diff --git a/common-docs/teachertool/catalog-shared.json b/common-docs/teachertool/catalog-shared.json
index 883162e77ca0..af52b385028d 100644
--- a/common-docs/teachertool/catalog-shared.json
+++ b/common-docs/teachertool/catalog-shared.json
@@ -6,6 +6,7 @@
             "template": "${Block} used ${count} times",
             "description": "This block was used the specified number of times in your project.",
             "docPath": "/teachertool",
+            "tags": ["General"],
             "params": [
                 {
                     "name": "block",
@@ -27,6 +28,7 @@
             "description": "The project contains at least the specified number of comments.",
             "docPath": "/teachertool",
             "maxCount": 1,
+            "tags": ["General"],
             "params": [
                 {
                     "name": "count",
@@ -43,6 +45,7 @@
             "docPath": "/teachertool",
             "description": "The program uses at least this many loops of any kind (for, repeat, while, or for-of).",
             "maxCount": 1,
+            "tags": ["Code Elements"],
             "params": [
                 {
                     "name": "count",
@@ -59,6 +62,7 @@
             "docPath": "/teachertool",
             "description": "At least this many user-defined functions are created and called.",
             "maxCount": 1,
+            "tags": ["Code Elements"],
             "params": [
                 {
                     "name": "count",
@@ -75,6 +79,7 @@
             "docPath": "/teachertool",
             "description": "The program creates and uses at least this many user-defined variables.",
             "maxCount": 1,
+            "tags": ["Code Elements"],
             "params": [
                 {
                     "name": "count",
diff --git a/common-docs/teachertool/test/catalog-shared.json b/common-docs/teachertool/test/catalog-shared.json
index 73e98c28ce44..bd4db6dc9042 100644
--- a/common-docs/teachertool/test/catalog-shared.json
+++ b/common-docs/teachertool/test/catalog-shared.json
@@ -7,6 +7,7 @@
             "description": "Experimental: AI outputs may not be accurate. Use with caution and always review responses.",
             "docPath": "/teachertool",
             "maxCount": 10,
+            "tags": ["General"],
             "params": [
                 {
                     "name": "question",
diff --git a/react-common/components/controls/Accordion/Accordion.tsx b/react-common/components/controls/Accordion/Accordion.tsx
index 15ae70e29d33..a6c1e092545a 100644
--- a/react-common/components/controls/Accordion/Accordion.tsx
+++ b/react-common/components/controls/Accordion/Accordion.tsx
@@ -1,15 +1,19 @@
 import * as React from "react";
 import { ContainerProps, classList, fireClickOnEnter } from "../../util";
 import { useId } from "../../../hooks/useId";
-import { AccordionProvider, clearExpanded, setExpanded, useAccordionDispatch, useAccordionState } from "./context";
+import { AccordionProvider, removeExpanded, setExpanded, useAccordionDispatch, useAccordionState } from "./context";
 
 export interface AccordionProps extends ContainerProps {
+    multiExpand?: boolean;
+    defaultExpandedIds?: string[];
     children?: React.ReactElement<AccordionItemProps>[] | React.ReactElement<AccordionItemProps>;
 }
 
 export interface AccordionItemProps extends ContainerProps {
     children?: [React.ReactElement<AccordionHeaderProps>, React.ReactElement<AccordionPanelProps>];
     noChevron?: boolean;
+    itemId?: string;
+    onExpandToggled?: (expanded: boolean) => void;
 }
 
 export interface AccordionHeaderProps extends ContainerProps {
@@ -27,10 +31,12 @@ export const Accordion = (props: AccordionProps) => {
         ariaHidden,
         ariaDescribedBy,
         role,
+        multiExpand,
+        defaultExpandedIds
     } = props;
 
     return (
-        <AccordionProvider>
+        <AccordionProvider multiExpand={multiExpand} defaultExpandedIds={defaultExpandedIds}>
             <div
                 className={classList("common-accordion", className)}
                 id={id}
@@ -54,23 +60,26 @@ export const AccordionItem = (props: AccordionItemProps) => {
         ariaHidden,
         ariaDescribedBy,
         role,
-        noChevron
+        noChevron,
+        itemId,
+        onExpandToggled,
     } = props;
 
     const { expanded } = useAccordionState();
     const dispatch = useAccordionDispatch();
 
