Ilysa Diamond, DO
NPI 1356596332 · Gastroenterology Physician · Oak Park, IL
Enrolled with Medicare as Practitioner - Gastroenterology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Ilysa Diamond, DO is a Gastroenterology Physician provider in Oak Park, IL (NPI 1356596332).
Provider details
- NPI number
- 1356596332
- Entity type
- Individual
- Primary specialty
- Gastroenterology PhysicianAllopathic & Osteopathic Physicians
- Credential
- DO
- Sex
- Female
- Sole proprietor
- Yes
- License
- 036120184 (IL)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure25% of score
17 yrs in NPPES registry
- Profile completeness25% of score
100% of core fields populated
- Practice footprint15% of score
4 documented practice locations
- Medicare service volume (vs. specialty peers)25% of score
192 Medicare services, 2024 (ranked within specialty)
- Open Payments transparency10% of score
Has Open Payments disclosures (2024)
Medicare volume is ranked against active providers in the same specialty. Signals a provider has no public data for (e.g. Medicare claims) are left out of the score entirely — never counted as zero — so providers without that data are not penalized. See the full formula and weights in our .
What this provider does (Medicare)
Based on Medicare fee-for-service claims, 2024; not all care is captured.
| Service (HCPCS) | Medicare services | Typical Medicare-allowed (2024) |
|---|---|---|
| Established Patient Office Or Other Outpatient Visit With Low Level OD Decision Making, If Using Time, 20 Minutes Or More99213 | 45 | $94 |
| Established Patient Office Or Other Outpatient Visit With Moderate Level of Decision Making, If Using Time, 30 Minutes Or More99214 | 45 | $132 |
| New Patient Office Or Other Outpatient Visit With Moderate Level of Medical Decision Making, If Using Time, 45 Minutes Or More99204 | 27 | $169 |
| Biopsy of Large Bowel Using a Flexible Endoscope45380 | 26 | $141 |
| Biopsy of Esophagus, Stomach, And/Or Upper Small Bowel Using a Flexible Endoscope43239 | 24 | $79 |
| New Patient Office Or Other Outpatient Visit With Low Level of Medical Decision Making, If Using Time, 30 Minutes Or More |
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 5 distinct drugs on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Pantoprazole Sodium | 89 | 51 |
| Famotidine | 23 | 16 |
| Lubiprostone | 23 | — |
| Linaclotidebrand: Linzess | 16 | — |
| Sodium, Potassium,mag Sulfatesbrand: Sod Sulf-Potass Sulf-Mag Sulf | 13 | 12 |
Medicare Part D only. These counts cover prescriptions paid through Medicare Part D in 2024 — they do notinclude cash-pay, commercial-insurance, Medicaid, or Part B–administered drugs, and badly undercount high cash-pay categories (e.g. GLP-1 weight-loss, testosterone, and ED medications). Any drug with 10 or fewer claims is omitted by CMS, and beneficiary counts under 11 are suppressed — so a missing drug means no Part D record, never zero. This is a factual claims summary, not an endorsement, not medical advice, and not a consumer report. Source: CMS Medicare Part D Prescribers — by Provider and Drug.
Transparency — industry payments
Based on CMS Open Payments, 2024; not all care is captured.
$850 across 35 records (Open Payments 2024)
Open Payments discloses payments and transfers of value (meals, travel, consulting, research, royalties) from drug and device makers to providers. This is a transparency signal, not a verdict — such payments are legal and common, and their presence is neither an endorsement nor a criticism. Source: CMS Open Payments, program year 2024.
Practice location
Mailing address
Additional practice locations (3)
- 3101 N Harlem Ave # 3115Chicago, IL 60634-4543Phone: (773) 889-2000
- 3 Erie CtOak Park, IL 60302-2519Phone: (708) 613-4417
- 11104 Parkview Circle Dr Ste 310Fort Wayne, IN 46845-1733Phone: (260) 266-5230Fax: (260) 458-5972
Registry dates
- Enumerated
- 2008-11-18
- Last updated
- 2024-09-03
- Certified
- 2024-09-03
Frequently asked questions
- What is Ilysa Diamond's NPI number?
- Ilysa Diamond's National Provider Identifier (NPI) is 1356596332, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Ilysa Diamond's specialty?
- Ilysa Diamond is listed in the NPPES registry with a primary specialty of Gastroenterology Physician (Allopathic & Osteopathic Physicians).
- Where is Ilysa Diamond located?
- Ilysa Diamond's practice location on file with NPPES is 1010 Lake St Ste 424, Oak Park, IL 60301-1185.
- What is Ilysa Diamond's phone number?
- The practice phone number listed in the NPPES registry for Ilysa Diamond is (708) 613-4417.
- Does Ilysa Diamond accept Medicare?
- Ilysa Diamond is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Ilysa Diamond's NPI active?
- Yes — Ilysa Diamond's NPI (1356596332) is active in the NPPES registry as of the last update on 2024-09-03.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.