Annika Nilsen, MD
NPI 1871048058 · Obstetrics & Gynecology Physician · Chicago, IL
Enrolled with Medicare as Practitioner - Obstetrics/Gynecology · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Annika Nilsen, MD is a Obstetrics & Gynecology Physician provider in Chicago, IL (NPI 1871048058).
Provider details
- NPI number
- 1871048058
- Entity type
- Individual
- Primary specialty
- Obstetrics & Gynecology PhysicianAllopathic & Osteopathic Physicians
- Credential
- MD
- Sex
- Female
- Sole proprietor
- Yes
- License
- 036170533 (IL)
Specialties & taxonomies
Allopathic & Osteopathic Physicians
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure38% of score
9 yrs in NPPES registry
- Profile completeness38% of score
100% of core fields populated
- Practice footprint23% of score
2 documented practice locations
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 methodology.
What this provider prescribes (Medicare Part D)
Top drugs by Medicare Part D claim volume, 2024 · 1 distinct drug on file.
| Drug | Part D claims (2024) | Beneficiaries |
|---|---|---|
| Estradiol | 22 | 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.
Practice location
Mailing address
Additional practice locations (1)
- 240 E Huron StSuite 1-200Chicago, IL 60611-2909Phone: (312) 503-7975
Registry dates
- Enumerated
- 2016-08-17
- Last updated
- 2024-11-19
- Certified
- 2024-11-19
Frequently asked questions
- What is Annika Nilsen's NPI number?
- Annika Nilsen's National Provider Identifier (NPI) is 1871048058, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Annika Nilsen's specialty?
- Annika Nilsen is listed in the NPPES registry with a primary specialty of Obstetrics & Gynecology Physician (Allopathic & Osteopathic Physicians).
- Where is Annika Nilsen located?
- Annika Nilsen's practice location on file with NPPES is 680 N Lake Shore Dr Ste 810, Chicago, IL 60611-8700.
- What is Annika Nilsen's phone number?
- The practice phone number listed in the NPPES registry for Annika Nilsen is (312) 926-8811.
- Does Annika Nilsen accept Medicare?
- Annika Nilsen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Annika Nilsen's NPI active?
- Yes — Annika Nilsen's NPI (1871048058) is active in the NPPES registry as of the last update on 2024-11-19.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.