-    const panelId = useId();
+    const panelId = itemId ?? useId();
     const mappedChildren = React.Children.toArray(children);
-    const isExpanded = expanded === panelId;
+    const isExpanded = expanded.indexOf(panelId) !== -1;
 
     const onHeaderClick = React.useCallback(() => {
         if (isExpanded) {
-            dispatch(clearExpanded());
+            dispatch(removeExpanded(panelId));
         }
         else {
             dispatch(setExpanded(panelId));
         }
+        onExpandToggled?.(!isExpanded);
     }, [isExpanded]);
 
     return (
@@ -150,4 +159,4 @@ export const AccordionPanel = (props: AccordionPanelProps) => {
             {children}
         </div>
     );
-}
\ No newline at end of file
+}
diff --git a/react-common/components/controls/Accordion/context.tsx b/react-common/components/controls/Accordion/context.tsx
index 8bde33951a30..c2b591c6d70c 100644
--- a/react-common/components/controls/Accordion/context.tsx
+++ b/react-common/components/controls/Accordion/context.tsx
@@ -1,17 +1,22 @@
 import * as React from "react";
 
 interface AccordionState {
-    expanded?: string;
+    multiExpand?: boolean;
+    expanded: string[];
 }
 
 const AccordionStateContext = React.createContext<AccordionState>(null);
 const AccordionDispatchContext = React.createContext<(action: Action) => void>(null);
 
-export const AccordionProvider = ({ children }: React.PropsWithChildren<{}>) => {
-    const [state, dispatch] = React.useReducer(
-        accordionReducer,
-        {}
-    );
+export const AccordionProvider = ({
+    multiExpand,
+    defaultExpandedIds,
+    children,
+}: React.PropsWithChildren<{ multiExpand?: boolean; defaultExpandedIds?: string[] }>) => {
+    const [state, dispatch] = React.useReducer(accordionReducer, {
+        expanded: defaultExpandedIds ?? [],
+        multiExpand,
+    });
 
     return (
         <AccordionStateContext.Provider value={state}>
@@ -27,11 +32,12 @@ type SetExpanded = {
     id: string;
 };
 
-type ClearExpanded = {
-    type: "CLEAR_EXPANDED";
+type RemoveExpanded = {
+    type: "REMOVE_EXPANDED";
+    id: string;
 };
 
-type Action = SetExpanded | ClearExpanded;
+type Action = SetExpanded | RemoveExpanded;
 
 export const setExpanded = (id: string): SetExpanded => (
     {
@@ -40,14 +46,15 @@ export const setExpanded = (id: string): SetExpanded => (
     }
 );
 
-export const clearExpanded = (): ClearExpanded => (
+export const removeExpanded = (id: string): RemoveExpanded => (
     {
-        type: "CLEAR_EXPANDED"
+        type: "REMOVE_EXPANDED",
+        id
     }
 );
 
 export function useAccordionState() {
-    return React.useContext(AccordionStateContext)
+    return React.useContext(AccordionStateContext);
 }
 
 export function useAccordionDispatch() {
@@ -59,12 +66,12 @@ function accordionReducer(state: AccordionState, action: Action): AccordionState
         case "SET_EXPANDED":
             return {
                 ...state,
-                expanded: action.id
+                expanded: state.multiExpand ? [...state.expanded, action.id] : [action.id],
             };
-        case "CLEAR_EXPANDED":
+        case "REMOVE_EXPANDED":
             return {
                 ...state,
-                expanded: undefined
+                expanded: state.expanded.filter((id) => id !== action.id),
             };
     }
-}
\ No newline at end of file
+}
diff --git a/teachertool/src/components/CatalogOverlay.tsx b/teachertool/src/components/CatalogOverlay.tsx
index f01a244aaf56..1c0f64fd0b62 100644
--- a/teachertool/src/components/CatalogOverlay.tsx
+++ b/teachertool/src/components/CatalogOverlay.tsx
@@ -6,11 +6,15 @@ import { getCatalogCriteria } from "../state/helpers";
 import { ReadOnlyCriteriaDisplay } from "./ReadonlyCriteriaDisplay";
 import { Strings } from "../constants";
 import { Button } from "react-common/components/controls/Button";
-import { getReadableCriteriaTemplate, makeToast } from "../utils";
+import { Accordion } from "react-common/components/controls/Accordion";
+import { getReadableCriteriaTemplate } from "../utils";
 import { setCatalogOpen } from "../transforms/setCatalogOpen";
 import { classList } from "react-common/components/util";
 import { announceToScreenReader } from "../transforms/announceToScreenReader";
 import { FocusTrap } from "react-common/components/controls/FocusTrap";
+import { logError } from "../services/loggingService";
+import { ErrorCode } from "../types/errorCode";
+import { addExpandedCatalogTag, getExpandedCatalogTags, removeExpandedCatalogTag } from "../services/storageService";
 import css from "./styling/CatalogOverlay.module.scss";
 
 interface CatalogHeaderProps {
@@ -67,16 +71,59 @@ const CatalogItemLabel: React.FC<CatalogItemLabelProps> = ({ catalogCriteria, is
     );
 };
 
