Doctor profile · Federal record

Dr. Olwen Hahn, M.D.

Hematology & Oncology Physician (CMS: Hematology/Oncology) · Chicago, IL

  • NPI 1992823611
  • Accepts Medicare
  • MIPS 87.7 / 100 · 2023
  • 25 yrs in practice
  • Female
  • Solo practice
  • No sanctions

Practice & contact

NPPES Updated May 11, 2026
Primary practice
5841 S Maryland Ave, Mc 2115
Chicago, IL 606371447
(773) 702-5381
fax (773) 702-3163

Credentials & registration

NPPES · NUCC
NPI registered
March 2007 — 19 yrs on file
Profile last updated
July 8, 2007
Year of graduation
2001 — 25 yrs since
Specialty taxonomy
207RH0003X — NUCC code

Federal sanctions & exclusions

OIG LEIE Updated May 11, 2026

No sanctions, exclusions or revocations on file

Checked against OIG LEIE on NPI 1992823611. Last verified May 11, 2026.

Medicare procedures · 2023

Top services delivered

CMS Provider Utilization
Total services
253
Distinct HCPCS
3
Medicare allowed
$38,023
HCPCS Description Services Patients Avg allowed
99215 Established patient office or other outpatient visit, 40-54 minutes 143 74 $150
99233 Subsequent hospital care with moderate levelof medical decision making, if using time, at least 50 minutes 57 24 $125
99223 Initial hospital care with moderate level of medical decision making, if using time, at least 75 minutes 53 52 $179

In context: peer comparison

Among 77 peers in this city , average services per provider: 870. This provider delivers 0.3× the peer median.

Open Payments

Industry payments received

CMS Open Payments
All-time total
$1,737
Transactions
11
Manufacturers
1
Payer (manufacturer) Industry Txns Amount
AstraZeneca UK Limited 11 $1,736.99

By nature of payment

Travel and Lodging
$1,118
Food and Beverage
$619

Medicare Part D · 2023

Top prescriptions

CMS Part D Prescriber
Total claims
363
Patients
90
Total drug cost
$1,443,972
Drug Type Claims Patients Total cost
Anastrozole Generic 154 50 $4,845
Letrozole Generic 39 16 $2,193
Exemestane Generic 35 11 $5,778
Tamoxifen Citrate Generic 33 13 $1,111
Verzenio (Abemaciclib) Brand 28 0 $304,330
Kisqali (Ribociclib Succinate) Brand 22 0 $339,626
Ibrance (Palbociclib) Brand 16 0 $257,896
Piqray (Alpelisib) Brand 14 0 $282,231
Orserdu (Elacestrant Hcl) Brand 11 0 $238,663
Xarelto (Rivaroxaban) Brand 11 0 $7,299

Frequently asked questions

Auto-generated from federal data
What is Dr. Olwen Hahn's medical specialty?
Dr. Olwen Hahn practices Hematology & Oncology Physician in Chicago, IL.
Where does Dr. Olwen Hahn practice?
Dr. Olwen Hahn practices at 5841 S Maryland Ave, Chicago, IL 606371447. Office phone: 7737025381.
What is Dr. Olwen Hahn's NPI?
Dr. Olwen Hahn's National Provider Identifier (NPI) is 1992823611, issued by NPPES.
Does Dr. Olwen Hahn accept Medicare assignment?
Yes. Dr. Olwen Hahn accepts Medicare assignment, meaning Medicare-allowed amounts are accepted as full payment for covered services.
What procedures does Dr. Olwen Hahn commonly perform?
Top Medicare-reported procedures in 2023: Established patient office or other outpatient visit (HCPCS 99215); Subsequent hospital care with moderate levelof medical decision making (HCPCS 99233); Initial hospital care with moderate level of medical decision making (HCPCS 99223). Source: CMS Medicare Physician & Other Practitioners file.