John Kortenber, OD
NPI 1821049586 · Optometrist · Algona, IA
Enrolled with Medicare as Practitioner - Optometry · source: CMS PECOS Public Provider Enrollment (2026.04.01)
John Kortenber, OD is a Optometrist provider in Algona, IA (NPI 1821049586).
Provider details
- NPI number
- 1821049586
- Entity type
- Individual
- Primary specialty
- OptometristEye and Vision Services Providers
- Credential
- OD
- Sex
- Male
- Sole proprietor
- No
- License
- 2002014339 (MO)
Specialties & taxonomies
Eye and Vision Services Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
20 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)25% of score
554 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Problem Focused Exam of Visual System92012 | 285 | $82 |
| Imaging of Retina92134 | 55 | $36 |
| Imaging of Optic Nerve92133 | 49 | $31 |
| Exam of Visual Field With Extended Testing92083 | 48 | $57 |
| New Patient Problem Focused Exam of Visual System92002 | 47 | $78 |
| Removal of Cataract With Insertion of Prosthetic Lens66984 | 34 | $96 |
| Established Patient Complete Exam of Visual System |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 3 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Latanoprost | 218 | 55 |
| Timolol Maleate | 54 | 14 |
| Tobramycin/Dexamethasonebrand: Tobramycin-Dexamethasone | 13 | — |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$15 across 1 record (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-05-15
- Last updated
- 2023-03-07
Frequently asked questions
- What is John Kortenber's NPI number?
- John Kortenber's National Provider Identifier (NPI) is 1821049586, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is John Kortenber's specialty?
- John Kortenber is listed in the NPPES registry with a primary specialty of Optometrist (Eye and Vision Services Providers).
- Where is John Kortenber located?
- John Kortenber's practice location on file with NPPES is 112 N Thorington St, Algona, IA 50511-2614.
- What is John Kortenber's phone number?
- The practice phone number listed in the NPPES registry for John Kortenber is (515) 395-3937.
- Does John Kortenber accept Medicare?
- John Kortenber is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is John Kortenber's NPI active?
- Yes — John Kortenber's NPI (1821049586) is active in the NPPES registry as of the last update on 2023-03-07.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.