diff --git a/src/bin/alpha_id.rs b/src/bin/alpha_id.rs
index ad12468..af2cb0a 100644
--- a/src/bin/alpha_id.rs
+++ b/src/bin/alpha_id.rs
@@ -1,4 +1,3 @@
-use alpha_id::eval::{inject_errors, recall_at_k};
 use alpha_id::model::{Config, Filter, Mode};
 use alpha_id::pipeline::Pipeline;
 use clap::{Parser, Subcommand};
@@ -36,6 +35,27 @@ enum Cmd {
     },
 }
 
+fn run_eval(p: &Pipeline, m: Mode, cases: usize, seed: u64) -> (f64, f64) {
+    use alpha_id::eval::{inject_errors, recall_at_k};
+    use alpha_id::model::Filter;
+    let billable: Vec<_> = p.entries.iter().enumerate()
+        .filter(|(_, e)| e.valid)
+        .filter(|(_, e)| alpha_id::corpus::primary_code(e)
+            .and_then(|c| p.meta.get(c))
+            .map(|mt| mt.para295 == "P").unwrap_or(false))
+        .take(cases).collect();
+    let mut sum = 0.0;
+    for (k, (_, e)) in billable.iter().enumerate() {
+        let code = alpha_id::corpus::primary_code(e).unwrap().to_string();
+        let noisy = inject_errors(&e.text, 0.15, seed.wrapping_add(k as u64));
+        let res = p.suggest(&noisy, m, &Filter::default(), 10);
+        let preds: Vec<String> = res.suggestions.iter().map(|s| s.icd_code.clone()).collect();
+        sum += recall_at_k(&preds, &code, 10);
+    }
+    let n = billable.len().max(1) as f64;
+    (sum / n, sum / n)
+}
+
 fn read_input(arg: &str) -> String {
     if let Ok(v) = std::env::var("ALPHA_ID_STDIN") { return v; }
     if arg == "-" {
@@ -115,31 +135,17 @@ fn main() {
             }
         }
         Cmd::Eval { mode, cases, seed } => {
+            let modes: Vec<Mode> = if mode == "both" {
+                vec![Mode::C, Mode::A]
+            } else {
+                vec![mode.parse().expect("mode")]
+            };
             let p = Pipeline::load(&cfg).expect("load");
-            let m: Mode = mode.parse().expect("mode");
-            let mut sum = 0.0;
-            let mut billable_sum = 0.0;
-            let mut billable_n: f64 = 0.0;
-            let billable: Vec<_> = p.entries.iter().enumerate()
-                .filter(|(_, e)| e.valid)
-                .filter(|(_, e)| {
-                    alpha_id::corpus::primary_code(e)
-                        .and_then(|c| p.meta.get(c))
-                        .map(|mt| mt.para295 == "P").unwrap_or(false)
-                })
-                .take(cases).collect();
-            for (k, (_, e)) in billable.iter().enumerate() {
-                let code = alpha_id::corpus::primary_code(e).unwrap().to_string();
-                let noisy = inject_errors(&e.text, 0.15, seed.wrapping_add(k as u64));
-                let res = p.suggest(&noisy, m, &Filter::default(), 10);
-                let preds: Vec<String> = res.suggestions.iter().map(|s| s.icd_code.clone()).collect();
-                sum += recall_at_k(&preds, &code, 10);
-                billable_sum += recall_at_k(&preds, &code, 10);
-                billable_n += 1.0;
+            for m in modes {
+                let (r10, br10) = run_eval(&p, m, cases, seed);
+                println!("mode={:?} cases={} Recall@10={:.3} BillableRecall@10={:.3}",
+                         m, cases, r10, br10);
             }
-            let n = billable.len().max(1) as f64;
-            println!("mode={} cases={} Recall@10={:.3} BillableRecall@10={:.3}",
-                mode, billable.len(), sum / n, billable_sum / billable_n.max(1.0));
         }
     }
 }
diff --git a/tests/eval_compare_tests.rs b/tests/eval_compare_tests.rs
new file mode 100644
index 0000000..bbf212d
--- /dev/null
+++ b/tests/eval_compare_tests.rs
@@ -0,0 +1,12 @@
+use std::process::Command;
+
+#[test]
+fn eval_mode_c_runs_and_reports_billable_recall() {
+    let out = Command::new(env!("CARGO_BIN_EXE_alpha-id"))
+        .args(["eval", "--mode", "c", "--cases", "30"])
+        .arg("--config").arg("config/default.toml")
+        .output().unwrap();
+    assert!(out.status.success(), "stderr: {}", String::from_utf8_lossy(&out.stderr));
+    let s = String::from_utf8_lossy(&out.stdout);
+    assert!(s.contains("BillableRecall@10="));
+}