+interface CatalogItemProps {
+    catalogCriteria: CatalogCriteria;
+    recentlyAddedIds: pxsim.Map<NodeJS.Timeout>;
+    onItemClicked: (c: CatalogCriteria) => void;
+}
+const CatalogItem: React.FC<CatalogItemProps> = ({ catalogCriteria, recentlyAddedIds, onItemClicked }) => {
+    const { state: teacherTool } = useContext(AppStateContext);
+
+    const existingInstanceCount = teacherTool.checklist.criteria.filter(
+        i => i.catalogCriteriaId === catalogCriteria.id
+    ).length;
+    const isMaxed = catalogCriteria.maxCount !== undefined && existingInstanceCount >= catalogCriteria.maxCount;
+    return catalogCriteria.template ? (
+        <Button
+            title={getReadableCriteriaTemplate(catalogCriteria)}
+            key={catalogCriteria.id}
+            className={css["catalog-item"]}
+            label={
+                <CatalogItemLabel
+                    catalogCriteria={catalogCriteria}
+                    isMaxed={isMaxed}
+                    recentlyAdded={recentlyAddedIds[catalogCriteria.id] !== undefined}
+                />
+            }
+            onClick={() => onItemClicked(catalogCriteria)}
+            disabled={isMaxed}
+        />
+    ) : null;
+};
+
 const CatalogList: React.FC = () => {
     const { state: teacherTool } = useContext(AppStateContext);
 
     const recentlyAddedWindowMs = 500;
     const [recentlyAddedIds, setRecentlyAddedIds] = useState<pxsim.Map<NodeJS.Timeout>>({});
 
-    const criteria = useMemo<CatalogCriteria[]>(
-        () => getCatalogCriteria(teacherTool),
-        [teacherTool.catalog, teacherTool.checklist]
-    );
+    // For now, we only look at the first tag of each criteria.
+    const criteriaGroupedByTag = useMemo<pxt.Map<CatalogCriteria[]>>(() => {
+        const grouped: pxt.Map<CatalogCriteria[]> = {};
+        getCatalogCriteria(teacherTool)?.forEach(c => {
+            if (!c.tags || c.tags.length === 0) {
+                logError(ErrorCode.missingTag, { message: "Catalog criteria missing tag", criteria: c });
+                return;
+            }
+
+            const tag = c.tags[0];
+            if (!grouped[tag]) {
+                grouped[tag] = [];
+            }
+            grouped[tag].push(c);
+        });
+        return grouped;
+    }, [teacherTool.catalog]);
 
     function updateRecentlyAddedValue(id: string, value: NodeJS.Timeout | undefined) {
         setRecentlyAddedIds(prevState => {
@@ -106,34 +153,55 @@ const CatalogList: React.FC = () => {
         announceToScreenReader(lf("Added '{0}' to checklist.", getReadableCriteriaTemplate(c)));
     }
 
+    function getItemIdForTag(tag: string) {
+        return `accordion-item-${tag}`;
+    }
+
+    function onTagExpandToggled(tag: string, expanded: boolean) {
+        if (expanded) {
+            addExpandedCatalogTag(tag);
+        } else {
+            removeExpandedCatalogTag(tag);
+        }
+    }
+
+    const tags = Object.keys(criteriaGroupedByTag);
+    if (tags.length === 0) {
+        logError(ErrorCode.noCatalogCriteria);
+        return null;
+    }
+
+    let expandedTags = getExpandedCatalogTags();
+    if (!expandedTags) {
+        // If we haven't saved an expanded set, default expand the first one.
+        addExpandedCatalogTag(tags[0]);
+        expandedTags = [tags[0]];
+    }
+
+    const expandedIds = expandedTags.map(t => getItemIdForTag(t));
     return (
-        <div className={css["catalog-list"]}>
-            {criteria.map(c => {
-                const existingInstanceCount = teacherTool.checklist.criteria.filter(
-                    i => i.catalogCriteriaId === c.id
-                ).length;
-                const isMaxed = c.maxCount !== undefined && existingInstanceCount >= c.maxCount;
+        <Accordion className={css["catalog-list"]} multiExpand={true} defaultExpandedIds={expandedIds}>
+            {tags.map(tag => {
                 return (
-                    c.template && (
-                        <Button
-                            id={`criteria_${c.id}`}
-                            title={getReadableCriteriaTemplate(c)}
-                            key={c.id}
-                            className={css["catalog-item"]}
-                            label={
-                                <CatalogItemLabel
+                    <Accordion.Item
+                        itemId={getItemIdForTag(tag)}
+                        onExpandToggled={expanded => onTagExpandToggled(tag, expanded)}
+                        key={getItemIdForTag(tag)}
+                    >
+                        <Accordion.Header>{tag}</Accordion.Header>
+                        <Accordion.Panel>
+                            {criteriaGroupedByTag[tag].map(c => (
+                                <CatalogItem
                                     catalogCriteria={c}
-                                    isMaxed={isMaxed}
-                                    recentlyAdded={recentlyAddedIds[c.id] !== undefined}
+                                    recentlyAddedIds={recentlyAddedIds}
+                                    onItemClicked={onItemClicked}
                                 />
-                            }
-                            onClick={() => onItemClicked(c)}
-                            disabled={isMaxed}
-                        />
-                    )
+                            ))}
+                        </Accordion.Panel>
+                    </Accordion.Item>
                 );
             })}
-        </div>
+        </Accordion>
     );
 };
 
