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DR. GREGORY J SHIRK DC
NPI 1629064464
Chiropractor in Mason City, IA

Active since September 27, 2005Accepts Medicare Assignment
630 1ST ST NW, MASON CITY, IA 50401(641) 423-4455(641) 423-0354 Get Directions Write a Review

NPPES record last updated: November 19, 2014. Verified against the NPPES registry weekly; last sync: November 01, 2026.

About Dr. Gregory J Shirk Dc NPPES

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

DR. GREGORY J SHIRK DC (NPI 1629064464) is an individual chiropractor in Mason City, Iowa, licensed in Iowa (A05882) and active in the NPI registry since September 2005. He is a graduate of Palmer College Chiropractic - Davenport (1995).

NPPES Registry Identity

NPI1629064464
Entity TypeIndividualMale
Primary Taxonomy111N00000X
Provider Legal NameDR. GREGORY J SHIRKCredential: DC
Location Address630 1ST ST NWMason City, IA 50401-2947
Mailing Address630 1st St NwMason City, IA 50401-2947 · (641) 423-4455 · Fax (641) 423-0354
Phone(641) 423-4455
Fax(641) 423-0354
Sole ProprietorYes
Medical School CMSPalmer College Chiropractic - DavenportGraduated 1995
Enumeration DateSeptember 27, 2005
Last NPPES UpdateNovember 19, 2014
✔ NPI 1629064464 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyChiropractorChiropractic Providers
Taxonomy Code111N00000X
License✔ Licensed in IA · A05882
Definition
A provider qualified by a Doctor of Chiropractic (D.C.), licensed by the State and who practices chiropractic medicine -that discipline within the healing arts which deals with the nervous system and its relationship to the spinal column and its interrelationship with other body systems.
630 1ST ST NW, Mason City, IA 50401
Open in Google Maps ↗

Other Identifiers 3

Medicare PIN59606IA
Other59606IA · Bcbs
Medicaid0121657IA

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 and accepts Medicare assignment

Dr. Gregory J Shirk Dc 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 ID244130532
PECOS Enrollment IDI20040112000364

Medicare Billing Reassignment

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

Shirk PC
Same address
Chiropractor
630 1ST ST NW
Mason City, IA 50401
  • Reassigned Medicare billing, Iowa enrollment
NPI 1558673442 (641) 423-4455

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 2

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.

Chiropractic manipulative treatment, 3-4 spinal regions 98941
Chiropractic manipulative treatment for 3-4 spinal regions involves a trained professional applying controlled force to specific areas of your spine. This can help alleviate pain, improve physical function, and support your body's natural healing process.
1,649 services147 patients
Chiropractic manipulative treatment, 1-2 spinal regions 98940
Chiropractic manipulative treatment focuses on adjusting your spine to improve your body's physical function. In this service, a chiropractor applies controlled force to 1-2 spinal regions. This helps to restore mobility and alleviate discomfort in those areas.
34 services18 patients

Other Providers at the Same Location NPPES

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

SHIRK PC
Chiropractor
630 1ST ST NW
MASON CITY, IA 50401
Cerro Gordo County (641) 423-4455

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 Gregory Shirk's NPI number?

The NPI number for Gregory Shirk is 1629064464. It was assigned to this individual provider in the NPPES registry on September 27, 2005.

Where is Gregory Shirk located?

Gregory Shirk practices at 630 1st St NW, Mason City, IA 50401. The listed phone number is (641) 423-4455.

What is Gregory Shirk's specialty?

The primary specialty registered for this NPI is Chiropractor with taxonomy code 111N00000X.

Is Gregory Shirk enrolled in Medicare?

Yes. Gregory Shirk 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 Gregory Shirk's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Gregory Shirk reassigns Medicare benefits to Shirk PC (Mason City, 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 Gregory Shirk's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Gregory Shirk accept?

Health plans from Ambetter Health, Ambetter Health of Delaware, Ambetter from NH Healthy Families, Ambetter from Sunflower Health Plan and Oscar Health and 2 other insurers list Gregory Shirk 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 Gregory Shirk was last updated on November 19, 2014. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 11 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.