NPI registry status
Active
2026 NPPES data Optometrist NPI 1033341029 O.D.
Verify on CMS → Isabel Alonso Zieja, O.D.
Optometrist in Kittery, Maine.
This profile is drawn from the federal National Provider Identifier Registry (CMS NPPES), which lists more than 7 million U.S. healthcare providers - including 60,463 in Optometrist, and covers specialty classification, practice address, and Medicare Part D prescribing data when reported. According to CMS, every field reflects the provider's official federal registration, see our methodology.
Federal data, no proprietary rating.
We show these CMS records as-is - no composite score, no star rating, no editorial opinion layered on top.
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
99.6/100
▲ 16 pts above national avg 83.1 · Exceptional
Source: CMS Medicare Part D Prescriber Public Use File, 2023
Compiled from official public sources by the PlainDoctor editorial team.
What the federal data shows
Isabel Alonso Zieja, O.D. reported a CMS MIPS final score of 99.6/100 - above the 83.1 national average - and filed 90 Medicare Part D claims in 2023.
- 99.6/100
- MIPS score · +16 vs avg
- 90
- Part D claims, 2023
- 67%
- 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.
Isabel Alonso Zieja, O.D.'s MIPS score vs every scored U.S. clinician
CMS Merit-based Incentive Payment System (MIPS) final score, 2023, the federal quality measure
100 Top 9% higher than 91% of 477,587 scored providers
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
Where Isabel Alonso Zieja, O.D. sits
This provider among optometrist peers
Across the 6,527 optometrist providers who report both Medicare Part D prescribing and a MIPS quality score, Isabel Alonso Zieja, O.D. writes more Part D claims than 17% of them and scores higher on MIPS quality than 90% - placing this provider in the lower-volume, high-quality quadrant. Volume reflects patient-panel size and specialty, not quality; the two axes are independent.
Part D claim volume vs MIPS quality, by specialty percentile
Each dot is one optometrist peer from a representative sample of 60; the gold marker is Isabel Alonso Zieja, O.D.. Source: CMS Medicare Part D Prescriber data and the CMS Merit-based Incentive Payment System, 2023.
What does the federal data show about Isabel Alonso Zieja, O.D.?
High performer (top quartile)Primary specialty
Optometrist
Medicare Part D claims
90 65% vs specialty avg
MIPS final score
99.6/100 16.5 pts vs avg
Specialty distribution in Maine
How Optometrist compares to other specialties among Maine providers
Medicare quality performance, MIPS
Isabel Alonso Zieja, O.D.'s 2023 MIPS final score plotted against the Optometrist national average
- MIPS Final Score
- 99.6/100
- vs 83.1 national avg · 2023 performance year
MIPS final score (Optometrist) - 99.6/100 vs national avg 83.1
How MIPS and board certification work
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. 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.
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. On the CMS Merit-based Incentive Payment System, this provider earned a Final Score of 99.6/100 for the 2023 performance year (Quality 99.1), 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
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%
Optometrist average
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.
Dr. Amy Abbott
O.D.
South Portland, ME
Dr. Andre Achenbach
O.D.
Brunswick, ME
Dr. Rachel Achenbach
OD
Windham, ME
Dr. Nirupama Aggarwal
OD
Portland, ME
Dr. Paul Albert
O.D.
Ellsworth, ME
Compare Optometrist 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 Maine medical board, federal registration is not a license check. Credential verification guide
- Weigh a second option: compare this provider with a nearby Optometrist 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.
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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 99.6/100 (Quality: 99.1). 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
View source datasets and methodology notes
- 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
Compiled from official public sources by the PlainDoctor editorial team.