diff --git a/README.md b/README.md
index 76c3ee8..f3fafbb 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,8 @@ and output an array of arrays for any issues found.
 | --- | --- |
 | [`checkConnectorAccessibleOrientation`](./lib/check-connector-accessible-orientation.ts) | Returns `pcb_accessibility_error` for connectors whose orientation makes them inaccessible. |
 | [`checkAllPinsInComponentAreUnderspecified`](./lib/check-all-pins-in-component-are-underspecified.ts) | Returns `source_component_pins_underspecified_warning` when every pin on a chip lacks pin attributes. |
+| [`checkNoPowerPinDefined`](./lib/check-no-power-pin-defined.ts) | Returns `source_no_power_pin_defined_warning` when a chip has no pin with `requires_power=true`. |
+| [`checkNoGroundPinDefined`](./lib/check-no-ground-pin-defined.ts) | Returns `source_no_ground_pin_defined_warning` when a chip has no pin with `requires_ground=true`. |
 | [`checkDifferentNetViaSpacing`](./lib/check-different-net-via-spacing.ts) | Returns `pcb_via_clearance_error` if vias on different nets are too close together. |
 | [`checkEachPcbPortConnectedToPcbTraces`](./lib/check-each-pcb-port-connected-to-pcb-trace.ts) | Returns `pcb_trace_error` if any `source_port` is not connected to its corresponding PCB traces. |
 | [`checkEachPcbTraceNonOverlapping`](./lib/check-each-pcb-trace-non-overlapping/check-each-pcb-trace-non-overlapping.ts) | Returns `pcb_trace_error` when `pcb_trace` segments overlap incompatible geometry on the same layer. |
@@ -28,9 +30,10 @@ and output an array of arrays for any issues found.
 | Function | Description |
 | --- | --- |
 | [`runAllPlacementChecks`](./lib/run-all-checks.ts) | Runs all placement checks (`checkViasOffBoard`, `checkPcbComponentsOutOfBoard`, `checkPcbComponentOverlap`, and `checkConnectorAccessibleOrientation`). |
-| [`runAllNetlistChecks`](./lib/run-all-checks.ts) | Runs all netlist checks (e.g. `checkPinMustBeConnected`, `checkAllPinsInComponentAreUnderspecified`). |
+| [`runAllNetlistChecks`](./lib/run-all-checks.ts) | Runs netlist connectivity checks (currently `checkPinMustBeConnected`). |
+| [`runAllPinSpecificationChecks`](./lib/run-all-checks.ts) | Runs pin specification checks (e.g. `checkAllPinsInComponentAreUnderspecified`, `checkNoPowerPinDefined`, and `checkNoGroundPinDefined`). |
 | [`runAllRoutingChecks`](./lib/run-all-checks.ts) | Runs all routing checks currently enabled (`checkEachPcbPortConnectedToPcbTraces`, `checkSourceTracesHavePcbTraces`, `checkEachPcbTraceNonOverlapping`, same/different net via spacing, and `checkPcbTracesOutOfBoard`). |
-| [`runAllChecks`](./lib/run-all-checks.ts) | Runs all placement, netlist, and routing checks and returns a combined list of errors. |
+| [`runAllChecks`](./lib/run-all-checks.ts) | Runs placement, netlist, pin specification, and routing checks and returns a combined list of issues. |
 
 ## Implementation Details
 
diff --git a/index.ts b/index.ts
index e6f8f1d..d616603 100644
--- a/index.ts
+++ b/index.ts
@@ -10,9 +10,12 @@ export { checkPcbTracesOutOfBoard } from "./lib/check-trace-out-of-board/checkTr
 export { checkPcbComponentOverlap } from "./lib/check-pcb-components-overlap/checkPcbComponentOverlap"
 export { checkPinMustBeConnected } from "./lib/check-pin-must-be-connected"
 export { checkAllPinsInComponentAreUnderspecified } from "./lib/check-all-pins-in-component-are-underspecified"
+export { checkNoPowerPinDefined } from "./lib/check-no-power-pin-defined"
+export { checkNoGroundPinDefined } from "./lib/check-no-ground-pin-defined"
 export {
   runAllChecks,
   runAllNetlistChecks,
+  runAllPinSpecificationChecks,
   runAllPlacementChecks,
   runAllRoutingChecks,
 } from "./lib/run-all-checks"
diff --git a/lib/check-all-pins-in-component-are-underspecified.ts b/lib/check-all-pins-in-component-are-underspecified.ts
index 48e08c0..57e2f53 100644
--- a/lib/check-all-pins-in-component-are-underspecified.ts
+++ b/lib/check-all-pins-in-component-are-underspecified.ts
@@ -1,22 +1,13 @@
 import { cju } from "@tscircuit/circuit-json-util"
 import type {
   AnyCircuitElement,
+  SourceComponentPinsUnderspecifiedWarning,
   SourcePinAttributes,
   SourcePort,
   SourceComponentBase,
 } from "circuit-json"
 import { source_pin_attributes } from "circuit-json"
 
