What the May 2026 Spicer v. McDonough Aggravation Ruling Means for Your Claim

In May 2026, the VA updated its M21-1 adjudication manual to implement the standard set out in Spicer v. McDonough. If you are preparing a secondary or aggravation claim — or you have one pending — this update changes how the VA evaluates the medical evidence connecting your conditions. Here is what the change is, who it applies to, and what it means for the evidence in your file.

The short version

• •Secondary service connection covers conditions caused or aggravated by a condition that is already service-connected (38 CFR § 3.310).
• •Spicer v. McDonough addressed how the VA must evaluate aggravation — the situation where a service-connected condition makes a non-service-connected condition worse.
• •The May 2026 M21-1 update implements the court's framework, including a "but-for" style causation analysis: would the worsening have occurred but for the service-connected condition?
• •Claims decided under the prior standard before the update are evaluated under the rules in effect at the time of the decision — the update applies prospectively to claims adjudicated after it took effect.

What "aggravation" means in a VA claim

VA secondary service connection has always had two pathways under 38 CFR § 3.310:

1. 1.Causation — your service-connected condition caused a new condition. Example: a service-connected knee injury alters your gait for years, and the altered gait causes a hip condition.
2. 2.Aggravation — your service-connected condition made a pre-existing or unrelated condition worse than it would otherwise have been. Example: service-connected PTSD worsens a sleep disorder that originally had a different cause.

Aggravation claims have historically been harder to document than causation claims, because the evidence must distinguish the natural progression of the non-service-connected condition from the additional worsening attributable to the service-connected one.

What Spicer changed

The Spicer decision clarified the causation framework courts and the VA apply when evaluating whether a service-connected condition aggravated another condition. The May 2026 M21-1 update translates that holding into the instructions VA raters follow when they adjudicate these claims.

The practical center of the updated framework is a but-for style question:

Would the claimed worsening have occurred — to the same degree, on the same timeline — but for the service-connected condition?

Under the updated manual provisions, a medical opinion supporting an aggravation claim is evaluated on whether it addresses that question with a reasoned explanation, rather than simply asserting a connection.

What this means for the evidence in your file

This is an evidence-standard change, not a benefits change. It affects what a strong medical opinion needs to address. Based on the updated framework, a medical opinion supporting an aggravation theory is strongest when the records and the opinion together document:

• •A baseline. What was the severity of the non-service-connected condition before the claimed aggravation began? Treatment records establishing a baseline are what make "it got worse" measurable.
• •The worsening. Records showing the condition's progression after the service-connected condition appeared or intensified.
• •The mechanism. A medical explanation of how the service-connected condition produces the worsening — physiological, pharmacological, or behavioral.
• •The but-for analysis. The opinion addresses whether the worsening would have occurred to the same degree without the service-connected condition — distinguishing aggravation from natural progression.

An opinion that says only "condition A aggravates condition B" without reasoning through these elements is the kind of evidence the updated standard is least forgiving of.

Who is protected under the old standard

Claims that were finally decided before the May 2026 update took effect were adjudicated under the manual provisions in effect at the time. The update is applied by raters prospectively — it governs adjudications made after it took effect. If your aggravation claim was granted under the prior framework, the update is not a basis for revisiting that grant.

If your claim was denied before the update and you are considering a supplemental claim, the current standard will apply to the new adjudication — which makes it worth understanding what the but-for framework asks of your evidence before you gather new medical opinions.

Dates that matter

This table describes the general prospective application of manual updates. The controlling rules for any individual claim are determined by the VA — a VSO can review how the timing applies to your specific procedural posture.

The bottom line

If you are building an aggravation claim today, the evidence standard your medical opinions will be measured against is the but-for framework from Spicer, as implemented in the May 2026 M21-1. Documentation that establishes a baseline, shows the worsening, explains the mechanism, and reasons through the but-for question is documentation built to the standard raters now apply.