How EmailAddress.ai Sources, Verifies, and Refreshes Data
The full sourcing, verification, and refresh playbook behind our HCP and B2B contact databases.
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Database overview: current counts
All figures from March 2026 delivery. Updated on each scheduled refresh cycle.
Most data vendors claim accuracy. Few publish the methodology behind it. This page documents exactly how EmailAddress.ai builds, verifies, and maintains its healthcare professional and B2B contact databases, the sources we use, the verification steps each record passes through, the fields we cover, and how often the data is refreshed.
EmailAddress.ai verifies healthcare and B2B contact data through a 4-stage process: multi-source ingestion from 20+ verified regional sources, NPI cross-matching for healthcare professionals, email deliverability verification using our own catch-all verification engine, and Monthly Refresh cycles for both HCP and B2B data.
| Dataset | Total Records | Last Refreshed | Next Refresh |
|---|---|---|---|
| HCP + Nurses | 5,670,516 | March 2026 | September 2026 |
| Healthcare Executives | 2,504,942 | March 2026 | September 2026 |
| USA B2B | 76,236,695 | March 2026 | June 2026 |
| UK + Ireland B2B | 5,351,497 | March 2026 | June 2026 |
| Canada B2B | 1,611,494 | March 2026 | June 2026 |
HCP data: sourcing methodology
Source architecture
The EmailAddress.ai HCP database is built from 20 verified regional sources. No single source contributes more than 35% of the total dataset. This multi-source architecture is the primary reason our data stays current when competitors with single-source NPI-only extracts fall behind.
Primary sources used:
- CMS National Provider Identifier (NPI) registry, used for physician identity verification and specialty classification, not as a primary contact source
- State medical and nursing licensing boards across all 50 states
- Professional association membership directories (specialty societies, nursing organizations, pharmacy boards)
- Hospital and health system provider directories (publicly accessible)
- Group practice and clinic directories
- Proprietary opt-in networks for supplemental email verification
What NPI covers and what it does not. The NPI registry is the most reliable physician identity source in the US, but it does not contain verified email addresses, it updates quarterly, and it does not track practice affiliation changes in real time. EmailAddress.ai uses NPI as a verification anchor, not a primary contact source.
HCP specialty depth
The database spans 39 specialty groups and 909 sub-specialty categories. Coverage is not uniform across all specialties, contact volume reflects the size of each specialty population in the US. Exact counts by specialty are published on our physician email data page.
HCP data: verification process
Every record in the HCP database passes through four verification stages before delivery.
Entity resolution and deduplication
Incoming records from multiple sources are matched against each other using a combination of NPI (where available), name, credential, and practice address. Duplicates across sources are merged into a single master record, retaining the highest-confidence data from each source for each field.
NPI cross-matching
Records for physicians, nurse practitioners, physician assistants, CRNAs, and other licensed practitioners are matched against the current CMS NPI registry file. Records that match an active NPI are flagged as NPI-verified. Records that cannot be matched are placed in a secondary review queue.
NPI coverage in current dataset: 2,587,330 records (45.6% of the 5,670,516 HCP total). The remaining records are allied health professionals, executives, and credential types for which NPI is not issued, not unverified physician records.
Email deliverability verification
Every email address in the HCP dataset passes through EmailAddress.ai's own email verification engine.
- Domain and MX record validation
- SMTP handshake verification
- Catch-all domain detection and resolution, hospital and group practice email systems frequently operate as catch-all domains, which most verification tools mark as "risky" and skip. Our engine applies additional resolution steps to determine actual deliverability status.
- Role address and shared mailbox detection
- Suppression against known hard bounce and spam trap lists
Addresses that fail verification are removed from the delivered dataset. Addresses that pass catch-all resolution but cannot be fully verified are flagged in the delivery file so clients can apply their own risk threshold.
Field-level quality scoring
In addition to email verification, each record is scored for completeness across 12 key fields. Records with incomplete or inconsistent field data are flagged for review before inclusion in delivery.
HCP field coverage: March 2026
The following fill rates apply to the current HCP + Nurses dataset (5,670,516 records).
| Field | Records with Data | Fill Rate |
|---|---|---|
| Name (first, last) | 5,670,516 | 100% |
| Email address | 5,670,516 | 100% |
| Specialty | 5,670,516 | 100% |
| Country | 5,670,516 | 100% |
| Address / City / ZIP | 5,659,034+ | ~99.8% |
| Phone number | 5,422,045 | 95.6% |
| Hospital / Clinic name | 4,902,606 | 86.5% |
| Gender | 4,886,940 | 86.2% |
| Web address | 3,844,125 | 67.8% |
| NPI number | 2,587,330 | 45.6% |
| State license number | 1,834,216 | 32.3% |
| FAX number | 1,193,819 | 21.1% |
Why we publish this table. Most data vendors publish headline accuracy numbers and nothing else. Publishing field-level fill rates tells you which fields are reliable enough to use in segmentation and which are supplementary. Build your campaign segmentation on 100% coverage fields. Use NPI and state license for verification matching, not filtering.
HCP data: refresh schedule
Healthcare professional data decays faster than most B2B data. Physician contact information changes when practitioners retire, relocate, change practice affiliation, gain new specialty certifications, or transition from employed to independent practice.
The March 2026 delivery reflects records verified as of March 31, 2026. The next scheduled full refresh is September 2026.
B2B data: sourcing and verification
Source architecture
The EmailAddress.ai B2B database is built from 43 verified global sources, delivering 99.3% accurate, multi-source enrichment. Sources include business registries, professional network feeds, company directory databases, event attendee data, and opt-in newsletter and publication networks. No single source drives more than 30% of any regional dataset.
Geographic coverage
B2B email verification
B2B email addresses pass through the same 4-step deliverability verification process as HCP data. The USA dataset delivers 98.2% email coverage against the total contact count, with 97% job title coverage and 84.6% NAIC industry classification.
B2B refresh schedule
B2B contact data is refreshed monthly. The March 2026 delivery is the current version. The next scheduled refresh is April 2026.
B2B field coverage: March 2026
USA B2B (base: 76,236,695)
| Field | Records | Fill Rate |
|---|---|---|
| Name + Company | 76,236,695 | 100% |
| Professional email | 74,832,697 | 98.2% |
| Job title | 73,964,466 | 97.0% |
| Industry (NAIC) | 64,473,684 | 84.6% |
| Employee count | 61,617,600 | 80.8% |
| Company website | 50,875,743 | 66.7% |
| LinkedIn URL | 43,231,724 | 56.7% |
| Office phone | 43,198,688 | 56.7% |
| Company revenue | 33,577,990 | 44.0% |
Healthcare executives: separate dataset
The healthcare executive database (2,504,942 contacts) is sourced and maintained separately from the HCP clinical dataset. Sources include health system and hospital leadership directories, professional association officer records, and business registry filings.
Field coverage: 95.3% job title, 81.6% company website, 76.7% office phone, 75.4% LinkedIn, 74% employee data, 66.9% company revenue.
How we approach compliance in data collection
Every dataset delivered by EmailAddress.ai is accompanied by lawful-basis documentation covering the applicable compliance frameworks for the geographic scope of the license.
GDPR (EU practitioners), CCPA (California), and HIPAA-adjacent data handling. No patient data, no clinical records, no prescribing history.
GDPR (EU records), CCPA (California records), and CAN-SPAM compliance documentation for US records.
We do not guarantee compliance for the buyer's specific use case, compliance is use-case dependent. We provide the documentation and framework; buyers are responsible for their own compliance obligations.
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