diff --git a/packages/money-account-api-data-service/CHANGELOG.md b/packages/money-account-api-data-service/CHANGELOG.md
index eb37fcf0aa4..7d5bf714e09 100644
--- a/packages/money-account-api-data-service/CHANGELOG.md
+++ b/packages/money-account-api-data-service/CHANGELOG.md
@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Response validation now tolerates unknown fields returned by the Money Account API instead of throwing `MoneyAccountApiResponseValidationError`, so additive backend changes no longer break clients ([#10538](https://github.com/MetaMask/core/pull/10538))
 - Bump `@tanstack/query-core` from `^5.89.0` to `^5.103.2` ([#10511](https://github.com/MetaMask/core/pull/10511))
 
 ## [2.0.0]
diff --git a/packages/money-account-api-data-service/src/money-account-api-data-service.test.ts b/packages/money-account-api-data-service/src/money-account-api-data-service.test.ts
index b2b44981d19..69e5dc9fff7 100644
--- a/packages/money-account-api-data-service/src/money-account-api-data-service.test.ts
+++ b/packages/money-account-api-data-service/src/money-account-api-data-service.test.ts
@@ -1298,6 +1298,124 @@ describe('MoneyAccountApiDataService', () => {
     });
   });
 
+  describe('additive API fields', () => {
+    it('accepts unknown fields on positions responses without stripping them', async () => {
+      const { service } = createService(Env.DEV);
+      const responseWithExtras = {
+        ...MOCK_POSITION_RESPONSE,
+        future_top_level: 'ok',
+        balance: {
+          ...MOCK_POSITION_RESPONSE.balance,
+          future_balance_field: 1,
+          by_asset: [
+            {
+              ...MOCK_POSITION_RESPONSE.balance.by_asset[0],
+              future_asset_field: true,
+            },
+          ],
+        },
+        positions: [
+          {
+            ...MOCK_POSITION_RESPONSE.positions[0],
+            future_position_field: 'premium',
+          },
+        ],
+      };
+
+      nock(MONEY_ACCOUNT_API_URL_MAP[Env.DEV])
+        .get(`/v1/positions/${MOCK_ADDRESS}`)
+        .reply(200, responseWithExtras);
+
+      const result = await service.fetchPositions(MOCK_ADDRESS);
+      expect(result).toStrictEqual(responseWithExtras);
+      service.destroy();
+    });
+
+    it('accepts unknown fields on interest responses without stripping them', async () => {
+      const { service } = createService(Env.DEV);
+      const responseWithExtras = {
+        ...MOCK_INTEREST_RESPONSE,
+        future_interest_field: 'ok',
+      };
+
+      nock(MONEY_ACCOUNT_API_URL_MAP[Env.DEV])
+        .get(`/v1/positions/${MOCK_ADDRESS}/interest`)
+        .query({
+          vault_address: MOCK_VAULT_ADDRESS,
+          window: '7d',
+        })
+        .reply(200, responseWithExtras);
+
+      const result = await service.fetchInterest(MOCK_ADDRESS, {
+        vaultAddress: MOCK_VAULT_ADDRESS,
+        window: '7d',
+      });
+      expect(result).toStrictEqual(responseWithExtras);
+      service.destroy();
+    });
+
+    it('accepts unknown fields on history responses without stripping them', async () => {
+      const { service } = createService(Env.DEV);
+      const responseWithExtras = {
+        ...MOCK_HISTORY_RESPONSE,
+        future_history_field: 'ok',
+        cash_flows: [
+          {
+            ...MOCK_HISTORY_RESPONSE.cash_flows[0],
+            future_cash_flow_field: 42,
+          },
+        ],
+      };
+
+      nock(MONEY_ACCOUNT_API_URL_MAP[Env.DEV])
+        .get(`/v1/positions/${MOCK_ADDRESS}/history`)
+        .reply(200, responseWithExtras);
+
+      const result = await service.fetchHistory(MOCK_ADDRESS);
+      expect(result).toStrictEqual(responseWithExtras);
+      service.destroy();
+    });
+
+    it('accepts unknown fields on rate-history responses without stripping them', async () => {
+      const { service } = createService(Env.DEV);
+      const responseWithExtras = {
+        ...MOCK_RATE_HISTORY_RESPONSE,
+        future_rate_history_field: 'ok',
+        rates: [
+          {
+            ...MOCK_RATE_HISTORY_RESPONSE.rates[0],
+            future_rate_entry_field: true,
+          },
+          MOCK_RATE_HISTORY_RESPONSE.rates[1],
+        ],
+      };
+
+      nock(MONEY_ACCOUNT_API_URL_MAP[Env.DEV])
+        .get(`/v1/vaults/${MOCK_VAULT_ADDRESS}/rate-history`)
+        .reply(200, responseWithExtras);
+
+      const result = await service.fetchRateHistory(MOCK_VAULT_ADDRESS);
+      expect(result).toStrictEqual(responseWithExtras);
+      service.destroy();
+    });
+
+    it('accepts unknown fields on vault-rate responses without stripping them', async () => {
+      const { service } = createService(Env.DEV);
+      const responseWithExtras = {
+        ...MOCK_VAULT_RATE_RESPONSE,
+        future_vault_rate_field: 'ok',
+      };
+
+      nock(MONEY_ACCOUNT_API_URL_MAP[Env.DEV])
+        .get(`/v1/vaults/${MOCK_VAULT_ADDRESS}/rate`)
+        .reply(200, responseWithExtras);
+
+      const result = await service.fetchVaultRate(MOCK_VAULT_ADDRESS);
+      expect(result).toStrictEqual(responseWithExtras);
+      service.destroy();
+    });
+  });
+
   describe('invalidateQueries', () => {
     it('invalidates cached queries', async () => {
       const { service } = createService(Env.DEV);
diff --git a/packages/money-account-api-data-service/src/structs.ts b/packages/money-account-api-data-service/src/structs.ts
index 995b59b5e40..a6f5e042b2d 100644
--- a/packages/money-account-api-data-service/src/structs.ts
+++ b/packages/money-account-api-data-service/src/structs.ts
@@ -4,14 +4,18 @@ import {
   enums,
   nullable,
   number,
-  object,
   optional,
   string,
+  type,
 } from '@metamask/superstruct';
 