diff --git a/teachertool/src/components/styling/CatalogOverlay.module.scss b/teachertool/src/components/styling/CatalogOverlay.module.scss
index 94c1db07038b..66c5b8ff6acf 100644
--- a/teachertool/src/components/styling/CatalogOverlay.module.scss
+++ b/teachertool/src/components/styling/CatalogOverlay.module.scss
@@ -14,8 +14,8 @@
     align-items: center;
 
     .catalog-content-container {
-        max-width: 95%;
-        max-height: 95%;
+        width: 95%;
+        height: 95%;
         background-color: var(--pxt-page-background);
         border-radius: .285rem; // Match modal
         display: flex;
@@ -57,6 +57,19 @@
             display: flex;
             flex-direction: column;
             width: 100%;
+            height: 100%;
+
+            div[class*="common-accordion-chevron"] {
+                width: 3rem; // Match action-indicators
+            }
+
+            button[class*="common-accordion-header-outer"] {
+                background-color: var(--pxt-content-foreground);
+                color: var(--pxt-content-background);
+                border-bottom: 1px solid var(--pxt-content-accent);
+                font-size: 1.2rem;
+                padding: 0.5rem 0.95rem;
+            }
 
             .catalog-item {
                 width: 100%;
@@ -77,7 +90,7 @@
                     .action-indicators {
                         position: relative;
                         padding: 0 1rem 0 0;
-                        width: 3rem;
+                        width: 3rem; // Match common-accordion-chevron
                         display: flex;
                         align-items: center;
                         justify-content: center;
diff --git a/teachertool/src/components/styling/ReadonlyCriteriaDisplay.module.scss b/teachertool/src/components/styling/ReadonlyCriteriaDisplay.module.scss
index 6cef3907b25c..766b19832629 100644
--- a/teachertool/src/components/styling/ReadonlyCriteriaDisplay.module.scss
+++ b/teachertool/src/components/styling/ReadonlyCriteriaDisplay.module.scss
@@ -2,6 +2,8 @@
     display: flex;
     flex-direction: column;
     align-items: flex-start;
+    text-wrap: wrap;
+    text-align: start;
 
     .criteria-template {
         margin-bottom: 0.4rem;
diff --git a/teachertool/src/constants.ts b/teachertool/src/constants.ts
index ea7a9f264721..cc502c2a006f 100644
--- a/teachertool/src/constants.ts
+++ b/teachertool/src/constants.ts
@@ -33,6 +33,7 @@ export namespace Strings {
     export const Checklist = lf("Checklist");
     export const Home = lf("Home");
     export const CreateEmptyChecklist = lf("Create Empty Checklist");
+    export const Other = lf("Other");
 }
 
 export namespace Ticks {
diff --git a/teachertool/src/services/storageService.ts b/teachertool/src/services/storageService.ts
index 34f729e20937..4cbfce534a80 100644
--- a/teachertool/src/services/storageService.ts
+++ b/teachertool/src/services/storageService.ts
@@ -11,6 +11,7 @@ const KEY_PREFIX = "teachertool";
 const AUTORUN_KEY = [KEY_PREFIX, "autorun"].join("/");
 const LAST_ACTIVE_CHECKLIST_KEY = [KEY_PREFIX, "lastActiveChecklist"].join("/");
 const SPLIT_POSITION_KEY = [KEY_PREFIX, "splitPosition"].join("/");
+const EXPANDED_CATALOG_TAGS_KEY = [KEY_PREFIX, "expandedCatalogTags"].join("/");
 
