Individual provider

Lydia Breen, MD

Psychiatry Physician

Lydia Breen, MD is a Psychiatry Physician in Chicago, IL, registered under NPI 1518926203.

Getting there

The practice address on file is 211 E ONTARIO ST SUITE #1195, Chicago, IL 60611. We have not yet mapped what surrounds this office — parking, transit, and nearby pharmacies are added as our data collection reaches each location.

211 E ONTARIO ST SUITE #1195, Chicago, IL 60611 Open in Google Maps →

Credentials and Medicare

State licence
LicenceStateSpecialty
036107034 IL Psychiatry Physician primary

This provider holds licence 036107034 issued in IL. A licence number in NPPES reflects what was filed at registration — it does not confirm the licence is still active today.

Medicare (PECOS)

This NPI does not appear in the PECOS Medicare enrolment file. Providers who do not bill Medicare — or who bill only through a group's enrolment — will not appear here. It is not a sign of any problem with the registration.

What Psychiatry covers

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. NUCC Health Care Provider Taxonomy, code 2084P0800X
Allopathic & Osteopathic Physicians Psychiatry & Neurology Psychiatry

The taxonomy records how the provider classifies their own practice. It does not confirm which conditions they currently treat, whether they are accepting new patients, or which insurance they take — call the office for that.

Full NPPES record

An NPI-1 identifies a single person. It stays with the clinician for life, even if they move practice or change state, which is why the address on file can lag behind where they actually work today.

NPI1518926203 valid check digit
Entity typeIndividual (NPI-1)
Enumeration dateMar 21, 2006
Last updatedJul 13, 2026
StatusActive
Sole proprietorNo
GenderFemale
CredentialMD
Practice address 211 E ONTARIO ST
SUITE #1195
Chicago, IL 60611
(773) 381-3421
Fax (312) 988-9363
Mailing address 1037 W NORTHSHORE AVE #3N
Chicago, IL 60626
Other identifiers 036107034 · Medicaid (IL)
1633712 · Other (IL)
This record was updated on Jul 13, 2026, which is recent enough that the contact details are likely still accurate.

Number check

1518926203 passes the NPI check digit test The final digit 3 matches the value computed from the first nine digits, so this is a well-formed NPI.
How the check works, step by step

Every NPI carries a Luhn check digit — the same scheme used on credit cards. CMS prefixes the number with 80840 before computing it, which marks it as a US health identifier.

Digit 8 0 8 4 0 1 5 1 8 9 2 6 2 0
Doubled? ×2 ×2 ×2 ×2 ×2 ×2 ×2
Value 8 0 8 8 0 2 5 2 8 9 2 3 2 0

Sum = 57 · next multiple of 10 = 60 · check digit = 3 · actual last digit = 3

A valid check digit only means the number is well-formed. It does not mean the provider is licensed, active, or in good standing — those are separate questions answered by the sections above.

Common questions

What is NPI number 1518926203?
NPI 1518926203 is the National Provider Identifier assigned to Lydia Breen, MD in Chicago, IL. It is a 10-digit number issued by the Centers for Medicare & Medicaid Services and used on claims, referrals, and prescriptions to identify the provider.
What does Psychiatry cover?
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…
How do I contact Lydia Breen, MD?
The phone number on file with NPPES is (773) 381-3421, last updated Jul 13, 2026. Because NPPES is only updated when a provider files a change, call ahead to confirm the number and the current practice address before visiting.
Is NPI 1518926203 a valid number?
Yes. 1518926203 passes the Luhn check digit validation that CMS uses for NPI numbers, and it resolves to an active record in the registry.
How to use this page. Everything here comes from public federal records. Tips Health does not verify quality of care, confirm that a licence is currently active, or check malpractice history, and accepts no fees for placement. A listing is not a recommendation. Verify independently before seeking care.