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DELWYN LEE LASSEN MD
NPI 1558346015
Family Medicine in Sioux Center, IA

Active since December 07, 2005PECOS Enrolled
94/100
CMS Quality Rating
33 4TH ST NW, SIOUX CENTER, IA 51250(712) 722-1700(712) 722-1770 Get Directions Write a Review

NPPES record last updated: December 15, 2020. Verified against the NPPES registry weekly; last sync: October 18, 2026.

Record update history: Dec 15, 2020, Mar 17, 2018 (2 updates tracked since 2018).

About Delwyn Lee Lassen Md NPPES

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

DELWYN LEE LASSEN MD (NPI 1558346015) is an individual family medicine provider in Sioux Center, Iowa, licensed in Iowa (21150) and active in the NPI registry since December 2005. He is enrolled in Medicare PECOS and maintains a secondary practice location in Sioux City.

NPPES Registry Identity

NPI1558346015
Entity TypeIndividualMale
Primary Taxonomy207Q00000X
Provider Legal NameDELWYN LEE LASSENCredential: MD
Location Address33 4TH ST NWSioux Center, IA 51250-1870
Mailing Address33 4th St NwSioux Center, IA 51250-1870 · (712) 722-1700 · Fax (712) 722-1770
Phone(712) 722-1700
Fax(712) 722-1770
Sole ProprietorNo
Enumeration DateDecember 7, 2005
Last NPPES UpdateDecember 15, 20202 updates tracked since enumeration
NPPES CertifiedDecember 15, 2020
✔ NPI 1558346015 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyFamily MedicineAllopathic & Osteopathic Physicians
Taxonomy Code207Q00000X
License✔ Licensed in IA · 21150
Definition
Family Medicine is the medical specialty which is concerned with the total health care of the individual and the family. It is the specialty in breadth which integrates the biological, clinical, and behavioral sciences. The scope of family medicine is not limited by age, sex, organ system, or disease entity.
33 4TH ST NW, Sioux Center, IA 51250
Open in Google Maps ↗

Secondary Practice Location 1

Location 12501 Pierce StSioux City, IA 51104-3725 · Phone (712) 294-5000 · Fax (712) 294-5091

Other Identifiers 2

Medicaid1066548IA
Other1336127828Group Npi

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Ambetter from NH Healthy Families, Ambetter from Sunflower Health Plan, Ambetter Health 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 (PECOS)

Delwyn Lee Lassen Md is registered in the CMS Provider Enrollment, Chain and Ownership System (PECOS).

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 Delwyn Lassen reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Greater Sioux Community Health Center Inc.
Same address
Federally Qualified Health Center (FQHC)
33 4TH ST NW
Sioux Center, IA 51250
  • Reassigned Medicare billing, Iowa enrollment
  • 18 clinicians in this Medicare group
NPI 1053582098 (712) 722-1700

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

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 51250 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
$81.84 typical visit price
range $52.96 – $161.40
Typical copayment $20.46 (range $13.24 – $40.35)
Most-billed visit code 99203
Established Patient
$94.05 typical visit price
range $16.91 – $131.98
Typical copayment $23.51 (range $4.22 – $32.99)
Most-billed visit code 99214
Amounts reflect what Medicare beneficiaries in this ZIP area are typically charged for office visits. Patients with other coverage should check their individual plans.

Medicare Quality Performance CMS QPP · MIPS

Performance in the CMS Quality Payment Program: the MIPS final score across four weighted categories, and the individual quality measures reported to Medicare.

94/100
MIPS Final ScoreMerit-based Incentive Payment System · CMS Quality Payment Program
Scored through an Alternative Payment Model
Quality84.79
Promoting Interoperability98.22
Improvement Activities40

Other Providers at the Same Location NPPES 20

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

EMILY LEINEN ARNP PMHNP-BC FNP-BC
Nurse Practitioner (Psychiatric/Mental Health)
33 4TH ST NW
SIOUX CENTER, IA 51250
Sioux County (712) 722-1700
OSIRIS ARLET ORDAZ MA
Counselor (Mental Health)
33 4TH ST NW
SIOUX CENTER, IA 51250
Sioux County (712) 722-1700
GREATER SIOUX COMMUNITY HEALTH CENTER INC.
Clinic/Center (Federally Qualified Health Center (FQHC))
33 4TH ST NW
SIOUX CENTER, IA 51250
Sioux County (712) 722-1700
AMANDA RICKARD
Registered Nurse
33 4TH ST NW
SIOUX CENTER, IA 51250
Sioux County (712) 722-1700
DR. KENNETH F TJEERDSMA DDS
Dentist
33 4TH ST NW
SIOUX CENTER, IA 51250
Sioux County (712) 722-1700
JOLENE MARIE THYR LMSW
Social Worker
33 4TH ST NW
SIOUX CENTER, IA 51250
Sioux County (712) 722-1700
KENDRA MARIE BORCHERS PHARMD
Pharmacist
33 4TH ST NW
SIOUX CENTER, IA 51250
Sioux County (712) 722-1700
STACY LYNNE SCHAAP ARNP
Family Medicine
33 4TH ST NW
SIOUX CENTER, IA 51250
Sioux County (712) 722-1700

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 Delwyn Lassen's NPI number?

The NPI number for Delwyn Lassen is 1558346015. It was assigned to this individual provider in the NPPES registry on December 7, 2005.

Where is Delwyn Lassen located?

Delwyn Lassen practices at 33 4th St NW, Sioux Center, IA 51250. The listed phone number is (712) 722-1700.

What is Delwyn Lassen's specialty?

The primary specialty registered for this NPI is Family Medicine with taxonomy code 207Q00000X.

Is Delwyn Lassen enrolled in Medicare?

Yes. Delwyn Lassen is registered in the Medicare PECOS enrollment system.

Which organization bills Medicare for Delwyn Lassen's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Delwyn Lassen reassigns Medicare benefits to Greater Sioux Community Health Center Inc. (Sioux Center, IA). 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 Delwyn Lassen's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Delwyn Lassen accept?

Health plans from Ambetter Health, Ambetter Health of Delaware, Ambetter from NH Healthy Families, Ambetter from Sunflower Health Plan and Oscar Insurance Company and 2 other insurers list Delwyn Lassen 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.

When was this NPI record last updated?

The NPPES record for Delwyn Lassen was last updated on December 15, 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.