MARK NATHANSON

NPI 1811998289 · Family Practice · Anthem

Provider Status Assessment

Verified Active

Strong multi-source corroboration of active practice across 9 carrier networks with confirmed Colorado DORA license.

Confidence: High

Evidence: 5405 items from 16 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

AURORA, 80012

Freshness: Unknown

✓

Network Status

Listed with 10 carriers

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

✓

DORA License

Active

✓

Medicare

949 services

201 beneficiaries

$55,099.49 total payment

Specialty: Family Practice

✓

Care Compare

Address matches NPPES

AURORA, 80012

✓

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 AURORA

Colorado DORA License: License status: Active

Medicare Billing: 949 services, 201 beneficiaries

PECOS Enrollment: Medicare enrollment confirmed

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

Carrier Networks: Listed in 10 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

9 networks across 4 carriers

Strong network presence across 9 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 ServicesFederal TiC

View carrier →

UnitedHealthcare of ColoradoDOI 6C-3

View carrier →

UnitedHealthcare InsuranceFederal TiC

View carrier →

Related Investigations

All providers in Anthem Blue Cross Blue Shield networkView →All Family Practice providers statewideView →All providers in AURORA 80012View →All providers classified as Verified ActiveView →

Known Addresses

NPPESAURORA, 80012

Care CompareAURORA, 80012

Evidence

5405 items across 25 assertions from 16 sources

Connected Records

Colorado License

Cancelled

DORA

Practice Address

AURORA, 80012

cms_care_compare, NPPES

Carrier Network Listing

Listed in 9 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, TiC: Kaiser Permanente Insurance Company, TiC: Kaiser Permanente

NPI Registration

Status: active

NPPES Deactivation

Order/Referring Eligibility

Record found

cms_order_refer

Medicare Enrollment

Enrolled

PECOS

Medicare Billing

949 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 Shield5337 records ·weight 0.80 · Latest: Mar 14, 2026

Carrier Network ListingTrust: 0.80

↓TiC: Anthem Blue Cross Blue Shield3 records ·weight 0.80 · Latest: Mar 14, 2026

Colorado License StatusTrust: 0.95

↓DORA7 records ·weight 0.98 · Latest: Mar 13, 2026

Matched via: license_number

Colorado License StatusTrust: 0.95

↓DORA4 records ·weight 0.98 · Latest: Mar 6, 2026

Matched via: license_number

Colorado License StatusTrust: 0.95

Timeline

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

Mar 13, 2026DORA license check: Cancelled

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, 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.

PECOS Enrollment

Medicare enrolled

Order/Referring eligible: Yes

reachability:0.60Moderate

System Determination

Verified Active

Composite score: 0.858

Strong multi-source corroboration of active practice across 9 carrier networks with confirmed Colorado DORA license.

UnitedHealthcare UMRFederal TiC

View carrier →

UnitedHealthcare SurestFederal TiC

View carrier →

Cigna(1 network)

1 DOI 6C-3

CignaDOI 6C-3

View carrier →

Kaiser Permanente(2 networks)

2 DOI 6C-3

Kaiser Permanente Insurance CoDOI 6C-3

View carrier →

Kaiser PermanenteDOI 6C-3

View carrier →

Evidence

5405 items across 25 assertions from 16 sources

Connected Records

Colorado License

Cancelled

DORA

Practice Address

AURORA, 80012

cms_care_compare, NPPES

Carrier Network Listing

Listed in 9 carrier networks

NPI Registration

Status: active

NPPES Deactivation

Order/Referring Eligibility

Record found

cms_order_refer

Medicare Enrollment

Enrolled

PECOS

Medicare Billing

949 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 Shield5337 records ·weight 0.80 · Latest: Mar 14, 2026

Carrier Network ListingTrust: 0.80

↓TiC: Anthem Blue Cross Blue Shield3 records ·weight 0.80 · Latest: Mar 14, 2026

Colorado License StatusTrust: 0.95

↓DORA7 records ·weight 0.98 · Latest: Mar 13, 2026

Matched via: license_number

Colorado License StatusTrust: 0.95

↓DORA4 records ·weight 0.98 · Latest: Mar 6, 2026

Matched via: license_number

Colorado License StatusTrust: 0.95

Timeline

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

Mar 13, 2026DORA license check: Cancelled

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, 2026

weight 0.98 · Mar 13, 2026

Matched via: license_number

Colorado License StatusTrust: 0.95

↓DORAweight 0.98 · Mar 13, 2026

Matched via: license_number

Colorado License StatusTrust: 0.95

↓DORAweight 0.98 · Mar 13, 2026

Matched via: license_number

Colorado License StatusTrust: 0.95

↓DORAweight 0.98 · Mar 13, 2026

Matched via: license_number

Colorado License StatusTrust: 0.95

↓DORAweight 0.98 · Mar 13, 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 Services7 records ·weight 0.80 · Latest: Mar 12, 2026

Carrier Network ListingTrust: 0.80

↓TiC: UnitedHealthcare Insurance4 records ·weight 0.80 · Latest: Mar 12, 2026

NPI Registration StatusTrust: 0.90

↓NPPES Deactivationweight 0.85 · Mar 12, 2026

Carrier Network ListingTrust: 0.80

↓TiC: UnitedHealthcare (UMR)17 records ·weight 0.80 · Latest: Mar 12, 2026

Carrier Network ListingTrust: 0.80

↓TiC: UnitedHealthcare Colorado2 records ·weight 0.80 · Latest: Mar 12, 2026

Carrier Network ListingTrust: 0.80

↓TiC: UnitedHealthcare (Surest)3 records ·weight 0.80 · Latest: Mar 11, 2026

Order/Referring EligibilityTrust: 0.95

↓cms_order_referweight 0.95 · Mar 11, 2026

Carrier Network ListingTrust: 0.80

↓TiC: Cigna5 records ·weight 0.80 · Latest: Mar 11, 2026

Medicare EnrollmentTrust: 0.95

↓PECOSweight 0.95 · Mar 11, 2026

Carrier Network ListingTrust: 0.80

↓TiC: Kaiser Permanente Insurance Companyweight 0.80 · Mar 11, 2026

Practice LocationTrust: 0.85

↓cms_care_compareweight 0.80 · Mar 6, 2026

↓NPPESweight 0.85 · Mar 5, 2026

Medicare Billing ActivityTrust: 0.90

↓cms_medicareweight 0.85 · Mar 6, 2026

Carrier Network ListingTrust: 0.80

↓TiC: Kaiser Permanenteweight 0.80 · Mar 5, 2026

entity_typeTrust: 0.85

↓NPPESweight 0.85 · Mar 5, 2026

Provider SpecialtyTrust: 0.85

↓NPPESweight 0.85 · Mar 5, 2026

Order/Referring Eligibility: record found

Mar 11, 2026Carrier listing: Cigna

Mar 11, 2026Medicare enrollment: Approved

Mar 11, 2026Carrier listing: Kaiser Permanente Insurance Company

Mar 6, 2026Practice address: AURORA, 80012

Mar 6, 2026Medicare billing: 949 services

Mar 5, 2026Carrier listing: Kaiser Permanente

Mar 5, 2026entity_type: record found

Mar 5, 2026Provider Specialty: record found

Mar 5, 2026Practice address: AURORA, 80012