We analyzed written coverage positions for esketamine (Spravato) and other ketamine routes (IV, IM, oral) across Original Medicare (national program), all regional Medicare Administrative Contractors (MACs), and Medicare Advantage (MA) parent groups, enrollment-weighted to August 2025 (30,786,085 MA lives). As verified August 31, 2025, Original Medicare and every MAC publish no affirmative coverage policy (“Not Stated”) despite existing HCPCS G-codes for Spravato visits (G2082, G2083). In MA, ~36.5% of enrollment (≈11.3M) is in plans that explicitly cover Spravato (~33.5% with prior authorization; ~3.1% without), while ~63.5% (≈19.5M) is “Not Stated.” For non-Spravato routes, “Not Stated” predominates with notable explicit exclusions (especially IV). Implications for Medicare beneficiaries: policy silence in Original Medicare and MACs pushes claims into case-by-case review, making access contingent on documentation, local reviewer discretion, and persistence—slowing or blocking a fast-acting therapy for treatment-resistant depression. Implications for Medicare Advantage enrollees: only about one in three has a posted pathway (usually with prior authorization); for the majority under “Not Stated,” plans typically default to non-coverage unless an exception is won. In practice, “Not Stated” functions as a barrier to transparency, increasing delays, denials, and abandonment risk. Conclusion: coverage clarity—not merely the existence of billing codes—governs real-world access; eliminating “Not Stated” and standardizing prior-authorization criteria would materially reduce inequities and time-to-first-dose.