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DR. GREGORY CHARLES HAHN DO
NPI 1972702215
Psychiatry & Neurology - Psychiatry in Merriam, KS

Active since July 17, 2007PECOS EnrolledAccepts Medicare Assignment
9100 W 74TH ST, MERRIAM, KS 66204(913) 663-2642(913) 632-2696 Get Directions Write a Review

NPPES record last updated: September 5, 2025. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Sep 5, 2025, May 12, 2025, Jul 25, 2024 and 6 more (9 updates tracked since 2017).

About Dr. Gregory Charles Hahn Do NPPES

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

DR. GREGORY CHARLES HAHN DO (NPI 1972702215) is an individual psychiatry provider in Merriam, Kansas, licensed in Kansas (05-39922) and active in the NPI registry since July 2007. He is enrolled in Medicare PECOS, is affiliated with Stormont Vail Hospital, and is a graduate of Other (2007).

NPPES Registry Identity

NPI1972702215
Entity TypeIndividualMale
Primary Taxonomy2084P0800X
Provider Legal NameDR. GREGORY CHARLES HAHNCredential: DO
Location Address9100 W 74TH STMerriam, KS 66204-4004
Mailing Address9100 W 74th StMerriam, KS 66204-4004 · (913) 663-2642 · Fax (913) 632-2696
Phone(913) 663-2642
Fax(913) 632-2696
Sole ProprietorNo
Medical School CMSOtherGraduated 2007
Enumeration DateJuly 17, 2007
Last NPPES UpdateSeptember 5, 20259 updates tracked since enumeration
NPPES CertifiedSeptember 5, 2025
✔ NPI 1972702215 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyPsychiatry & Neurology · PsychiatryAllopathic & Osteopathic Physicians
Taxonomy Code2084P0800X
License✔ Licensed in KS · 05-39922
Definition
A Psychiatrist specializes in the prevention, diagnosis, and treatment of mental disorders, emotional disorders, psychotic disorders, mood disorders, anxiety disorders, substance-related disorders, sexual and gender identity disorders and adjustment disorders. Biologic, psychological, and social components of illnesses are explored and understood in treatment of the whole person. Tools used may include diagnostic laboratory tests, prescribed medications, evaluation and treatment of psychological and interpersonal problems with individuals and families, and intervention for coping with stress, crises, and other problems.
9100 W 74TH ST, Merriam, KS 66204
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Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Ambetter from Sunflower Health Plan, Ambetter Health, Ambetter Health of Delaware 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 Charles Hahn Do 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 ID648541920
PECOS Enrollment IDI20170804000381
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 Reassignments

2

Medicare enrollment records show Gregory Hahn reassigns Medicare billing to 2 organizations. Each organization bills Medicare for the services this provider delivers there; the nearest is listed first.

Shawnee Mission Medical Center Inc
Same address
Family Medicine
9100 W 74TH ST
Merriam, KS 66204
  • Reassigned Medicare billing, Kansas enrollment
  • 384 clinicians in this Medicare group
NPI 1992735690 (913) 676-2000
Cotton-O'neil Clinic Revocable Trust
54 mi
Internal Medicine
901 SW GARFIELD AVE
Topeka, KS 66606
  • Reassigned Medicare billing, Kansas enrollment
  • 854 clinicians in this Medicare group
NPI 1811944457 (785) 354-9591

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 8

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.

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.
264 services113 patients
Hospital discharge day management, more than 30 minutes 99239
Hospital discharge day management over 30 minutes involves a detailed process to ensure a smooth transition from hospital to home. It includes final examinations, discussion of your hospital stay, post-discharge instructions, and coordinating follow-up care.
70 services58 patients
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 99233
Follow-up hospital inpatient care per day typically involves a 35-minute check-up by your healthcare provider. This service includes monitoring your health progress, adjusting your treatment plan if needed, and answering any questions you may have about your condition or care.
66 services34 patients
Established patient office or other outpatient visit with high level of medical decision making, if using time, 40 minutes or more 99215
This service involves a follow-up appointment for existing patients, lasting between 40 to 54 minutes. During this time, your healthcare provider will assess your current health status, discuss any changes or concerns, review your treatment plan, and answer any questions you may have.
61 services43 patients
Psychiatric diagnostic evaluation with medical services 90792
A psychiatric diagnostic evaluation with medical services is a comprehensive assessment. It includes a detailed examination of your mental health and physical wellbeing, as well as your personal and family history. This evaluation aids in creating an effective treatment plan.
50 services49 patients
Subsequent hospital care with moderate levelof medical decision making, if using time, at least 35 minutes 99232
Follow-up hospital inpatient care involves daily check-ups while you're admitted in the hospital. Typically, a healthcare provider spends about 25 minutes each day reviewing your condition, adjusting treatment if needed, and answering any questions you might have.
40 services22 patients

