CHARLES EARL AHRENS M.D.
NPI 1356540827
Ophthalmology in Duluth, MN

Q: What is Charles Ahrens's NPI number?

The NPI number for Charles Ahrens is 1356540827. It was assigned to this individual provider in the NPPES registry on July 16, 2007.

Q: What is Charles Ahrens's specialty?

The primary specialty registered for this NPI is Ophthalmology with taxonomy code 207W00000X.

Q: When was this NPI record last updated?

The NPPES record for Charles Ahrens was last updated on December 4, 2020. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 5 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.

Active since July 16, 2007PECOS EnrolledAccepts Medicare Assignment

4190 LOBERG AVE, DULUTH, MN 55811(218) 249-4600(218) 249-4666 Get Directions Write a Review

NPPES record last updated: December 4, 2020. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Dec 4, 2020, Feb 7, 2017 (2 updates tracked since 2017).

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About Charles Earl Ahrens M.d. NPPES

Official registry information on file with the National Plan and Provider Enumeration System.

CHARLES EARL AHRENS M.D. (NPI 1356540827) is an individual ophthalmology provider in Duluth, Minnesota, licensed in Minnesota (53850) and active in the NPI registry since July 2007. He is enrolled in Medicare PECOS, is affiliated with St Lukes Hospital, and is a graduate of Sanford School Of Medicine Of University Of South Dakota (2007).

NPPES Registry Identity

NPI1356540827

Entity TypeIndividualMale

Primary Taxonomy207W00000X

Provider Legal NameCHARLES EARL AHRENSCredential: M.D.

Location Address4190 LOBERG AVEDuluth, MN 55811-2652

Mailing Address4190 Loberg AveDuluth, MN 55811-2652 · (218) 249-4600 · Fax (218) 249-4666

Phone(218) 249-4600

Fax(218) 249-4666

Sole ProprietorNo

Medical School CMSSanford School Of Medicine Of University Of South DakotaGraduated 2007

Enumeration DateJuly 16, 2007

Last NPPES UpdateDecember 4, 20202 updates tracked since enumeration

NPPES CertifiedDecember 4, 2020

✔ NPI 1356540827 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyOphthalmologyAllopathic & Osteopathic Physicians

Taxonomy Code207W00000X

License✔ Licensed in MN · 53850

Definition

An ophthalmologist has the knowledge and professional skills needed to provide comprehensive eye and vision care. Ophthalmologists are medically trained to diagnose, monitor and medically or surgically treat all ocular and visual disorders. This includes problems affecting the eye and its component structures, the eyelids, the orbit and the visual pathways. In so doing, an ophthalmologist prescribes vision services, including glasses and contact lenses.

4190 LOBERG AVE, Duluth, MN 55811

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Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Anthem Blue Cross and Blue Shield, Aspirus Health Plan, HealthPartners and more.Insurance ›

Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare and accepts Medicare assignment

Charles Earl Ahrens M.d. is registered in PECOS and agrees to accept the Medicare-approved amount as full payment. Medicare patients are not billed beyond the standard deductible and coinsurance.

PECOS PAC ID8921279381

PECOS Enrollment IDI20110915000829

Eligible to Order & Refer✔ Part B Labs & Imaging✔ Durable Medical Equipment✔ Home Health Agency✔ Power Mobility DevicesPer the CMS Ordering and Referring file. Eligibility means Medicare pays claims that this provider orders or refers for these categories.

Medicare Billing Reassignment

Medicare enrollment records show Charles Ahrens reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

St. Luke's Hospital Of Duluth

Same address

Family Medicine

4190 LOBERG AVE
Duluth, MN 55811

Reassigned Medicare billing, Minnesota enrollment
513 clinicians in this Medicare group

NPI 1609828029 (218) 249-4600

Source: CMS Revalidation Reassignment List, October 2026 release. Reassignment records can lag staffing changes; confirm a current affiliation with the organization.

Areas of Expertise CMS Part B claims 14

Services this provider delivered to Medicare fee-for-service patients, from the CMS Medicare utilization data. Higher counts generally reflect more experience with a service; care delivered outside Medicare is not included.

