diff --git a/src/main/javascript/update_code_display.js b/src/main/javascript/update_code_display.js
new file mode 100644
index 0000000000..2f1c168f13
--- /dev/null
+++ b/src/main/javascript/update_code_display.js
@@ -0,0 +1,270 @@
+// This is a stand alone node script to iterate through the modules
+// and update all code displays that do not match an allowed value.
+// (i.e., code displays that would not pass FHIR validation)
+// The script also attempts to standardize when the same code is used in
+// multiple modules, and to minimize the number of updates.
+// Any invalid/unknown codes will be printed to console.
+//
+// Note this does require the `sync-fetch` library to be installed first.
+// 
+// Example:
+//   npm install sync-fetch
+//   node update_code_display.js /path/to/synthea/src/main/resources/modules/
+//
+// Tested on node v20.3.1
+
+const fetch = require('sync-fetch')
+const process = require('process');
+const fs = require('fs');
+const path = require('path');
+
+const moduleDirPath = process.argv[2];
+
+let moduleDir = fs.opendirSync(moduleDirPath);
+
+const codeInventory = {};
+// codeInventory[system][code] = set("display1", "display2", ...)
+
+const allCodes = [];
+
+const codeDictionary = {};
+// codeDictionary[system][code] = "display to use"
+
+// systems to skip because tx.fhir.org doesn't know about them
+const SYSTEMS_TO_SKIP = ['NUBC', 'DICOM-DCM', 'DICOM-SOP'];
+
+// codes used in Synthea as placeholders that we know aren't real
+const PLACEHOLDER_CODES = ['999999',
+  "99999-0", "99999-1", "99999-2", "99999-3", "99999-4",
+  "99999-5", "99999-6", "99999-7", "99999-8", "99999-9",
+  "99999-10", "99999-11",
+  'X9999-0', 'X9999-1', 'X9999-2'];
+
+const CODE_SYSTEM_URIS = {
+ 'SNOMED-CT': 'http://snomed.info/sct',
+ 'LOINC': 'http://loinc.org',
+ 'RxNorm': 'http://www.nlm.nih.gov/research/umls/rxnorm',
+ 'CVX': 'http://hl7.org/fhir/sid/cvx'
+};
+
+if (fs.existsSync('./code_dictionary.json')) {
+  const rawJSON = fs.readFileSync('./code_dictionary.json');
+  const loadedDictionary = JSON.parse(rawJSON);
+  Object.assign(codeDictionary, loadedDictionary);
+  console.log("Using previously saved ./code_dictionary.json")
+} else {
+  processFiles(moduleDir, moduleDirPath, inventoryAllCodes);
+  // the Sets used in the inventory don't stringify properly,
+  // so this replacer function turns them into arrays
+  // https://stackoverflow.com/a/46491780
+  const jsonifySets = (_key, value) => (value instanceof Set ? [...value] : value);
+  fs.writeFileSync('./code_inventory.json', JSON.stringify(codeInventory, jsonifySets, 2));
+  console.log("Saved ./code_inventory.json")
+
+  buildDictionary();
+  fs.writeFileSync('./code_dictionary.json', JSON.stringify(codeDictionary, null, 2));
+  console.log("Saved ./code_dictionary.json")
+
+  // re-open the module dir to re-iterate through it
+  moduleDir = fs.opendirSync(moduleDirPath);
+}
+
+processFiles(moduleDir, moduleDirPath, checkAndUpdateAllCodes);
+
+/**
+ * Process all the module files in the given directory
+ * by applying the given function to each path.
