NATHAN HAMBURGER

NPI 1336300458 · Ophthalmology · Anthem

Provider Status Assessment

Verified Active

Strong multi-source corroboration of active practice across 7 carrier networks with confirmed Colorado DORA license.

Confidence: High

Evidence: 4081 items from 14 sources

Signals: 7 supporting · 0 opposing

Resolution: All evidence sources corroborate active practice. 7 supporting signals with no contradictions across 8 evaluated sources.

Data Source Signals

✓

NPPES

DENVER, 80202

Freshness: Unknown

✓

Network Status

Listed with 7 carriers

anthem_co — in_network (commercial)
uhc_colorado_co — in_network (commercial)
uhc_insurance_co — in_network (commercial)
uhc_services_co — in_network (commercial)
uhc_umr_co — in_network (commercial)
uhc_surest_co — in_network (commercial)
cigna_co — in_network (commercial)

✓

DORA License

Active

✓

Medicare

2,322 services

722 beneficiaries

$173,054.71 total payment

Specialty: Ophthalmology

✗

Care Compare

Address mismatch with NPPES

STEAMBOAT SPRINGS, 80487

✓

PECOS Enrollment

System Reasoning

Claim Under Evaluation

Provider is actively practicing and appropriately listed in carrier networks

Evidence Evaluated

FHIR Directory: No active FHIR endpoint despite carrier listings

NPPES Registry: Active NPI, registered in DENVER

Colorado DORA License: License status: Active

Medicare Billing: 2,322 services, 722 beneficiaries

PECOS Enrollment: Medicare enrollment confirmed

Federal Exclusion Check: No federal exclusions found (OIG LEIE, SAM.gov)

Carrier Networks: Listed in 7 carrier networks

CMS Care Compare: Found in Care Compare with 1 location

Trust Evaluation

identity:0.75Strong

licensure:0.90Strong

activity:1.00

Dimension Scores

Composite0.86

Identity0.75 — Moderate

Active NPI with specialty classification

Licensure0.90 — Strong

Active Colorado DORA license confirmed

Activity1.00 — Strong

Active Medicare billing confirmed

Reachability0.60 — Moderate

Single address source (NPPES)

Network1.00 — Strong

Listed in multiple carrier networks

Why is this provider classified as “verified active”?

Strong multi-source corroboration of active practice. All dimensions above 0.55 with evidence depth ≥ 5. Active license confirmed.

Carrier Network Listings

7 networks across 3 carriers

Strong network presence across 7 carrier networks with corroborating federal activity signals.

Anthem(1 network)

1 DOI 6C-3

Anthem Blue Cross Blue ShieldDOI 6C-3

View carrier →

UnitedHealthcare(5 networks)

1 DOI 6C-34 Federal TiC

UnitedHealthcare of ColoradoDOI 6C-3

View carrier →

UnitedHealthcare InsuranceFederal TiC

View carrier →

UnitedHealthcare ServicesFederal TiC

View carrier →

Related Investigations

All providers in Anthem Blue Cross Blue Shield networkView →All Ophthalmology providers statewideView →All providers in DENVER 80202View →All providers classified as Verified ActiveView →

Known Addresses

NPPESDENVER, 80202

Care CompareSTEAMBOAT SPRINGS, 80487

Evidence

4081 items across 17 assertions from 14 sources

Connected Records

Practice Address

STEAMBOAT SPRINGS, 80487

cms_care_compare, NPPES

Carrier Network Listing

Listed in 7 carrier networks

TiC: Anthem Blue Cross Blue Shield, TiC: UnitedHealthcare Services, TiC: UnitedHealthcare Insurance, TiC: UnitedHealthcare (UMR), TiC: UnitedHealthcare Colorado, TiC: UnitedHealthcare (Surest), TiC: Cigna

Colorado License

Active

DORA

NPI Registration

Status: active

NPPES Deactivation

Order/Referring Eligibility

Record found

cms_order_refer

Medicare Enrollment

Enrolled

PECOS

Medicare Billing

2,322 services

cms_medicare

entity_type

Record found

NPPES

Federal Exclusion Check

No exclusion found

OIG LEIE + SAM.gov

Evidence Lineage

Carrier Network ListingTrust: 0.80

↓TiC: Anthem Blue Cross Blue Shield4029 records ·weight 0.80 · Latest: Mar 14, 2026

Colorado License StatusTrust: 0.95

↓DORA5 records ·weight 0.98 · Latest: Mar 6, 2026

Matched via: license_number

Colorado License StatusTrust: 0.95

↓DORAweight 0.98 · Mar 13, 2026

Matched via: license_number

Carrier Network ListingTrust: 0.80

↓TiC: UnitedHealthcare Services8 records ·weight 0.80 · Latest: Mar 12, 2026

Carrier Network ListingTrust: 0.80

↓

Timeline

Mar 14, 2026Carrier listing: Anthem Blue Cross Blue Shield

Mar 13, 2026DORA license check: Active

Mar 13, 2026DORA license check: Expired

Mar 12, 2026Carrier listing: UnitedHealthcare Services

Mar 12, 2026Carrier listing: UnitedHealthcare Insurance

Mar 12, 2026NPPES record: active

Mar 12, 2026Carrier listing: UnitedHealthcare (UMR)

Mar 12, 2026Carrier listing: UnitedHealthcare Colorado

Mar 11, 2026Carrier listing: UnitedHealthcare (Surest)

Mar 11, 2026Order/Referring Eligibility: record found

Mar 11, 2026

Evidence

Loading evidence lineage...

Disclaimer: This analysis uses publicly available federal and state data sources. It does not constitute a determination of provider status or network participation. Contact the provider or health plan directly to verify current status.

Evidence

4081 items across 17 assertions from 14 sources

Connected Records

Practice Address

STEAMBOAT SPRINGS, 80487

cms_care_compare, NPPES

Carrier Network Listing

Listed in 7 carrier networks

Colorado License

Active

DORA

NPI Registration

Status: active

NPPES Deactivation

Order/Referring Eligibility

Record found

cms_order_refer

Medicare Enrollment

Enrolled

PECOS

Medicare Billing

2,322 services

cms_medicare

entity_type

Record found

NPPES

Federal Exclusion Check

No exclusion found

OIG LEIE + SAM.gov

Evidence Lineage

Carrier Network ListingTrust: 0.80

↓TiC: Anthem Blue Cross Blue Shield4029 records ·weight 0.80 · Latest: Mar 14, 2026

Colorado License StatusTrust: 0.95

↓DORA5 records ·weight 0.98 · Latest: Mar 6, 2026

Matched via: license_number

Colorado License StatusTrust: 0.95

↓DORAweight 0.98 · Mar 13, 2026

Matched via: license_number

Carrier Network ListingTrust: 0.80

↓TiC: UnitedHealthcare Services8 records ·weight 0.80 · Latest: Mar 12, 2026

Carrier Network ListingTrust: 0.80

↓

Timeline

Mar 14, 2026Carrier listing: Anthem Blue Cross Blue Shield

Mar 13, 2026DORA license check: Active

Mar 13, 2026DORA license check: Expired

Mar 12, 2026Carrier listing: UnitedHealthcare Services

Mar 12, 2026Carrier listing: UnitedHealthcare Insurance

Mar 12, 2026NPPES record: active

Mar 12, 2026Carrier listing: UnitedHealthcare (UMR)

Mar 12, 2026Carrier listing: UnitedHealthcare Colorado

Mar 11, 2026Carrier listing: UnitedHealthcare (Surest)

Mar 11, 2026Order/Referring Eligibility: record found

Mar 11, 2026