Imaging of retina 92134

Imaging of the retina is a non-invasive procedure that captures detailed images of your eye's interior. This helps detect conditions like macular degeneration or retinal detachment. It's painless and takes only a few minutes.

359 services94 patients

Established patient complete exam of visual system 92014

An established patient complete exam of the visual system involves a thorough check of your eyes and vision. It assesses eye health, checks for diseases, and measures your ability to see clearly at different distances. It's a routine, non-invasive procedure.

270 services269 patients

Injection of drug into eye 67028

An injection into the eye is a procedure where a medication is delivered directly into your eye to treat various conditions. A local anesthetic is applied to numb the eye, ensuring minimal discomfort. The drug helps manage diseases like macular degeneration or diabetic retinopathy.

255 services43 patients

Established patient office or other outpatient visit with low level od decision making, if using time, 20 minutes or more 99213

This is a routine visit for patients who have already been seen by the healthcare provider. During this approximately 20-29 minute appointment, your health status will be evaluated and any necessary treatments or tests will be discussed. It's a chance to address any health concerns you may have.

239 services129 patients

Measurement of corneal curvature and depth of eye 92136

This procedure measures the shape and depth of your eye, specifically the cornea, the clear front surface. It helps in diagnosing conditions, planning for surgeries, or fitting contact lenses. It's non-invasive and painless.

113 services62 patients

Removal of cataract with insertion of prosthetic lens 66984

This is a procedure where a cloudy lens in your eye, known as a cataract, is removed. After removal, a clear artificial lens is inserted. This helps to restore your vision, enabling you to see clearly again.

103 services61 patients

Established patient office or other outpatient visit with moderate level of decision making, if using time, 30 minutes or more 99214

This is a routine check-up for patients who have previously visited our clinic. It involves a comprehensive review of your health and any ongoing treatments. The consultation lasts between 30-39 minutes, allowing enough time to discuss any concerns.

83 services78 patients

Exam of visual field with extended testing 92083

An extended visual field exam is a detailed test to evaluate your peripheral (side) vision. It helps to detect any potential blind spots which may not be noticeable in daily life. These could be caused by eye diseases like glaucoma, or neurological conditions.

47 services46 patients

New patient office or other outpatient visit with moderate level of medical decision making, if using time, 45 minutes or more 99204

This is a first-time office or outpatient visit lasting between 45-59 minutes. The healthcare provider evaluates your health, discusses your medical history, and may suggest further tests or treatments. It's an opportunity to ask questions and understand your health better.

47 services47 patients

Injection, bevacizumab, 10 mg J9035

Bevacizumab is a medication given through an injection. It's designed to prevent the growth of new blood vessels that cancer cells need to grow and spread. The 10 mg dose refers to the amount of the drug in the injection.

42 services11 patients

Imaging of optic nerve 92133

Imaging of the optic nerve is a non-invasive procedure that captures detailed pictures of your optic nerve. It helps doctors assess eye health, particularly for conditions like glaucoma. It's painless, quick, and uses safe technology like MRI or OCT (Optical Coherence Tomography).

36 services36 patients

New patient complete exam of visual system 92004

A new patient complete exam of the visual system is a thorough evaluation of your eyes and vision. It checks for any potential issues and assesses overall eye health. It includes tests for visual acuity, eye movement, and light response.

26 services26 patients

Removal of recurring cataract in lens capsule using a laser 66821

This procedure, known as YAG laser capsulotomy, treats cloudiness in the lens capsule following cataract surgery. A laser is used to create a small hole in the cloudy capsule, allowing light to pass through and restore clear vision. It's a quick, painless procedure.

21 services17 patients

Ct scan of cornea 92025

A CT scan of the cornea is a non-invasive imaging test that uses X-rays to capture detailed pictures of your eye's cornea. It helps in diagnosing diseases or damage, planning for surgery, or evaluating the results of a treatment. It's a safe and painless procedure.

