Gregg Nielsen, D.C.
NPI 1689623423 · Chiropractor · Waterford, WI
Enrolled with Medicare as Practitioner - Chiropractic · source: CMS PECOS Public Provider Enrollment (2026.04.01)
Gregg Nielsen, D.C. is a Chiropractor provider in Waterford, WI (NPI 1689623423).
Provider details
- NPI number
- 1689623423
- Entity type
- Individual
- Primary specialty
- ChiropractorChiropractic Providers
- Credential
- D.C.
- Sex
- Male
- License
- 1969 (WI)
Specialties & taxonomies
Chiropractic Providers
Profile Score
A profile completeness & documented-activity index — NOT a quality, outcomes, or patient-satisfaction rating.
- Registry tenure28% of score
20 yrs in NPPES registry
- Profile completeness28% of score
100% of core fields populated
- Practice footprint17% of score
1 documented practice location
- Medicare service volume (vs. specialty peers)28% of score
122 Medicare services, 2024 (ranked within specialty)
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 methodology.
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) |
|---|---|---|
| Chiropractic Manipulative Treatment, 1-2 Spinal Regions98940 | 122 | $25 |
Typical Medicare-allowed amounts for these services range $25–$25 (2024). The Medicare-allowed amount is what Medicare recognizes for a service under fee-for-service — a reference figure for 2024, not a price quote and not what you would be billed. Medicare Part B covers roughly an eighth of all NPIs (65+ skew); services with fewer than 11 beneficiaries are suppressed by CMS. Source: CMS Medicare Physician & Other Practitioners, by Provider & Service.
Practice location
Mailing address
Registry dates
- Enumerated
- 2006-05-09
- Last updated
- 2007-07-08
Frequently asked questions
- What is Gregg Nielsen's NPI number?
- Gregg Nielsen's National Provider Identifier (NPI) is 1689623423, a unique 10-digit ID issued by CMS for use in standard healthcare transactions.
- What is Gregg Nielsen's specialty?
- Gregg Nielsen is listed in the NPPES registry with a primary specialty of Chiropractor (Chiropractic Providers).
- Where is Gregg Nielsen located?
- Gregg Nielsen's practice location on file with NPPES is 505 Aber Dr, Waterford, WI 53185-4401.
- What is Gregg Nielsen's phone number?
- The practice phone number listed in the NPPES registry for Gregg Nielsen is (262) 534-3767.
- Does Gregg Nielsen accept Medicare?
- Gregg Nielsen is approved to bill Medicare according to CMS PECOS enrollment data (2026.04.01). Confirm current participation with the provider before scheduling.
- Is Gregg Nielsen's NPI active?
- Yes — Gregg Nielsen's NPI (1689623423) is active in the NPPES registry as of the last update on 2007-07-08.
Source: CMS NPPES Data Dissemination (June 2026). NPI Central is not affiliated with CMS. Data is provided as-is from the public registry.