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Short answer: PMID stands for PubMed Identifier (also written PubMed ID). It is the number PubMed assigns to each citation in its database, for example 17170002. This page explains what the number identifies, how to search by it, and how it differs from a PMCID, a DOI and an NIHMS ID.
What does PMID stand for, and what is a PubMed ID?
PMID is short for PubMed Identifier. PubMed is a free resource, developed and maintained by the National Center for Biotechnology Information (NCBI) at the National Library of Medicine (NLM), part of the US National Institutes of Health. Its help page describes the PMID as a “unique number assigned to each PubMed citation.” (PubMed Help, pubmed.ncbi.nlm.nih.gov/help/, read 2026-11-07.)
The PMID names a citation record in PubMed, not the article’s full text and not the journal. The same article can have a DOI from its publisher, a PMID from PubMed, and, if a copy is deposited in PubMed Central, a PMCID. Each one points at a different record in a different system.
What a PMID is, and what it is not
- Stable. PubMed states that PMIDs “do not change over time or during processing and are never reused,” so a PMID in a reference list or spreadsheet keeps pointing at the same citation.
- Not a quality mark. The number identifies a citation in PubMed. It does not tell you whether the article was peer reviewed, and PubMed’s help page does not present it that way. Peer review is a property of the journal’s process; see peer review and the journal’s own policy pages.
- Not a DOI. A DOI is registered by the publisher or a registration agency and resolves to the article through the DOI system. A PMID exists only inside PubMed and its linked NCBI tools.
- Not a PMCID. The PMC field in PubMed holds the “unique identifier for the cited article in PubMed Central (PMC),” written with a prefix such as PMC2600426.
PMID format and example
A PMID is a plain number with no prefix. The PubMed help page uses 17170002 and 16381840 as examples. Many databases and reference managers store the PMID in its own field so that records can be matched and de-duplicated by number.
How to find an article by PMID, or a PMID for an article
Search by PMID
Per the PubMed help page, you can enter the ID with or without the search field tag [pmid]. To search several at once, separate the numbers with a space (for example, 17170002 16381840); PubMed combines them with OR. To combine a PMID with other terms, the tag is required, as in lipman AND 16381840[pmid].
Find the PMID when you only have a citation
- Click Single Citation Matcher on the PubMed homepage. NLM describes it as a fill-in-the-blank form for searching when you have some bibliographic information such as journal name, volume or page number.
- Enter the citation information you have.
- Click Go. The PMID is shown on the citation’s record.
Convert between PMID, PMCID and NIHMS ID
PubMed help points to the PMID/PMCID/NIHMSID Converter for converting IDs of publications referenced in PubMed and PMC. To retrieve PubMed citations that include an NIHMS ID, the help page gives the query hasnihmsid.
PMID, PMCID and DOI compared
| Identifier | What it identifies | Where it lives | How PubMed help says to search it |
|---|---|---|---|
| PMID | A citation in PubMed | PubMed (NCBI/NLM) | Number, with or without [pmid] |
| PMCID | An article in PubMed Central | PubMed Central | Prefix plus number, e.g. PMC2600426 |
| NIHMS ID | A manuscript record linked to PubMed citations | Linked from PubMed | hasnihmsid retrieves citations that have one |
| DOI | The published article, assigned through the DOI system | The DOI system | Not a PubMed identifier |
For deeper contrasts, see PMID vs PMCID, PMID vs DOI and PubMed vs PubMed Central.
Where PMIDs are used
PubMed holds more than 40 million citations and abstracts of biomedical literature, according to its About page (read 2026-11-07). Because the number is stable, it is a convenient key for citing an article unambiguously, linking records between systems, and matching entries in reference managers. A PMID is one kind of persistent identifier in the wider scholarly infrastructure, alongside DOIs and ORCID iDs for people.
Common problems
- No PMID for a record you expect. A PMID exists only for items that are citations in PubMed. Search the title in PubMed or use Single Citation Matcher.
- Mixing up PMID and PMCID. The PMCID carries the PMC prefix; searching a PMCID as a PMID, or the reverse, returns the wrong record or nothing.
- Combining a PMID with other terms without the tag. Use
[pmid]when the number sits inside a longer query. - Expecting full text. PubMed contains citations and abstracts, not full text, though links to full text are often provided. A full-text journal site may require a fee or subscription; the Free full text filter narrows results to resources available free on the web, including PubMed Central.
FAQ
What is a PMID?
A PMID is the unique number PubMed assigns to each citation in its database. It never changes and is never reused.
What does PMID stand for?
PubMed Identifier, also called PubMed ID.
Is PubMed a free resource?
Yes. NLM describes PubMed as a free resource supporting the search and retrieval of biomedical and life sciences literature. Access to an article’s full text on a publisher’s site may still require a fee or subscription.
Are DOI and PMID the same?
No. A DOI is assigned through the DOI system and identifies the published article; a PMID is assigned by PubMed to its own citation record. One article can have both. See PMID vs DOI.
Which is better, Scopus or PubMed?
They are different databases rather than ranked alternatives. PubMed is free and covers biomedical and life sciences literature (including MEDLINE, PubMed Central and Bookshelf content); Scopus is a separate abstract-and-citation database. Which one suits you depends on the subject area and the access your institution provides.
How do I find peer-reviewed articles?
A PMID does not signal peer review. Check the journal’s own editorial policy for how it reviews submissions.
Sources
- PubMed Help, National Library of Medicine: pubmed.ncbi.nlm.nih.gov/help/ (read 2026-11-07).
- About PubMed, National Library of Medicine: pubmed.ncbi.nlm.nih.gov/about/ (read 2026-11-07).
