Doctor profile · Federal record

Dr. Gregory Shirk, DC

Chiropractor (CMS: Chiropractic) · Mason City, IA

  • NPI 1629064464
  • Accepts Medicare
  • 31 yrs in practice
  • Male
  • Solo practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
630 1St St Nw
Mason City, IA 504012947
(641) 423-4455
fax (641) 423-0354

Credentials & registration

NPPES · NUCC
NPI registered
September 2005 — 21 yrs on file
Profile last updated
November 19, 2014
Year of graduation
1995 — 31 yrs since
Specialty taxonomy
111N00000X — NUCC code
State license (1)
Iowa #A05882
Medicaid
IA #0121657

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1629064464. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
1,859
Distinct HCPCS
2
Medicare allowed
$69,336
HCPCS Description Services Patients Avg allowed
98941 Chiropractic manipulative treatment, 3-4 spinal regions 1,769 168 $38
98940 Chiropractic manipulative treatment, 1-2 spinal regions 90 38 $26

In context: peer comparison

Among 5 peers in this city , average services per provider: 833. This provider delivers 2.2× the peer median.

Frequently asked questions

Auto-generated from federal data
What is Dr. Gregory Shirk's medical specialty?
Dr. Gregory Shirk practices Chiropractor in Mason City, IA.
Where does Dr. Gregory Shirk practice?
Dr. Gregory Shirk practices at 630 1St St Nw, Mason City, IA 504012947. Office phone: 6414234455.
What is Dr. Gregory Shirk's NPI?
Dr. Gregory Shirk's National Provider Identifier (NPI) is 1629064464, issued by NPPES.
Does Dr. Gregory Shirk accept Medicare assignment?
Yes. Dr. Gregory Shirk accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Gregory Shirk commonly perform?
Top Medicare-reported procedures in 2023: Chiropractic manipulative treatment, 3-4 spinal regions (HCPCS 98941); Chiropractic manipulative treatment, 1-2 spinal regions (HCPCS 98940). Source: CMS Medicare Physician & Other Practitioners file.