ROBERT ALLAN ALTER M.D.
NPI 1821064585
Internal Medicine - Geriatric Medicine in Chicago, IL

Q: What is Robert Alter's NPI number?

The NPI number for Robert Alter is 1821064585. It was assigned to this individual provider in the NPPES registry on February 23, 2006.

Q: What is Robert Alter's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Geriatric Medicine, with taxonomy code 207RG0300X.

Q: When was this NPI record last updated?

The NPPES record for Robert Alter was last updated on July 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 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.

Active since February 23, 2006PECOS Enrolled

2545 S KING DR, CHICAGO, IL 60616(312) 842-7117(312) 326-2102 Get Directions Write a Review

NPPES record last updated: July 13, 2026. Verified against the NPPES registry weekly; last sync: October 25, 2026.

Record update history: Jul 13, 2026, Sep 11, 2025 (2 updates tracked since 2025).

On this page

About Robert Allan Alter M.d. NPPES

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

ROBERT ALLAN ALTER M.D. (NPI 1821064585) is an individual geriatric medicine provider in Chicago, Illinois and active in the NPI registry since February 2006. He is enrolled in Medicare PECOS.

NPPES Registry Identity

NPI1821064585

Entity TypeIndividualMale

Primary Taxonomy207RG0300X

Provider Legal NameROBERT ALLAN ALTERCredential: M.D.

Location Address2545 S KING DRChicago, IL 60616-2441

Mailing Address2311 W 22nd St, Suite 202Oak Brook, IL 60523-1225 · (630) 320-1160 · Fax (630) 320-1231

Phone(312) 842-7117

Fax(312) 326-2102

Sole ProprietorNo

Enumeration DateFebruary 23, 2006

Last NPPES UpdateJuly 13, 20262 updates tracked since enumeration

✔ NPI 1821064585 is a valid, active identifier and passes the ISO check-digit test.

Specialties & Licenses 2

★ Primary SpecialtyInternal Medicine · Geriatric MedicineAllopathic & Osteopathic Physicians

Taxonomy Code207RG0300X

Definition

An internist who has special knowledge of the aging process and special skills in the diagnostic, therapeutic, preventive and rehabilitative aspects of illness in the elderly. This specialist cares for geriatric patients in the patient's home, the office, long-term care settings such as nursing homes and the hospital.

Also ListedInternal MedicineTaxonomy 207R00000X

2545 S KING DR, Chicago, IL 60616

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Medicare Participation & PECOS CMS

Medicare enrollment, assignment, billing reassignment, and ordering and referring status from CMS.

Medicare Enrollment Status

✔

Enrolled in Medicare (PECOS)

Robert Allan Alter M.d. 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 Robert Alter reassigns Medicare billing to 1 organization. The organization bills Medicare for the services this provider delivers there.

Advocate Health And Hospitals Corporation

7.1 mi

General Acute Care Hospital

3435 W VAN BUREN ST
Chicago, IL 60624

Reassigned Medicare billing, Illinois enrollment
4,870 clinicians in this Medicare group

NPI 1801838339 (773) 265-7700

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 60616 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.

DR. ADESHOLA EZEOKOLI MD

Internal Medicine

2545 S KING DR
CHICAGO, IL 60616

Cook County (312) 842-7117

JOHN SOBOLSKI M.D.

Internal Medicine (Cardiovascular Disease)

2545 S KING DR
CHICAGO, IL 60616

Cook County (312) 842-7117

LAWRENCE NGU M.D.

Internal Medicine

2545 S KING DR
CHICAGO, IL 60616

Cook County (312) 842-7117

DAVID STERN M.D.

Surgery

2545 S KING DR
CHICAGO, IL 60616

Cook County (312) 842-7117

MRS. KATHLEEN LACCI BIENIA PA-C, MMSC

Physician Assistant

2545 S KING DR, SYKES ADVOCATE MEDICAL GROUP
CHICAGO, IL 60616

Cook County (312) 842-7117

SANJAY VASUDEO JOAG M.D.

Hospitalist

2545 S KING DR
CHICAGO, IL 60616

Cook County (312) 842-7117

COLLETTE ARA HONORE M.D.

Dermatology

2545 S KING DR
CHICAGO, IL 60616

Cook County (312) 842-7117

VIMALA SANTHANAM M.D.

Internal Medicine (Cardiovascular Disease)

2545 S KING DR
CHICAGO, IL 60616

Cook County (312) 842-7117

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 Robert Alter's NPI number?

The NPI number for Robert Alter is 1821064585. It was assigned to this individual provider in the NPPES registry on February 23, 2006.

Where is Robert Alter located?

Robert Alter practices at 2545 S King Dr, Chicago, IL 60616. The listed phone number is (312) 842-7117.

What is Robert Alter's specialty?

The primary specialty registered for this NPI is Internal Medicine, specializing in Geriatric Medicine, with taxonomy code 207RG0300X.

Is Robert Alter enrolled in Medicare?

Yes. Robert Alter is registered in the Medicare PECOS enrollment system.

Which organization bills Medicare for Robert Alter's services?

According to the CMS Revalidation Reassignment List (October 2026 release), Robert Alter reassigns Medicare benefits to Advocate Health And Hospitals Corporation (Chicago, IL). 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 Robert Alter's services. Reassignment records can lag staffing changes; confirm current arrangements with the organization.

When was this NPI record last updated?

The NPPES record for Robert Alter was last updated on July 13, 2026. NPI Profile syncs weekly with the NPPES registry data releases published by CMS. This NPI record was last updated 3 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.