PubMed vs PubMed Central: How to Get Free Full-Text Medical Papers
The difference between PubMed and PubMed Central, what PMID and PMCID numbers mean, and how to find the free full text of a medical or life-science paper.
PubMed and PubMed Central sound like the same thing and are run by the same organisation, the US National Library of Medicine. They do different jobs. One helps you find a paper; the other lets you read it.
PubMed is the index
PubMed is a free search engine covering tens of millions of articles in medicine and the life sciences. For each one it holds the citation and usually the abstract, but not the full text. A PubMed record tells you a paper exists and what it found in summary, then links out to wherever the full article lives. That may be a paywalled publisher page.
PubMed Central is the library
PubMed Central, usually shortened to PMC, is a free archive of complete articles. It holds millions of them. Everything in PMC can be read in full by anyone, without an account.
Papers arrive in PMC in two main ways. Many journals deposit all of their articles. And research funded by the US National Institutes of Health must be deposited there by the authors. For papers accepted since July 2025, that copy has to be available as soon as the paper is published; before then, a delay of up to twelve months was allowed.
PMID and PMCID
- A PMID is the number PubMed gives every record, such as 21376230. Having a PMID says nothing about whether the paper is free.
- A PMCID starts with the letters PMC, such as PMC4221854. A paper has one only if its full text is in PubMed Central, so a PMCID means a free copy exists.
Most papers also have a DOI, explained in what a DOI is and where to find it.
How to find the free full text
From a PubMed record
Look at the top right of the page for the full-text links. A button for PMC, or a "Free PMC article" label on the search result, means the full text is free in PubMed Central. A "Free article" label means the publisher itself makes it free.
From a PubMed search
In the filters beside the results, tick Free full text. The list then shows only papers you can read in full.
When PubMed shows no free link
PubMed only knows about PMC and the publisher. A free copy may still exist somewhere else, such as a university repository or a preprint server like bioRxiv or medRxiv. Paste the PubMed link, the DOI or the title into the finder on our home page, which checks those other sources as well.
Europe PMC
Europe PMC is a partner archive run from Europe. It contains the PubMed Central articles along with preprints and other material, and has its own search. If you are looking for life-science papers it is worth knowing as a second place to search.
Where this leaves you
For medicine and biology, PMC is the single biggest source of legal free papers, and its coverage of recent research is growing because of funder rules. When a paper is not there, the routes in our guide to reading research papers for free still apply, starting with asking the author.
Find a free copy of a paper
Paste a DOI, a link to the paper or its title, and we will look for a free, legal copy. No signup.
Frequently asked questions
Is PubMed free?
Searching PubMed and reading abstracts is free. Whether you can read the full article depends on the paper: it is free if it is in PubMed Central or the publisher makes it open.
What is the difference between a PMID and a PMCID?
A PMID identifies a record in PubMed, which every indexed paper has. A PMCID identifies a full-text article in PubMed Central, so only papers that are free to read there have one.
Why can I see the abstract but not the paper?
PubMed holds abstracts, not full articles. If the paper is not in PubMed Central and the publisher charges for it, PubMed can only link you to the paywalled page.