PMP (Project Management Professional)
PMI's flagship. Requires 3+ years experience leading projects + 35 hours of formal PM education + a tough situational exam. Highest signal value in regulated / enterprise / government / construction environments. Less weighted in software-only careers.
CSM (Certified ScrumMaster)
Scrum Alliance, entry-level. Requires a 2-day in-person (or virtual) class + a relatively easy multiple-choice exam. Renewal every 2 years with continuing education + a fee. Useful for early-career signaling; less weighted at senior levels.
PSM (Professional Scrum Master)
Scrum.org, three levels (PSM I / II / III). Harder exam — known for testing actual Scrum understanding, not memorization. No mandatory class and no renewal fee — the PSM I assessment is a one-time $200 fee per attempt (Scrum.org's free "Open" practice assessments are separate). Some hiring managers weight PSM higher than CSM for this reason.
PMI-ACP
PMI's agile cert. Covers Scrum, Kanban, Lean, XP, and others. Useful if you want PMI's brand on your agile knowledge — particularly relevant in orgs running hybrid models that already respect PMI.
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