diff --git a/__tests__/pages/api/benefits.test.ts b/__tests__/pages/api/benefits.test.ts
index 9f4e898bd..7a320684c 100644
--- a/__tests__/pages/api/benefits.test.ts
+++ b/__tests__/pages/api/benefits.test.ts
@@ -433,6 +433,28 @@ describe('consolidated benefit tests: eligible: 65+', () => {
     expectAlwAfsTooOld(res)
   })
 
+  it('returns "eligible" - single, 20 years in Canada, high income (partial gis edge case)', async () => {
+    const res = await mockGetRequest({
+      incomeAvailable: true,
+      income: 100000,
+      ...age65NoDefer,
+      maritalStatus: MaritalStatus.SINGLE,
+      livingCountry: LivingCountry.CANADA,
+      legalStatus: LegalStatus.CANADIAN_CITIZEN,
+      livedOutsideCanada: true,
+      yearsInCanadaSince18: 20,
+      everLivedSocialCountry: undefined,
+      ...partnerUndefined,
+    })
+    expectOasGisEligible(
+      res,
+      EntitlementResultType.PARTIAL,
+      roundToTwo(legalValues.oas.amount / 2),
+      324.34
+    )
+    expectAlwAfsTooOld(res)
+  })
+
   it('returns "eligible" - single, living in Agreement, 20 years in Canada', async () => {
     const res = await mockGetRequest({
       ...income10k,
diff --git a/i18n/api/en.ts b/i18n/api/en.ts
index 16691819e..59c2da1bd 100644
--- a/i18n/api/en.ts
+++ b/i18n/api/en.ts
@@ -310,6 +310,6 @@ const en: Translations = {
   },
   yes: 'Yes',
   no: 'No',
-  years: 'years',
+  year: 'year',
 }
 export default en
diff --git a/i18n/api/fr.ts b/i18n/api/fr.ts
index 2cc85c039..49b7a6686 100644
--- a/i18n/api/fr.ts
+++ b/i18n/api/fr.ts
@@ -327,6 +327,6 @@ const fr: Translations = {
   },
   yes: 'Oui',
   no: 'Non',
-  years: 'ans',
+  year: 'an',
 }
 export default fr
diff --git a/i18n/api/index.ts b/i18n/api/index.ts
index 02037f5e3..144e6c71d 100644
--- a/i18n/api/index.ts
+++ b/i18n/api/index.ts
@@ -117,7 +117,7 @@ export interface Translations {
   }
   yes: string
   no: string
-  years: string
+  year: string
 }
 
 export function getTranslations(language: Language): Translations {
diff --git a/utils/api/benefits/entitlementFormula.ts b/utils/api/benefits/entitlementFormula.ts
index 95c3f764d..53bc63e40 100644
--- a/utils/api/benefits/entitlementFormula.ts
+++ b/utils/api/benefits/entitlementFormula.ts
@@ -182,9 +182,10 @@ export class EntitlementFormula {
       this.calculationMethod === 'LOW'
         ? 3
         : 1
-    return roundToTwo(
+    const calculated = roundToTwo(
       this.actualMaxAmount - this.incomeDifferential * differentialMultiplier
     )
+    return Math.max(0, calculated)
   }
 
   /**
diff --git a/utils/api/definitions/textReplacementRules.ts b/utils/api/definitions/textReplacementRules.ts
index 5fca3a317..3528299d2 100644
--- a/utils/api/definitions/textReplacementRules.ts
+++ b/utils/api/definitions/textReplacementRules.ts
@@ -26,10 +26,12 @@ export const textReplacementRules: TextReplacementRules = {
       handler.benefitResults.oas?.entitlement.deferral.increase ?? 0,
       handler.translations._locale
     )}</strong>`,
-  OAS_DEFERRAL_YEARS: (handler) =>
-    `<strong>${String(
-      handler.benefitResults.oas?.entitlement.deferral.years ?? 0
-    )} ${handler.translations.years}</strong>`,
+  OAS_DEFERRAL_YEARS: (handler) => {
+    const years = handler.benefitResults.oas?.entitlement.deferral.years
+    return `<strong>${years ?? 0} ${handler.translations.year}${
+      years !== 1 ? 's' : ''
+    }</strong>`
+  },
   OAS_DEFERRAL_AGE: (handler) =>
     String(handler.benefitResults.oas.entitlement.deferral.age),
   OAS_CLAWBACK: (handler) =>