When a client sells into providers or payers, Definitive Healthcare is the source we reach for. It is a healthcare commercial intelligence platform that maps hospitals, physician groups, clinics, payers, and individual providers across a fragmented market. Generic B2B databases miss how this world works. Definitive attaches claims data, affiliations, technology installs, and financials to each record, combining claims feeds, public filings, surveys, and proprietary research into deep, accurate profiles. The segmentation reflects clinical reality. You search and filter by specialty, procedure volume, location, technology, or buying signal, so targeting matches how providers actually operate rather than a flat firmographic guess that misses the context. We treat it as the source of truth for healthcare-focused accounts, but only when a client genuinely sells into that market. For those engagements, we pull a segmented list and push it into Clay to layer in buying-committee contacts. After verification, we build sequenced outbound around each account's actual claims and affiliation profile. The data also feeds CRM and territory planning, and modular dataset add-ons let us pull only the slices a given client needs. The message lands with real clinical and financial context, which is the whole reason we reach for a specialist source on these accounts instead of leaning on a general firmographic database that would miss it.