diff --git a/lib/autotune-prep/categorize.js b/lib/autotune-prep/categorize.js
index af2f0205..35228d88 100644
--- a/lib/autotune-prep/categorize.js
+++ b/lib/autotune-prep/categorize.js
@@ -104,6 +104,7 @@ function categorizeBGDatums(opts) {
     }
     //console.error(treatments);
     absorbing = 0;
+    uam = 0; // unannounced meal
     mealCOB = 0;
     mealCarbs = 0;
     var type="";
@@ -215,11 +216,28 @@ function categorizeBGDatums(opts) {
             //if (i == 0) { glucoseDatum.mealAbsorption = "end"; }
             CSFGlucoseData.push(glucoseDatum);
         } else {
-            // check previous "type" value, and if it was csf, set a mealAbsorption end flag
-            if ( type === "csf" ) {
-                CSFGlucoseData[CSFGlucoseData.length-1].mealAbsorption = "end";
-                console.error(CSFGlucoseData[CSFGlucoseData.length-1].mealAbsorption,"carb absorption");
+          // check previous "type" value, and if it was csf, set a mealAbsorption end flag
+          if ( type === "csf" ) {
+            CSFGlucoseData[CSFGlucoseData.length-1].mealAbsorption = "end";
+            console.error(CSFGlucoseData[CSFGlucoseData.length-1].mealAbsorption,"carb absorption");
+          }
+
+          if (iob.iob > currentBasal || uam) {
+            if (deviation > 0) {
+                uam = 1;
+            } else {
+                uam = 0;
             }
+            if ( type != "uam" ) {
+                glucoseDatum.uamAbsorption = "start";
+                console.error(glucoseDatum.uamAbsorption,"uannnounced meal absorption");
+            }
+            type="uam";
+          } else {
+            if ( type === "uam" ) {
+                console.error("end unannounced meal absorption");
+            }
+
 
             // Go through the remaining time periods and divide them into periods where scheduled basal insulin activity dominates. This would be determined by calculating the BG impact of scheduled basal insulin (for example 1U/hr * 48 mg/dL/U ISF = 48 mg/dL/hr = 5 mg/dL/5m), and comparing that to BGI from bolus and net basal insulin activity.
             // When BGI is positive (insulin activity is negative), we want to use that data to tune basals
@@ -248,9 +266,12 @@ function categorizeBGDatums(opts) {
                     ISFGlucoseData.push(glucoseDatum);
                 }
             }
+          }
         }
         // debug line to print out all the things
-        console.error(absorbing.toString(),"mealCOB:",mealCOB.toFixed(1),"mealCarbs:",mealCarbs,"basalBGI:",basalBGI.toFixed(1),"BGI:",BGI.toFixed(1),"at",BGDate,"dev:",deviation,"avgDelta:",avgDelta,type);
+        BGDateArray = BGDate.toString().split(" ");
+        BGTime = BGDateArray[4];
+        console.error(absorbing.toString(),"mealCOB:",mealCOB.toFixed(1),"mealCarbs:",mealCarbs,"basalBGI:",basalBGI.toFixed(1),"BGI:",BGI.toFixed(1),"IOB:",iob.iob.toFixed(1),"at",BGTime,"dev:",deviation,"avgDelta:",avgDelta,type);
     }
 
     return {
diff --git a/lib/determine-basal/determine-basal.js b/lib/determine-basal/determine-basal.js
index 4493e4de..ffd3de44 100644
--- a/lib/determine-basal/determine-basal.js
+++ b/lib/determine-basal/determine-basal.js
@@ -217,8 +217,8 @@ var determine_basal = function determine_basal(glucose_status, currenttemp, iob_
     // calculate current carb absorption rate, and how long to absorb all carbs
     // CI = current carb impact on BG in mg/dL/5m
     ci = round((minDelta - bgi),1);
-    if (meal_data.mealCOB * 2 > meal_data.carbs) {
-        // set ci to a minimum of 3mg/dL/5m (default) if less than half of carbs have absorbed
+    if (meal_data.mealCOB * 3 > meal_data.carbs) {
+        // set ci to a minimum of 3mg/dL/5m (default) if at least 1/3 of carbs from the last 1.5*DIA hours are still unabsorbed
         ci = Math.max(profile.min_5m_carbimpact, ci);
     }
     aci = 10;