-type SourceComponentPinsUnderspecifiedWarning = {
-  type: "source_component_pins_underspecified_warning"
-  source_component_pins_underspecified_warning_id: string
-  warning_type: "source_component_pins_underspecified_warning"
-  message: string
-  source_component_id: string
-  source_port_ids: string[]
-  subcircuit_id?: string
-}
-
 const PIN_ATTRIBUTE_KEYS = Object.keys(
   source_pin_attributes.shape,
 ) as (keyof SourcePinAttributes)[]
diff --git a/lib/check-no-ground-pin-defined.ts b/lib/check-no-ground-pin-defined.ts
new file mode 100644
index 0000000..d57fb68
--- /dev/null
+++ b/lib/check-no-ground-pin-defined.ts
@@ -0,0 +1,54 @@
+import { cju } from "@tscircuit/circuit-json-util"
+import type {
+  AnyCircuitElement,
+  SourceComponentBase,
+  SourceNoGroundPinDefinedWarning,
+  SourcePort,
+} from "circuit-json"
+
+/**
+ * Check that each chip has at least one pin marked as requires_ground=true.
+ * Returns warnings for chips where no pin declares requires_ground.
+ */
+export function checkNoGroundPinDefined(
+  circuitJson: AnyCircuitElement[],
+): SourceNoGroundPinDefinedWarning[] {
+  const warnings: SourceNoGroundPinDefinedWarning[] = []
+  const db = cju(circuitJson)
+
+  const sourceComponents = db.source_component.list() as SourceComponentBase[]
+  const sourcePorts = db.source_port.list() as SourcePort[]
+
+  const portsByComponent = new Map<string, SourcePort[]>()
+  for (const port of sourcePorts) {
+    if (!port.source_component_id) continue
+    const existing = portsByComponent.get(port.source_component_id) ?? []
+    existing.push(port)
+    portsByComponent.set(port.source_component_id, existing)
+  }
+
+  for (const component of sourceComponents) {
+    if (component.ftype !== "simple_chip") continue
+
+    const componentPorts =
+      portsByComponent.get(component.source_component_id) ?? []
+    if (componentPorts.length === 0) continue
+
+    const hasRequiredGroundPin = componentPorts.some(
+      (port) => port.requires_ground === true,
+    )
+    if (hasRequiredGroundPin) continue
+
+    warnings.push({
+      type: "source_no_ground_pin_defined_warning",
+      source_no_ground_pin_defined_warning_id: `source_no_ground_pin_defined_warning_${component.source_component_id}`,
+      warning_type: "source_no_ground_pin_defined_warning",
+      message: `${component.name} has no pin with requires_ground=true`,
+      source_component_id: component.source_component_id,
+      source_port_ids: componentPorts.map((port) => port.source_port_id),
+      subcircuit_id: componentPorts[0]?.subcircuit_id,
+    })
+  }
+
+  return warnings
+}
diff --git a/lib/check-no-power-pin-defined.ts b/lib/check-no-power-pin-defined.ts
new file mode 100644
index 0000000..04e54ec
--- /dev/null
+++ b/lib/check-no-power-pin-defined.ts
@@ -0,0 +1,54 @@
+import { cju } from "@tscircuit/circuit-json-util"
+import type {
+  AnyCircuitElement,
+  SourceComponentBase,
+  SourceNoPowerPinDefinedWarning,
+  SourcePort,
+} from "circuit-json"
+
+/**
+ * Check that each chip has at least one pin marked as requires_power=true.
+ * Returns warnings for chips where no pin declares requires_power.
+ */
+export function checkNoPowerPinDefined(
+  circuitJson: AnyCircuitElement[],
+): SourceNoPowerPinDefinedWarning[] {
+  const warnings: SourceNoPowerPinDefinedWarning[] = []
+  const db = cju(circuitJson)
+
+  const sourceComponents = db.source_component.list() as SourceComponentBase[]
+  const sourcePorts = db.source_port.list() as SourcePort[]
+
+  const portsByComponent = new Map<string, SourcePort[]>()
+  for (const port of sourcePorts) {
+    if (!port.source_component_id) continue
+    const existing = portsByComponent.get(port.source_component_id) ?? []
+    existing.push(port)
+    portsByComponent.set(port.source_component_id, existing)
+  }
+
+  for (const component of sourceComponents) {
+    if (component.ftype !== "simple_chip") continue
+
+    const componentPorts =
+      portsByComponent.get(component.source_component_id) ?? []
+    if (componentPorts.length === 0) continue
+
+    const hasRequiredPowerPin = componentPorts.some(
+      (port) => port.requires_power === true,
+    )
+    if (hasRequiredPowerPin) continue
+
+    warnings.push({
+      type: "source_no_power_pin_defined_warning",
+      source_no_power_pin_defined_warning_id: `source_no_power_pin_defined_warning_${component.source_component_id}`,
+      warning_type: "source_no_power_pin_defined_warning",
+      message: `${component.name} has no pin with requires_power=true`,
+      source_component_id: component.source_component_id,
+      source_port_ids: componentPorts.map((port) => port.source_port_id),
+      subcircuit_id: componentPorts[0]?.subcircuit_id,
+    })
+  }
+
+  return warnings
+}
diff --git a/lib/run-all-checks.ts b/lib/run-all-checks.ts
index 7e2898b..a1d0a14 100644
--- a/lib/run-all-checks.ts
+++ b/lib/run-all-checks.ts
@@ -8,6 +8,8 @@ import { checkViasOffBoard } from "./check-pcb-components-out-of-board/checkVias
 import { checkPcbComponentOverlap } from "./check-pcb-components-overlap/checkPcbComponentOverlap"
 import { checkConnectorAccessibleOrientation } from "./check-connector-accessible-orientation"
 import { checkPinMustBeConnected } from "./check-pin-must-be-connected"
+import { checkNoGroundPinDefined } from "./check-no-ground-pin-defined"
+import { checkNoPowerPinDefined } from "./check-no-power-pin-defined"
 import { checkSameNetViaSpacing } from "./check-same-net-via-spacing"
 import { checkSourceTracesHavePcbTraces } from "./check-source-traces-have-pcb-traces"
 import { checkPcbTracesOutOfBoard } from "./check-trace-out-of-board/checkTraceOutOfBoard"
@@ -23,9 +25,16 @@ export async function runAllPlacementChecks(circuitJson: AnyCircuitElement[]) {
 }
 