+// Every schema here uses `type()` rather than `object()` so that fields the
+// Money Account API adds later pass validation instead of throwing. Additive
+// backend changes should not be breaking changes for clients.
+
 const DataFreshnessStruct = enums(['live', 'degraded']);
 
-const VaultPositionStruct = object({
+const VaultPositionStruct = type({
   chain_id: number(),
   vault_key: string(),
   name: string(),
@@ -35,7 +39,7 @@ const VaultPositionStruct = object({
 /**
  * One underlying asset in the positions balance breakdown.
  */
-const AssetBalanceStruct = object({
+const AssetBalanceStruct = type({
   asset_contract_address: string(),
   asset_symbol: string(),
   asset_decimals: number(),
@@ -52,7 +56,7 @@ const AssetBalanceStruct = object({
  * `musd_balance`, `vmusd_value_in_musd`, and `total_balance` are mUSD-only
  * and deprecated on the API in favor of `by_asset` and `total_balance_usd`.
  */
-const PositionBalanceStruct = object({
+const PositionBalanceStruct = type({
   musd_balance: string(),
   vmusd_value_in_musd: string(),
   total_balance: string(),
@@ -62,7 +66,7 @@ const PositionBalanceStruct = object({
   total_balance_usd: string(),
 });
 
-export const PositionResponseStruct = object({
+export const PositionResponseStruct = type({
   address: string(),
   as_of_block: number(),
   as_of_timestamp: string(),
@@ -74,7 +78,7 @@ export const PositionResponseStruct = object({
   positions: array(VaultPositionStruct),
 });
 
-export const InterestResponseStruct = object({
+export const InterestResponseStruct = type({
   address: string(),
   vault_address: string(),
   window: string(),
@@ -89,7 +93,7 @@ export const InterestResponseStruct = object({
   indexer_lag_seconds: number(),
 });
 
-const CashFlowEntryStruct = object({
+const CashFlowEntryStruct = type({
   type: enums(['deposit', 'withdraw', 'transfer_in', 'transfer_out']),
   chain_id: number(),
   vault_address: string(),
@@ -110,7 +114,7 @@ const CashFlowEntryStruct = object({
   ]),
 });
 
-export const HistoryResponseStruct = object({
+export const HistoryResponseStruct = type({
   address: string(),
   cash_flows: array(CashFlowEntryStruct),
   next_cursor: nullable(string()),
@@ -121,14 +125,14 @@ export const HistoryResponseStruct = object({
   indexer_lag_seconds: number(),
 });
 
-const RateHistoryEntryStruct = object({
+const RateHistoryEntryStruct = type({
   timestamp: string(),
   block_number: number(),
   rate: string(),
   tx_hash: string(),
 });
 
-export const RateHistoryResponseStruct = object({
+export const RateHistoryResponseStruct = type({
   vault_address: string(),
   chain_id: number(),
   range_start: string(),
@@ -140,7 +144,7 @@ export const RateHistoryResponseStruct = object({
   indexer_lag_seconds: number(),
 });
 
-export const VaultRateResponseStruct = object({
+export const VaultRateResponseStruct = type({
   vault_address: string(),
   chain_id: number(),
   rate: string(),