Generally only through guaranteed issue. Continuous supplemental oxygen is treated as a marker of advanced disease and appears as a knockout question on most simplified issue applications.
Oxygen changes the question from which rate class to which product, and it does so more decisively than almost anything else on an application.
Why it carries so much weight
Home oxygen is prescribed when the lungs can no longer maintain adequate blood oxygen unaided. Across the market it is read as a marker of advanced disease rather than as one factor among several, and it is one of the small number of items that appears as a direct knockout question — alongside dialysis, terminal diagnosis and nursing home confinement.
Nocturnal-only oxygen is sometimes viewed less severely, and it is worth stating precisely which you use rather than answering the question generically.
What remains open
Guaranteed issue asks no health questions at all, so oxygen does not disqualify you. Expect small face amounts, level premiums, permanent cover, and a graded death benefit for the first two or three years.
Final expense products cover similar ground and are designed for exactly this purpose — funeral and final bills rather than income replacement.
Two things to check first
Any existing policy may have an accelerated death benefit rider allowing part of the benefit to be drawn early. And employer group cover is issued without individual underwriting, so it may already be available to you without any of this applying.
The full treatment of this topic is on COPD and respiratory.