Hospital Affiliations CMS Care Compare 2

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

Stormont Vail Hospital

Acute Care Hospitals · Topeka, KS
3/5 CMS rating
OwnershipVoluntary non-profit - Private
CMS Certification Number170086
Location1500 SW 10th AvenueTopeka, KS 66604 · Shawnee County
Emergency services Birthing friendly

Adventhealth Shawnee Mission

Acute Care Hospitals · Shawnee Mission, KS
4/5 CMS rating
OwnershipVoluntary non-profit - Church
CMS Certification Number170104
Location9100 W 74th StreetShawnee Mission, KS 66204 · Johnson County
Emergency services Birthing friendly

Physician Visit Costs CMS claims · ZIP area

Typical Medicare office-visit costs in the 66204 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
$161.67 typical visit price
range $53.00 – $161.67
Typical copayment $40.41 (range $13.25 – $40.41)
Most-billed visit code 99205
Established Patient
$66.40 typical visit price
range $16.88 – $132.11
Typical copayment $16.60 (range $4.22 – $33.02)
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 20

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

MRS. MARY SWINGLE CRNA
Nurse Anesthetist, Certified Registered
9100 W 74TH ST
MERRIAM, KS 66204
Johnson County (913) 632-2230
RHEUMATOLOGY SPECIALISTS OF KANSAS CITY PA
Specialist
9100 W 74TH ST
OVERLAND PARK, KS 66204
Johnson County (816) 753-5736
MS. PENNY ANN WALTER RD, LD
Dietitian, Registered
9100 W 74TH ST
SHAWNEE MISSION, KS 66204
Johnson County (913) 676-2195
LORENE CREASSER ARNP
Nurse Practitioner (Family)
9100 W 74TH ST
SHAWNEE MISSION, KS 66204
Johnson County (913) 676-2200
MS. ANN WHEELER BCBA
Behavior Analyst
9100 W 74TH ST
SHAWNEE MISSION, KS 66204
Johnson County (913) 676-2253
TYLER DAVIS DO
Anesthesiology
9100 W 74TH ST
SHAWNEE MISSION, KS 66204
Johnson County (913) 676-2000
ELIZABETH DANIELLE FLESHMAN
Registered Nurse
9100 W 74TH ST
MERRIAM, KS 66204
Johnson County (913) 909-2776
MITCHELL YOUNG
Nurse Anesthetist, Certified Registered
9100 W 74TH ST
MERRIAM, KS 66204
Johnson County (913) 676-2000

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 Hahn's NPI number?

The NPI number for Gregory Hahn is 1972702215. It was assigned to this individual provider in the NPPES registry on July 17, 2007.

Where is Gregory Hahn located?

Gregory Hahn practices at 9100 W 74th St, Merriam, KS 66204. The listed phone number is (913) 663-2642.

What is Gregory Hahn's specialty?

The primary specialty registered for this NPI is Psychiatry & Neurology, specializing in Psychiatry, with taxonomy code 2084P0800X.

Is Gregory Hahn enrolled in Medicare?

Yes. Gregory Hahn 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 organizations bill Medicare for Gregory Hahn's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Gregory Hahn reassigns Medicare benefits to 2 organizations: Shawnee Mission Medical Center Inc (Merriam, KS) and Cotton-O'neil Clinic Revocable Trust (Topeka, KS). Each 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 Hahn's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does Gregory Hahn accept?

Health plans from Ambetter Health, Ambetter Health of Delaware, Ambetter from Sunflower Health Plan, Ambetter of Oklahoma and Blue Cross and Blue Shield of Kansas City list Gregory Hahn 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 Gregory Hahn affiliated with any hospitals?

According to CMS data, Gregory Hahn is affiliated with Stormont Vail Hospital and Adventhealth Shawnee Mission.

When was this NPI record last updated?

The NPPES record for Gregory Hahn was last updated on September 5, 2025. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 13 months 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.