11 services11 patients

Hospital Affiliations CMS Care Compare

Hospitals where this provider delivers care, identified from recent Medicare claims and place-of-service records.

St Lukes Hospital

Acute Care Hospitals · Duluth, MN

3/5 CMS rating

OwnershipVoluntary non-profit - Private

CMS Certification Number240047

Location915 East 1st StreetDuluth, MN 55805 · St. Louis County

Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 55811 ZIP code area, from fee-for-service claims. These are area statistics, not this provider’s prices; actual charges vary by service and coverage.

New Patient

$127.61 typical visit price

range $56.00 – $168.28

Typical copayment $31.90 (range $14.00 – $42.07)

Most-billed visit code 99204

Established Patient

$69.74 typical visit price

range $18.32 – $138.04

Typical copayment $17.43 (range $4.58 – $34.51)

Most-billed visit code 99213

Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Other Providers at the Same Location NPPES 17

Providers registered at the same practice address, or within the immediate area, according to the NPPES registry.

LAUREN WALLACE MD

Family Medicine

4190 LOBERG AVE
DULUTH, MN 55811

St. Louis County (218) 249-4600

NICOLE COLLISON DPT

Physical Therapist

4190 LOBERG AVE
HERMANTOWN, MN 55811

St. Louis County (218) 249-6040

DR. ELIZABETH A LILJEBLAD MD

Family Medicine

4190 LOBERG AVE
HERMANTOWN, MN 55811

St. Louis County (218) 249-4600

DR. GERARD DAVID SPOELHOF M.D.

Family Medicine

4190 LOBERG AVE
DULUTH, MN 55811

St. Louis County (218) 249-5700

BENJAMIN H JOHNSON MD

Family Medicine

4190 LOBERG AVE
DULUTH, MN 55811

St. Louis County (218) 249-5700

MADELYN SODERBERG

Physical Therapist

4190 LOBERG AVE
HERMANTOWN, MN 55811

St. Louis County (218) 249-5700

MATTHEW GRANT PENNING M.D.

Family Medicine

4190 LOBERG AVE
DULUTH, MN 55811

St. Louis County (218) 249-5700

DR. JAMES Q. DONOVAN MD

Family Medicine

4190 LOBERG AVE
DULUTH, MN 55811

St. Louis County (218) 249-4600

Frequently Asked Questions NPPES & CMS

Common questions about this NPI record, answered from the official NPPES registry and CMS datasets shown on this page.

What is Charles Ahrens's NPI number?

The NPI number for Charles Ahrens is 1356540827. It was assigned to this individual provider in the NPPES registry on July 16, 2007.

Where is Charles Ahrens located?

Charles Ahrens practices at 4190 Loberg Ave, Duluth, MN 55811. The listed phone number is (218) 249-4600.

What is Charles Ahrens's specialty?

The primary specialty registered for this NPI is Ophthalmology with taxonomy code 207W00000X.

Is Charles Ahrens enrolled in Medicare?

Yes. Charles Ahrens is registered in the Medicare PECOS system and accepts Medicare assignment, which means accepting the Medicare-approved amount as payment in full for covered services.

Which organization bills Medicare for Charles Ahrens's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Charles Ahrens reassigns Medicare benefits to St. Luke's Hospital Of Duluth (Duluth, MN). The reassignment is filed with Medicare on form CMS-855R, signed by both the clinician and the organization, and lets the organization bill Medicare and receive payment for Charles Ahrens's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Charles Ahrens accept?

Health plans from Anthem Blue Cross and Blue Shield, Aspirus Health Plan, HealthPartners and Security Health Plan list Charles Ahrens as in-network in at least one marketplace plan. Coverage varies by plan and year; verify with the insurer or the provider before a visit.

Is Charles Ahrens affiliated with any hospitals?

According to CMS data, Charles Ahrens is affiliated with St Lukes Hospital.

When was this NPI record last updated?

The NPPES record for Charles Ahrens was last updated on December 4, 2020. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 5 years ago. If this record has changed at CMS more recently, you can request an on-demand re-check against the live CMS registry, directly from this page.