medicare Part D claims

90 65% vs specialty avg

2023 prescription claims

Specialty avg: 257

MIPS final score

99.5716/100 16.47160000000001% pts

Exceptional band

vs 83.1 national avg

Specialty distribution in Maine

How Optometrist compares to other specialties among Maine providers

Maine providers

Optometrist share within Maine

1. Optometrist42%2. Internal medicine21%3. Family medicine17%4. Surgical12%5. Pediatric8%
Optometrist share within Maine

Medicare quality performance — MIPS

ISABEL ALONSO ZIEJA, O.D.'s 2023 MIPS final score plotted against the Optometrist national average

High performer (top quartile)
MIPS Final Score
99.5716/100
vs 83.1 national avg · 2023 performance year

MIPS final score (Optometrist) — 99.5716/100 vs national avg 83.1

0%100%National avg83%99%
MIPS final score (Optometrist) — 99.5716/100 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).

ISABEL ALONSO ZIEJA, O.D. is a Optometrist provider practicing in KITTERY, Maine, according to the CMS National Plan and Provider Enumeration System (NPPES). Credentials: O.D.. NPI: 1033341029. This profile includes practice location, specialty classification, and organizational affiliations from the CMS provider registry. Provider information is self-reported to CMS and updated monthly.

ISABEL ALONSO ZIEJA, O.D. appears in the CMS NPPES registry as a Optometrist provider holding O.D. credentials at 99 US ROUTE 1 BYP, KITTERY, ME, 03904, with a listed phone of (207) 439-0410. NPI 1033341029 was issued on 08/10/2009. Because NPPES data is self-reported by the provider and refreshed monthly, the address, phone, and specialty reflect what ALONSO ZIEJA 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 90 prescription claims written by this provider, covering 37 Medicare beneficiaries and totaling roughly $25K in drug spend, split 33% brand-name and 67% 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 99.5716/100 for the 2023 performance year (Quality 99.1431), compared with the national average of 83.1.

Optometrist is a high-volume specialty nationwide, with 60,463 enrolled providers across 56 states and an average of 257 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

99 US ROUTE 1 BYP
KITTERY, ME 03904

Provider Details

NPI 1033341029
Specialty Optometrist
Credentials O.D.
Gender Female
NPI Issued 08/10/2009

CMS Quality Score (MIPS)

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

99.5716
Final Score
Avg: 83.1
99.1431
Quality

Reporting: Group practice

Hospital and facility affiliations

Facilities where ISABEL ALONSO ZIEJA, O.D. 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.

KITTERY OPTOMETRIC ASSOCIATES
KITTERY, 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

ISABEL ALONSO ZIEJA, O.D. — brand share 33.0%
Specialty average (est.)

33% brand-name claims vs 67% generic, on 90 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.

90
Total Claims
$25K
Total Drug Cost
37
Medicare Beneficiaries

Prescribing Breakdown

30-Day Fills
146
Total Day Supply
3,544
Brand vs Generic
33% brand / 67% generic
Brand Drug Cost
$23K
Generic Drug Cost
$2K

Patient Demographics

Average Patient Age
75.9 years
Avg HCC Risk Score
0.79

Top Prescribed Drugs (Medicare Part D)

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

Drug Claims
Latanoprost
39

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

Optometrist Overview

How ISABEL ALONSO ZIEJA, O.D. fits within the Optometrist landscape nationally.

60,463
Optometrist Providers in US
56
States with Optometrist
257
Avg Claims per Provider

ISABEL ALONSO ZIEJA, O.D.'s 90 claims are below the specialty average of 257.

Nearby Optometrist Providers in Maine

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

Compare Optometrist nationally: see state-by-state distribution →

Frequently Asked Questions

What is ISABEL ALONSO ZIEJA, O.D.'s specialty?
ISABEL ALONSO ZIEJA, O.D. specializes in Optometrist and practices in KITTERY, Maine. Credentials: O.D..
How much does ISABEL ALONSO ZIEJA, O.D. prescribe under Medicare Part D?
In 2023, ISABEL ALONSO ZIEJA, O.D. wrote 90 Medicare Part D claims totaling $25K in drug costs for 37 beneficiaries.
What is ISABEL ALONSO ZIEJA, O.D.'s Medicare quality score?
ISABEL ALONSO ZIEJA, O.D. has a CMS MIPS Final Score of 99.5716/100 (Quality: 99.1431). The national average MIPS Final Score is 83.1. Source: CMS Merit-based Incentive Payment System (MIPS) 2023.
Where is ISABEL ALONSO ZIEJA, O.D. located?
ISABEL ALONSO ZIEJA, O.D. is located at 99 US ROUTE 1 BYP, KITTERY, ME, 03904. Phone: (207) 439-0410.
What is ISABEL ALONSO ZIEJA, O.D.'s NPI number?
ISABEL ALONSO ZIEJA, O.D.'s National Provider Identifier (NPI) is 1033341029, issued on 08/10/2009.
Does ISABEL ALONSO ZIEJA, O.D. prescribe more brand-name or generic drugs?
ISABEL ALONSO ZIEJA, O.D.'s prescribing is 33% brand-name and 67% generic drugs by claim count, with $23K in brand drug costs.
How many Optometrist providers are there in the US?
There are 60,463 Optometrist providers across 56 states in the US. The average Optometrist provider writes 257 Medicare Part D claims per year.
What drugs does ISABEL ALONSO ZIEJA, O.D. prescribe most often?
Based on 2023 Medicare Part D data, ISABEL ALONSO ZIEJA, O.D.'s most frequently prescribed drugs include Latanoprost. This reflects Medicare Part D prescriptions only and does not include commercial insurance or other payer types.
Does ISABEL ALONSO ZIEJA, O.D. accept Medicare?
ISABEL ALONSO ZIEJA, O.D. appears in CMS Medicare data with 90 Part D claims and 37 Medicare beneficiaries in 2023. Contact the provider's office directly to confirm current Medicare enrollment and accepted plans.
How can I verify ISABEL ALONSO ZIEJA, O.D.'s credentials?
ISABEL ALONSO ZIEJA, O.D.'s NPI is 1033341029 with credentials O.D.. 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