Secondary OSA denial and appeal question (baseline?)

I was denied for a primary and secondary connection for OSA. I have a current diagnosis of OSA, and I am prescribed a CPAP. I was not diagnosed in service.

The denial letter states that "In accordance with 38 CFR 3.310(b), if no baseline can be established, no aggravation can be demonstrated. When a baseline cannot be established, a claim based on aggravation of an NSC disability by an SC disability must be denied. (38 CFR 3.310; OFO Guidance: Spicer Allen Aggravation, April 22, 2026).

My questions are:

1. How and should I appeal this decision? If so, with a supplemental or HLR?

2. What evidence is the VBA asking for or looking for?

3. Is my baseline entering the service healthy and OSA-free?

-If so, this should be reflected in my entry paperwork from MEPS.

I did not enter service with OSA and only developed it and was diagnosed when I got out. I had a doctor review my medical records and submit a DBQ and Nexus letter.

I feel like I'm right on the cusp of an approval, and I would appreciate any guidance.

Here is the denial letter:

Service connection for sleep apnea as secondary to the service-connected disability of

posttraumatic stress disorder (PTSD) with major depressive disorder & alcohol use

disorder and chronic pain.

A claimant may file a supplemental claim by submitting or identifying new and relevant

evidence. New evidence is evidence not previously part of the actual record before agency

adjudicators. Relevant evidence means evidence that tends to prove or disprove a matter at issue

in a claim. (38 CFR 3.2501) In support of your claim, new and relevant evidence has been

received, and your claim is now reconsidered.

The evidence does not support a change in our prior decision. Therefore, we are confirming the

previous denial of this claim. The medical records fail to provide any evidence which would

warrant any change in the previous decision. Service connection for this condition remains

denied as the evidence continues to show this condition was not incurred in or aggravated by

military service. (38 CFR 3.303, 38 CFR 3.304, 38 CFR 3.306)

We received a private DBQ with medical opinion that was positive as secondary to the service-connected disability of posttraumatic stress disorder (PTSD) with major depressive disorder &

alcohol use disorder and chronic pain from service-connected musculoskeletal conditions

(bilateral knee and hip conditions) with weight gain as an intermediate step. However, no

baseline is established, and service connection cannot be granted.

A baseline level of severity cannot be established due to insufficient medical evidence.

Under Allen, SC may be granted when a SC disability aggravates an NSC condition. Although a

baseline is no longer required prior to requesting an NSC aggravation examination, a baseline is

still required to grant SC on the basis of NSC aggravation and to determine the degree of

disability subject to SC. (OFO Guidance: Spicer Allen Aggravation, April 22, 2026)

In accordance with 38 CFR 3.310(b), if no baseline can be established, no aggravation can be

demonstrated. When a baseline cannot be established, a claim based on aggravation of an NSC

disability by an SC disability must be denied. (38 CFR 3.310; OFO Guidance: Spicer Allen

Aggravation, April 22, 2026)

Favorable Findings identified in this decision:

Participation in a toxic exposure risk activity is conceded. Your service personnel record shows

service in Southwest Asia.

The claimed issue has been permanently aggravated beyond natural progression by a service-connected disability.

You have been diagnosed with a disability. Your sleep apnea DBQ exam shows a diagnosis of

sleep apnea.

The claimed primary disability is service-connected. You are service-connected for posttraumatic

stress disorder (PTSD) with major depressive disorder & alcohol use disorder, bilateral hip

conditions, and bilateral knee conditions.