 function getValue(key: string, defaultValue?: string): string | undefined {
     return localStorage.getItem(key) || defaultValue;
@@ -192,3 +193,45 @@ export async function deleteChecklistAsync(name: string) {
         setLastActiveChecklistName("");
     }
 }
+
+// Returns undefined if it has not been set or if there was an issue.
+// Empty list means it was explicitly set to empty.
+export function getExpandedCatalogTags(): string[] | undefined {
+    try {
+        const tags = getValue(EXPANDED_CATALOG_TAGS_KEY);
+        return tags ? JSON.parse(tags) : undefined;
+    } catch (e) {
+        logError(ErrorCode.localStorageReadError, e);
+        return undefined;
+    }
+}
+
+export function setExpandedCatalogTags(tags: string[]) {
+    try {
+        setValue(EXPANDED_CATALOG_TAGS_KEY, JSON.stringify(tags));
+    } catch (e) {
+        logError(ErrorCode.localStorageWriteError, e);
+    }
+}
+
+export function addExpandedCatalogTag(tag: string) {
+    let expandedTags = getExpandedCatalogTags();
+    if (!expandedTags) {
+        expandedTags = [];
+    }
+    expandedTags.push(tag);
+    setExpandedCatalogTags(expandedTags);
+}
+
+export function removeExpandedCatalogTag(tag: string) {
+    let expandedTags = getExpandedCatalogTags();
+    if (!expandedTags) {
+        setExpandedCatalogTags([]);
+    } else {
+        const index = expandedTags.indexOf(tag);
+        if (index !== -1) {
+            expandedTags.splice(index, 1);
+            setExpandedCatalogTags(expandedTags);
+        }
+    }
+}
diff --git a/teachertool/src/transforms/loadCatalogAsync.ts b/teachertool/src/transforms/loadCatalogAsync.ts
index 876704bde6f1..607f73e72452 100644
--- a/teachertool/src/transforms/loadCatalogAsync.ts
+++ b/teachertool/src/transforms/loadCatalogAsync.ts
@@ -1,3 +1,4 @@
+import { Strings } from "../constants";
 import { loadTestableCollectionFromDocsAsync } from "../services/backendRequests";
 import { stateAndDispatch } from "../state";
 import * as Actions from "../state/actions";
@@ -12,11 +13,16 @@ export async function loadCatalogAsync() {
     const { dispatch } = stateAndDispatch();
     const fullCatalog = await loadTestableCollectionFromDocsAsync<CatalogCriteria>(prodFiles, "criteria");
 
-    // Convert parameter names to lower-case for case-insensitive matching
     fullCatalog.forEach(c => {
+        // Convert parameter names to lower-case for case-insensitive matching
         c.params?.forEach(p => {
             p.name = p.name.toLocaleLowerCase();
         });
+
+        // Add default tag if none are present
+        if (!c.tags || c.tags.length === 0) {
+            c.tags = [Strings.Other];
+        }
     });
 
     dispatch(Actions.setCatalog(fullCatalog));
diff --git a/teachertool/src/types/criteria.ts b/teachertool/src/types/criteria.ts
index 97f9ac6e68cb..4b91bd3737d2 100644
--- a/teachertool/src/types/criteria.ts
+++ b/teachertool/src/types/criteria.ts
@@ -8,6 +8,7 @@ export interface CatalogCriteria {
     params: CriteriaParameter[] | undefined; // Any parameters that affect the criteria
     hideInCatalog?: boolean; // Whether the criteria should be hidden in the user-facing catalog
     maxCount?: number; // The maximum number of instances allowed for this criteria within a single checklist. Unlimited if undefined.
+    tags?: string[]; // Tags to help categorize the criteria
 }
 
 // An instance of a criteria in a checklist.
diff --git a/teachertool/src/types/errorCode.ts b/teachertool/src/types/errorCode.ts
index f122a6b22bcc..bd689967f331 100644
--- a/teachertool/src/types/errorCode.ts
+++ b/teachertool/src/types/errorCode.ts
@@ -26,4 +26,6 @@ export enum ErrorCode {
     unrecognizedSystemParameter = "unrecognizedSystemParameter",
     invalidValidatorPlan = "invalidValidatorPlan",
     askCopilotQuestion = "askCopilotQuestion",
+    missingTag = "missingTag",
+    noCatalogCriteria = "noCatalogCriteria"
 }