+ */
+function processFiles(dirEntry, parentPath, fileFunction) {
+  let fileInFolder = dirEntry.readSync();
+  while (fileInFolder != null) {
+    if(fileInFolder.isDirectory()) {
+      const newPath = path.join(parentPath, fileInFolder.name);
+      const subDir = fs.opendirSync(newPath);
+      processFiles(subDir, newPath, fileFunction);
+    } else if (fileInFolder.isFile() && fileInFolder.name.endsWith('.json')) {
+      const moduleJSONPath = path.join(parentPath, fileInFolder.name);
+      fileFunction(moduleJSONPath);
+    }
+    fileInFolder = dirEntry.readSync();
+  }
+}
+
+function inventoryAllCodes(moduleJSONPath) {
+  console.log(`Inventorying ${moduleJSONPath}`);
+  const rawJSON = fs.readFileSync(moduleJSONPath);
+  let module = JSON.parse(rawJSON);
+  
+  walkObject(module, inventoryCode);
+}
+
+function checkAndUpdateAllCodes(moduleJSONPath) {
+  console.log(`Checking and updating ${moduleJSONPath}`);
+  const rawJSON = fs.readFileSync(moduleJSONPath);
+  let module = JSON.parse(rawJSON);
+  
+  walkObject(module, checkAndUpdateCode);
+
+  const updatedModuleJSON = JSON.stringify(module, null, 2);
+  fs.writeFileSync(moduleJSONPath, updatedModuleJSON);
+}
+
+/**
+ * Recursively iterate through the given object and
+ * apply the given function to any "code" objects.
+ * A "code" object is one that has fields "system", "code", and "display".
+ */
+function walkObject(object, codeFunction) {
+  if (Array.isArray(object)) {
+    object.forEach(o => walkObject(o, codeFunction));
+  } else if (typeof object === 'object' && object !== null) {
+    if (object.system && object.code && object.display) {
+      if (SYSTEMS_TO_SKIP.includes(object.system) || PLACEHOLDER_CODES.includes(object.code.toString())) {
+        return;
+      }
+      codeFunction(object);
+    } else {
+      for (const [key, value] of Object.entries(object)) {
+        walkObject(value, codeFunction);
+      }
+    }
+  }
+  // else, it's a null or primitive, nothing to do
+}
+
+/**
+ * Add the given code to the inventory.
+ */
+function inventoryCode(codeObj) {
+  let { system, code, display } = codeObj;
+  code = code.toString();
+
+  if (!codeInventory[system]) {
+    codeInventory[system] = {};
+  }
+  if (!codeInventory[system][code]) {
+    codeInventory[system][code] = new Set();
+    allCodes.push(codeObj);
+  }
+
+  codeInventory[system][code].add(display);
+}
+
+function buildDictionary() {
+  for (const codeObj of allCodes) {
+    let { system, code, display } = codeObj;
+    code = code.toString();
+    if (!codeDictionary[system]) {
+      codeDictionary[system] = {};
+    }
+    let systemUri = CODE_SYSTEM_URIS[system];
+    if (!systemUri) {
+      systemUri = system;
+      console.log(`Unexpected code system ${system} may not be supported by tx.fhir.org`);
+    }
+    // http://hl7.org/fhir/R4/terminology-service.html#validation
+    const requestUrl = `http://tx.fhir.org/r4/CodeSystem/$validate-code?system=${systemUri}&code=${code}&display=${display}`
+
+    const res = fetch(requestUrl, { headers: { "Accept": "application/fhir+json" } }).json();
+
+    const displayParam = res.parameter.find(p => p.name === 'display');
+    const success = res.parameter.find(p => p.name === 'result').valueBoolean;
+
+    if (displayParam) {
+      // the "display" param of the response contains a preferred code.
+      // NOTE: in the case of SNOMED, the returned code is preferred but
+      // not necessarily the "fully specified name".
+      // eg, it may return "Aspirin" instead of "Aspirin (substance)"
+      const aPreferredDisplay = displayParam.valueString;
+
+      // success indicates whether the provided code was allowed
+      const currentDisplay = success ? display : null;
+
+      const bestDisplay = selectBestCode(system, codeInventory[system][code], aPreferredDisplay, currentDisplay);
+      codeDictionary[system][code] = bestDisplay;
+    } else {
+      handleErrorOrExit(requestUrl, res);
+    }
+  }
+}
+
+function selectBestCode(system, inventory, aPreferredDisplay, currentDisplay) {
+  if (system === 'SNOMED-CT' && !aPreferredDisplay.endsWith(")")) {
+    // if the preferred code that the server returned doesn't have the semantic tag
+    // then do some special logic
+    for (const option of inventory) {
+      // if we already use the preferred display with a snomed semantic tag, use that.
