Convert Between PMID, PMCID, and DOI

Enter a PubMed ID (PMID), PubMed Central ID (PMCID), or DOI. Get the other two identifiers instantly.

Enter an identifier

We’ll look up the other identifiers via the NCBI ID Converter. Nothing is stored.

What are PMID, PMCID, and DOI?

These three identifiers each point to a scholarly publication, but they come from different systems and serve different purposes:

PMID (PubMed ID) - a numeric identifier assigned by the US National Library of Medicine to every record in the PubMed citation database. Example: 36859578.
PMCID (PubMed Central ID) - identifies the full-text article in PubMed Central, the open-access repository operated by the NIH. Always starts with PMC followed by digits. Example: PMC9977688.
DOI (Digital Object Identifier) - assigned by CrossRef or other registration agencies to uniquely identify a publication at the publisher level. Always starts with 10.. Example: 10.1038/s41586-023-05881-4.

A single paper can have all three - a DOI from the publisher, a PMID from PubMed, and a PMCID from PubMed Central. But not every paper has all three: a PMCID only exists if the full text has been deposited in PMC.

Why do you need to convert between them?

NIH grant applications require PMCID for all cited publications covered by the NIH Public Access Policy. If you only have the DOI or PMID, you need the PMCID.
Reference lists in journal submissions typically use DOIs. If your source database gave you a PMID, you need to convert.
Database searches use PMID (PubMed) or DOI (CrossRef, publisher sites). Converting lets you cross-reference the same paper across systems.
Compliance reporting for funders (NIH, Wellcome, UKRI) often requires specific identifier types. This tool saves a trip to the NCBI website.

When is a mapping not available?

Not every paper has all three identifiers:

No PMCID - the full text has not been deposited in PubMed Central. This is common for papers behind a paywall or from publishers who do not participate in PMC. The NIH Public Access Policy requires deposit for NIH-funded work, but not all papers are NIH-funded.
No DOI - older papers, especially those published before DOIs became standard (roughly pre-2000), may not have one. Some smaller publishers still do not register DOIs.
No PMID - the paper is not indexed in PubMed. PubMed primarily covers biomedical and life sciences; papers outside these fields may have a DOI but no PMID.

When a mapping is not available, the tool shows “Not available” for that identifier. This does not mean the identifier you entered is invalid - it means the corresponding record does not exist in the NCBI system.

Frequently asked questions

Can I convert multiple identifiers at once?

Not yet - this tool handles one identifier at a time. For batch processing, use the Scholar Sidekick API directly.

Where does the data come from?

This tool uses the NCBI ID Converter API, a free, public service provided by the US National Library of Medicine. The same API powers the NCBI’s own ID converter tool.

Is this tool free?

Yes. No account required. Nothing you enter is stored.

Related tools

What are PMID, PMCID, and DOI?

These three identifiers each point to a scholarly publication, but they come from different systems and serve different purposes:

PMID (PubMed ID) - a numeric identifier assigned by the US National Library of Medicine to every record in the PubMed citation database. Example: 36859578.

PMCID (PubMed Central ID) - identifies the full-text article in PubMed Central, the open-access repository operated by the NIH. Always starts with PMC followed by digits. Example: PMC9977688.

DOI (Digital Object Identifier) - assigned by CrossRef or other registration agencies to uniquely identify a publication at the publisher level. Always starts with 10.. Example: 10.1038/s41586-023-05881-4.

Why do you need to convert between them?

NIH grant applications require PMCID for all cited publications covered by the NIH Public Access Policy. If you only have the DOI or PMID, you need the PMCID.

Reference lists in journal submissions typically use DOIs. If your source database gave you a PMID, you need to convert.

Database searches use PMID (PubMed) or DOI (CrossRef, publisher sites). Converting lets you cross-reference the same paper across systems.

Compliance reporting for funders (NIH, Wellcome, UKRI) often requires specific identifier types. This tool saves a trip to the NCBI website.

When is a mapping not available?

Not every paper has all three identifiers:

No PMCID - the full text has not been deposited in PubMed Central. This is common for papers behind a paywall or from publishers who do not participate in PMC. The NIH Public Access Policy requires deposit for NIH-funded work, but not all papers are NIH-funded.

No DOI - older papers, especially those published before DOIs became standard (roughly pre-2000), may not have one. Some smaller publishers still do not register DOIs.

No PMID - the paper is not indexed in PubMed. PubMed primarily covers biomedical and life sciences; papers outside these fields may have a DOI but no PMID.

Frequently asked questions

Can I convert multiple identifiers at once?

Not yet - this tool handles one identifier at a time. For batch processing, use the Scholar Sidekick API directly.

Where does the data come from?

This tool uses the NCBI ID Converter API, a free, public service provided by the US National Library of Medicine. The same API powers the NCBI’s own ID converter tool.

Is this tool free?

Yes. No account required. Nothing you enter is stored.