Is the Journal of Participatory Medicine (JoPM) in PubMed/PMC yet?

Not yet (as of Jan 2018). An application is pending, and (if accepted) it will then be indexed retrospectively from article e13 in 2017 onwards (which is when JMIR Publications took over, see JoPM journal history).

If you are an author you can also submit your manuscript (post-acceptance or post-publication) to PMC as author-manuscript, if you require a PubMed-indexing and/or PMCID immediately (some funders require this under various open access mandates). It will then be in PubMed Central as well as in PubMed.

Submit accepted or final manuscript at:

• NIHMS (PMC Submission system, external link)

Related:

• Why does my article not have a PMCID yet? 
• Which JMIR journals are currently free to publish in?