+      // some codes aren't regex safe
+      const regexSafeDisplay = display.replaceAll('+', '\\+').replaceAll('(', '\\(').replaceAll(')', '\\)');
+      if (option.match(new RegExp(`^${regexSafeDisplay} \\([a-z\\+/ ]+\\)$`, 'i'))) {
+        return option;
+      }
+    }
+  }
+
+  if (inventory.has(aPreferredDisplay)) {
+    // we use the preferred display somewhere already, stick to it
+    return aPreferredDisplay;
+  } else if (currentDisplay) {
+    // standardize to this current display to reduce changes
+    return currentDisplay;
+  } else {
+    return aPreferredDisplay;
+  }
+}
+
+/**
+ * Check whether the display on the given code is appropriate,
+ * and if not, update it.
+ */
+function checkAndUpdateCode(codeObj) {
+  let { system, code, display } = codeObj;
+  code = code.toString();
+  if (!codeDictionary[system][code]) {
+    // something went wrong in validating the code earlier,
+    // the log will show what it was
+    return;
+  }
+
+  const bestDisplay = codeDictionary[system][code];
+
+  if (system === 'SNOMED-CT') {
+    const regexSafeDisplay = display.replaceAll('+', '\\+').replaceAll('(', '\\(').replaceAll(')', '\\)');
+    if (bestDisplay.match(new RegExp(`^${regexSafeDisplay} \\([a-z\\+/ ]+\\)$`, 'i'))) {
+      // don't update just to add the snomed semantic tag 
+      return;
+    }
+  }
+
+  // capitalization doesn't appear to matter, so only update a code
+  // if it differs in more than just caps
+  if (bestDisplay.toLowerCase() != display.toLowerCase()) {
+    console.log(`Updating "${display}" -> "${bestDisplay}"`)
+    codeObj.display = bestDisplay;
+  }
+}
+
+/**
+ * Handle errors from the terminology service.
+ * "Unknown code" errors are expected so just print those out to the log.
+ * Anything else, print the request and response then exit.
+ */
+function handleErrorOrExit(requestUrl, res) {
+  const messageParam = res.parameter.find(p => p.name === 'message');
+  if (messageParam) {
+    const message = messageParam.valueString;
+
+    if (message.startsWith("Unable to find code ") 
+      || message.startsWith("Unknown Code '")) {
+      console.log(message);
+      return;
+    }
+  }
+  // something else went wrong. print message and stop
+  console.log("Error occurred.")
+  console.log("Request URL:")
+  console.log(requestUrl);
+  console.log("\nResponse:")
+  console.log(JSON.stringify(res, null, 2));
+  process.exit(1);
+}
diff --git a/src/main/resources/modules/cerebral_palsy.json b/src/main/resources/modules/cerebral_palsy.json
index 03d2aefc0a..50a336b705 100644
--- a/src/main/resources/modules/cerebral_palsy.json
+++ b/src/main/resources/modules/cerebral_palsy.json
@@ -555,7 +555,7 @@
       "codes": [
         {
           "system": "SNOMED-CT",
-          "code": 7227006,
+          "code": 47227006,
           "display": "Excision of submandibular gland (procedure)"
         }
       ],
@@ -929,7 +929,7 @@
       "codes": [
         {
           "system": "RxNorm",
-          "code": 143975,
+          "code": 1437975,
           "display": "glycopyrrolate 1.5 MG Oral Tablet [Glycate]"
         }
       ],
diff --git a/src/main/resources/modules/congestive_heart_failure.json b/src/main/resources/modules/congestive_heart_failure.json
index 3b72839973..ba8eef0308 100644
--- a/src/main/resources/modules/congestive_heart_failure.json
+++ b/src/main/resources/modules/congestive_heart_failure.json
@@ -1178,7 +1178,7 @@
           "display": "Ibuprofen 100 MG Oral Tablet"
         },
         {
-          "system": "SNOMED-CT",
+          "system": "RxNorm",
           "code": 310965,
           "display": "Ibuprofen 200 MG Oral Tablet"
         }
diff --git a/src/main/resources/modules/heart/avrr/preoperative.json b/src/main/resources/modules/heart/avrr/preoperative.json
index aad84f2e5e..2e387fd975 100644
