If a vet's claim for sleep apnea because of sinusitis was denied, and now they want to claim sleep apnea as being caused by their service-related PTSD, is this treated as a brand-new claim for sleep apnea, or is it considered a supplemental?
If it's been over a year since the first claim, it'll be considered supplemental because it's been claimed before. If it's within a year, you can choose between supplemental or higher level review.
Send in a supplemental claim with a letter that explains your new reason for thinking it's related to your service. Of course, you need a nexus letter that clearly explains the medical reasons.
