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DR. JOHN E MAYER PH.D.
NPI 1790816841
Psychologist - Clinical in Chicago, IL

Active since March 08, 2007PECOS EnrolledAccepts Medicare Assignment
55 E WASHINGTON ST, 38TH FLOOR, CHICAGO, IL 60602(312) 917-1240(312) 917-1010 Get Directions Write a Review

NPPES record last updated: July 8, 2007. Verified against the NPPES registry weekly; last sync: October 25, 2026.

About Dr. John E Mayer Ph.d. NPPES

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

DR. JOHN E MAYER PH.D. (NPI 1790816841) is an individual clinical provider in Chicago, Illinois, licensed in Illinois (071-02554) and active in the NPI registry since March 2007. He is enrolled in Medicare PECOS and is a graduate of Other (1979).

NPPES Registry Identity

NPI1790816841
Entity TypeIndividualMale
Primary Taxonomy103TC0700X
Provider Legal NameDR. JOHN E MAYERCredential: PH.D.
Location Address55 E WASHINGTON ST, 38TH FLOORChicago, IL 60602-2103
Mailing Address55 E Washington St, 38th FloorChicago, IL 60602-2103 · (312) 917-1240 · Fax (312) 917-1010
Phone(312) 917-1240
Fax(312) 917-1010
Sole ProprietorYes
Medical School CMSOtherGraduated 1979
Enumeration DateMarch 8, 2007
Last NPPES UpdateJuly 8, 2007
✔ NPI 1790816841 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses

★ Primary SpecialtyPsychologist · ClinicalBehavioral Health & Social Service Providers
Taxonomy Code103TC0700X
License✔ Licensed in IL · 071-02554
Definition
A psychologist who provides continuing and comprehensive mental and behavioral health care for individuals and families; consultation to agencies and communities; training, education and supervision; and research-based practice. It is a specialty in breadth -- one that is broadly inclusive of severe psychopathology -- and marked by comprehensiveness and integration of knowledge and skill from a broad array of disciplines within and outside of psychology proper. The scope of clinical psychology encompasses all ages, multiple diversities and varied systems.
55 E WASHINGTON ST, Chicago, IL 60602
Open in Google Maps ↗

Other Identifiers 1

Medicare UPINY49528IL

Accepted Insurance

The full list of accepted plans is on the Insurance tab. Issuers include Oscar Health, Oscar Insurance Company, UnitedHealthcare.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. John E Mayer Ph.d. 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 ID648284307
PECOS Enrollment IDI20060201000721
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 John Mayer reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Doctor On Demand Professionals P C
1,860 mi
Family Medicine
1 CALIFORNIA ST STE 2300
San Francisco, CA 94111
  • Reassigned Medicare billing, Illinois enrollment
  • 22 clinicians in this Medicare group
NPI 1174931448 (800) 997-6196

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 60602 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
$183.39 typical visit price
range $60.08 – $183.39
Typical copayment $45.84 (range $15.02 – $45.84)
Most-billed visit code 99205
Established Patient
$105.70 typical visit price
range $18.97 – $148.12
Typical copayment $26.42 (range $4.74 – $37.03)
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.

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.

SHARON PIETRZAK MA, LCPC, CCDVC
Counselor (Professional)
55 E WASHINGTON ST, SUITE 621
CHICAGO, IL 60602
Cook County (708) 293-0070
DR. GARY G WEGMANN DDS
Dentist
55 E WASHINGTON ST, SUITE 3601
CHICAGO, IL 60602
Cook County (312) 551-0500
JUSTIN EVAN TOBIN LCSW
Social Worker (Clinical)
55 E WASHINGTON ST, SUITE 2700
CHICAGO, IL 60602
Cook County (773) 308-3468
MR. DAVID LEE CIESLA MA, LCPC
Counselor (Professional)
55 E WASHINGTON ST, SUITE 2801
CHICAGO, IL 60602
Cook County (312) 208-9499
DR. JAY CALLAHAN PHD, LCSW
Social Worker (Clinical)
55 E WASHINGTON ST, SUITE 2801
CHICAGO, IL 60602
Cook County (312) 372-4823
MR. LAWRENCE MICHAEL RUFFOLO L.C.S.W.
Social Worker (Clinical)
55 E WASHINGTON ST, SUITE 2900
CHICAGO, IL 60602
Cook County (847) 338-2564
MADELINE MUECKE LCSW, BCD
Social Worker (Clinical)
55 E WASHINGTON ST, SUITE 3100
CHICAGO, IL 60602
Cook County (773) 929-7696
DR. CHRISTOPHER FORD CHOYKE DDS
Dentist (General Practice)
55 E WASHINGTON ST
CHICAGO, IL 60602
Cook County (312) 782-5291

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 John Mayer's NPI number?

The NPI number for John Mayer is 1790816841. It was assigned to this individual provider in the NPPES registry on March 8, 2007.

Where is John Mayer located?

John Mayer practices at 55 E Washington St 38th Floor, Chicago, IL 60602. The listed phone number is (312) 917-1240.

What is John Mayer's specialty?

The primary specialty registered for this NPI is Psychologist, specializing in Clinical, with taxonomy code 103TC0700X.

Is John Mayer enrolled in Medicare?

Yes. John Mayer 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 John Mayer's services?

According to the CMS Revalidation Reassignment List (October 2026 release), John Mayer reassigns Medicare benefits to Doctor On Demand Professionals P C (San Francisco, CA). 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 John Mayer's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

What insurance does John Mayer accept?

Health plans from Oscar Health, Oscar Insurance Company and UnitedHealthcare list John Mayer 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 John Mayer was last updated on July 8, 2007. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 19 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.