How to read an NPI record

A National Provider Identifier is a ten-digit number issued to healthcare providers in the United States. Anyone who bills insurance needs one, which makes the registry close to a complete census of practising providers — and it is published in full, monthly, for anyone to download.

Every provider page on this site is built from one such record. Here is how to read one.

The fields, and what they are worth

NPI — the ten-digit number. Issued once, never reused, never changes. It is the only truly stable identifier: names change, addresses change, the number does not. If you want to be certain you have the right person, this is the field to match on. You can look any NPI up yourself at the official registry search.

Entity type. Type 1 is an individual, Type 2 is an organisation. This site indexes Type 1 only, so every listing here is a person rather than a clinic.

Name and credentials. The legal name plus a free-text credential field the provider fills in themselves. Free text is why you will see LCSW, L.C.S.W. and LCSW-C all meaning much the same thing.

Taxonomy code. The most useful field, and the one nobody recognises. It is a standardised classification — 1041C0700X is Clinical Social Worker, 103TC0700X is Clinical Psychologist, 225100000X is Physical Therapist. A provider may list up to fifteen, with one flagged primary. This is what our licence-type counts are built on, because unlike the free-text credential it is a controlled vocabulary.

Practice location address and phone. Self-reported by the provider as the place patients can find them.

Licence number and state. The state that issued the licence. Note this is not always the state of the practice address — a provider may be licensed in one state and practising in another, or hold several.

Enumeration date. When the NPI was first issued.

Sole proprietor flag. Whether the provider registered as a sole proprietor — a rough hint at solo practice versus employment.

The three fields people misread

Enumeration date is not “years of experience.” It is when the provider first registered with the federal system. Someone who practised for fifteen years before NPIs were introduced, or who worked in a setting that did not bill insurance, will show a much later date than their career would suggest. It is a floor, not a measure.

The address is not verified. It is what the provider typed, updated when they get around to it. Some are years out of date. Some solo practitioners register a home address, which is why this site shows an approximate ZIP-code area on provider pages rather than a pin — see our methodology.

“Registered” is not “licensed and practising.” This is the big one. An NPI is issued once and persists. Nothing in the registry is updated when a licence lapses, is suspended, or the provider retires. A record here means someone registered — not that they are currently authorised, currently working, or currently taking clients. Only the state board can confirm the licence: how to verify it.

What is not in the record at all

No fees. No insurance networks. No availability. No specialisms beyond the taxonomy code. No approach, no languages, no ratings. See why no directory can tell you who is accepting clients.

Deactivated records

NPIs can be deactivated — on death, retirement, or at the provider’s request. Deactivated records remain in the file with a deactivation date. We exclude them, so a provider who has formally deactivated will not appear here. Most people who stop practising never bother to deactivate, which is precisely why “registered” and “practising” are different things.

Looking one up yourself

Everything on this site is derived from public data you can query directly. The NPPES registry search takes a name, a number or a location, and returns the raw record. If a page here looks wrong, that is the authoritative source to check it against — and if it is your own record that is wrong, that is also where you correct it, since we copy it and cannot change it.

If you would rather not appear here at all, removal is unconditional and takes effect on the next build.