--- a/src/main/resources/modules/heart/avrr/preoperative.json
+++ b/src/main/resources/modules/heart/avrr/preoperative.json
@@ -258,8 +258,8 @@
       "codes": [
         {
           "system": "SNOMED-CT",
-          "code": 3336700,
-          "display": "Coronary angiography (procedure)"
+          "code": 33367005,
+          "display": "Angiography of coronary artery (procedure)"
         }
       ],
       "unit": "minutes",
diff --git a/src/main/resources/modules/heart/avrr/savrr_postop.json b/src/main/resources/modules/heart/avrr/savrr_postop.json
index d5f9056ee6..f62f4beb19 100644
--- a/src/main/resources/modules/heart/avrr/savrr_postop.json
+++ b/src/main/resources/modules/heart/avrr/savrr_postop.json
@@ -458,7 +458,7 @@
         },
         {
           "system": "SNOMED-CT",
-          "code": 22972009,
+          "code": 422972009,
           "display": "Advance diet as tolerated (regime/therapy)"
         },
         {
diff --git a/src/main/resources/modules/heart/tavr/alt_access.json b/src/main/resources/modules/heart/tavr/alt_access.json
index 0baf3d004f..ac08d3f77b 100644
--- a/src/main/resources/modules/heart/tavr/alt_access.json
+++ b/src/main/resources/modules/heart/tavr/alt_access.json
@@ -128,7 +128,7 @@
       "value_code": {
         "system": "SNOMED-CT",
         "code": 260582008,
-        "display": "SNOMED Code"
+        "display": "Via carotid artery"
       }
     },
     "Other": {
diff --git a/src/main/resources/modules/heart/tavr/postop.json b/src/main/resources/modules/heart/tavr/postop.json
index beac3a29b4..b0b16a93a4 100644
--- a/src/main/resources/modules/heart/tavr/postop.json
+++ b/src/main/resources/modules/heart/tavr/postop.json
@@ -486,7 +486,7 @@
         },
         {
           "system": "SNOMED-CT",
-          "code": 22972009,
+          "code": 422972009,
           "display": "Advance diet as tolerated (regime/therapy)"
         },
         {
diff --git a/src/main/resources/modules/hiv/hiv_screening.json b/src/main/resources/modules/hiv/hiv_screening.json
index d421be66cd..81dcabd80b 100644
--- a/src/main/resources/modules/hiv/hiv_screening.json
+++ b/src/main/resources/modules/hiv/hiv_screening.json
@@ -16,7 +16,7 @@
       "codes": [
         {
           "system": "SNOMED-CT",
-          "code": 71121004,
+          "code": 171121004,
           "display": "Human immunodeficiency virus screening (procedure)"
         }
       ],
diff --git a/src/main/resources/modules/spina_bifida.json b/src/main/resources/modules/spina_bifida.json
index 38436d5fb2..160136b40f 100644
--- a/src/main/resources/modules/spina_bifida.json
+++ b/src/main/resources/modules/spina_bifida.json
@@ -219,7 +219,7 @@
       "codes": [
         {
           "system": "SNOMED-CT",
-          "code": 36321500,
+          "code": 363215001,
           "display": "Musculoskeletal system physical examination (procedure)"
         }
       ],
diff --git a/src/main/resources/modules/uti/gu_pregnancy_check.json b/src/main/resources/modules/uti/gu_pregnancy_check.json
index 4cab684af3..61d7d8ecc7 100644
--- a/src/main/resources/modules/uti/gu_pregnancy_check.json
+++ b/src/main/resources/modules/uti/gu_pregnancy_check.json
@@ -122,9 +122,9 @@
       "direct_transition": "Terminal",
       "name": "Negative Result",
       "value_code": {
-        "system": "LOINC",
+        "system": "SNOMED-CT",
         "code": 260385009,
-        "display": "Negative"
+        "display": "Negative (qualifier value)"
       }
     },
     "Positive Result": {
@@ -141,9 +141,9 @@
       ],
       "name": "Positive Result",
       "value_code": {
-        "system": "LOINC",
+        "system": "SNOMED-CT",
         "code": 10828004,
-        "display": "Positive"
+        "display": "Positive (qualifier value)"
       },
       "direct_transition": "Terminal"
     }