Diane Jean Ernst , ARNP
Nurse Practitioner • Decorah, IA
901 Montgomery St
Decorah, IA 521012325
This profile restates public CMS/NPPES data; T-MedInfo gives no medical advice — consult a licensed professional, and call 911 for emergencies.
Practice Location & Contact Primary Location
901 Montgomery St
Decorah, IA 521012325
Matched by practice address or phone in NPPES. A shared address or phone does not confirm that this clinician works there.
What Public CMS Data Show
Nurse Practitioner: NPPES taxonomy is a reported classification, not proof of board certification.
Industry payments (Open Payments)
No Open Payments records are listed for this clinician for 2021–2025.
NPI first issued
2006
The year this clinician's National Provider Identifier (NPI) was issued. An NPI is a unique 10-digit ID that US health care providers use for billing.
What this does not show: NPI first issued
NPIs have been issued only since 2005, so this year is not necessarily when the clinician started practicing.
Source: CMS NPPES NPI Registry.
Medicare assignment not listed
CMS data do not show whether this clinician accepts Medicare assignment. This does not mean they do not accept Medicare. Ask the office.
Medicare assignment applies to Original Medicare. It does not tell you whether the clinician is in a Medicare Advantage plan's network, accepts other insurance, or is taking new patients.
Source: CMS Doctors and Clinicians, CMS release of October 2, 2026; Medicare.gov, “Does your provider accept Medicare as full payment?”
No telehealth indicator
CMS shows this indicator only when recent Medicare claims include telehealth services. The clinician may still offer telehealth; ask the office.
Source: CMS, Telehealth Indicator on Medicare Care Compare (fact sheet, January 2023); CMS Doctors and Clinicians, CMS release of October 2, 2026.
Compared with the same specialty in Decorah and Iowa
3 active clinicians are listed under Nurse Practitioner with a practice address in Decorah, IA (1,304 in Iowa).
Addresses are self-reported to NPPES and may be out of date.
Sources: CMS Doctors and Clinicians, CMS release of October 2, 2026, CMS NPPES NPI Registry. Specialty names follow the NUCC Health Care Provider Taxonomy.
Text: T-MedInfo · Report an error.
Specialties & License Numbers Reported to NPPES
NUCC Taxonomy Code: 363L00000X
(1) A registered nurse provider with a graduate degree in nursing prepared for advanced practice involving independent and interdependent decision making and direct accountability for clinical judgment across the health care continuum or in a certified specialty. (2) A registered nurse who has completed additional training beyond basic nursing education and who provides primary health care services in accordance with state nurse practice laws or statutes. Tasks performed by nurse practitioners vary with practice requirements mandated by geographic, political, economic, and social factors. Nurse practitioner specialists include, but are not limited to, family nurse practitioners, gerontological nurse practitioners, pediatric nurse practitioners, obstetric-gynecologic nurse practitioners, and school nurse practitioners.
Additional State Medicaid & Healthcare Payer Identifiers
Clinicians Sharing This Practice Address or Phone
Clinicians sharing this NPPES address, phone or fax; a shared contact does not mean they work together.
Emergency Medicine
Doctor of Medicine (M.D.)
Family Medicine
Doctor of Osteopathic Medicine (D.O.)
Physician Assistant - Medical
Physician Assistant
Pathology - Clinical Pathology
Doctor of Medicine (M.D.)
Surgery
Doctor of Medicine (M.D.)
Family Medicine
Doctor of Medicine (M.D.)
Career & Practice History
NPI enumerated March 31, 2006.
No changes to the name, practice address, taxonomy or NPI status in this record have been observed in the monthly NPPES data files from January 2017 to November 2026.
NPI Administrative Meta
Other Nurse Practitioners in Decorah
Mailing Address
901 Montgomery St
Decorah, IA 521012325
Phone: 5633829671