 export async function runAllNetlistChecks(circuitJson: AnyCircuitElement[]) {
+  return [...checkPinMustBeConnected(circuitJson)]
+}
+
+export async function runAllPinSpecificationChecks(
+  circuitJson: AnyCircuitElement[],
+) {
   return [
-    ...checkPinMustBeConnected(circuitJson),
     ...checkAllPinsInComponentAreUnderspecified(circuitJson),
+    ...checkNoPowerPinDefined(circuitJson),
+    ...checkNoGroundPinDefined(circuitJson),
   ]
 }
 
@@ -45,6 +54,7 @@ export async function runAllChecks(circuitJson: AnyCircuitElement[]) {
   return [
     ...(await runAllPlacementChecks(circuitJson)),
     ...(await runAllNetlistChecks(circuitJson)),
+    ...(await runAllPinSpecificationChecks(circuitJson)),
     ...(await runAllRoutingChecks(circuitJson)),
   ]
 }
diff --git a/package.json b/package.json
index 0af3cac..335907c 100644
--- a/package.json
+++ b/package.json
@@ -19,7 +19,7 @@
     "@types/debug": "^4.1.12",
     "bun-match-svg": "^0.0.11",
     "circuit-to-svg": "^0.0.333",
-    "circuit-json": "^0.0.392",
+    "circuit-json": "^0.0.395",
     "debug": "^4.3.5",
     "tscircuit": "^0.0.1439",
     "zod": "^3.23.8",
diff --git a/tests/lib/check-no-ground-pin-defined.test.ts b/tests/lib/check-no-ground-pin-defined.test.ts
new file mode 100644
index 0000000..24f6a7c
--- /dev/null
+++ b/tests/lib/check-no-ground-pin-defined.test.ts
@@ -0,0 +1,90 @@
+import { describe, expect, test } from "bun:test"
+import type { AnyCircuitElement } from "circuit-json"
+import { checkNoGroundPinDefined } from "lib/check-no-ground-pin-defined"
+
+describe("checkNoGroundPinDefined", () => {
+  test("returns warning when chip has no requires_ground pin", () => {
+    const circuitJson: AnyCircuitElement[] = [
+      {
+        type: "source_component",
+        source_component_id: "component_1",
+        name: "U1",
+        ftype: "simple_chip",
+      },
+      {
+        type: "source_port",
+        source_port_id: "port_1",
+        source_component_id: "component_1",
+        name: "IO1",
+      },
+      {
+        type: "source_port",
+        source_port_id: "port_2",
+        source_component_id: "component_1",
+        name: "IO2",
+      },
+    ]
+
+    const warnings = checkNoGroundPinDefined(circuitJson)
+    expect(warnings).toHaveLength(1)
+    expect(warnings[0].type).toBe("source_no_ground_pin_defined_warning")
+    expect(warnings[0].warning_type).toBe(
+      "source_no_ground_pin_defined_warning",
+    )
+    expect(warnings[0].source_component_id).toBe("component_1")
+  })
+
+  test("returns no warning when at least one pin has requires_ground=true", () => {
+    const circuitJson: AnyCircuitElement[] = [
+      {
+        type: "source_component",
+        source_component_id: "component_1",
+        name: "U1",
+        ftype: "simple_chip",
+      },
+      {
+        type: "source_port",
+        source_port_id: "port_1",
+        source_component_id: "component_1",
+        name: "GND",
+        requires_ground: true,
+      },
+      {
+        type: "source_port",
+        source_port_id: "port_2",
+        source_component_id: "component_1",
+        name: "IO2",
+      },
+    ]
+
+    const warnings = checkNoGroundPinDefined(circuitJson)
+    expect(warnings).toHaveLength(0)
+  })
+
+  test("ignores non-chip components", () => {
+    const circuitJson: AnyCircuitElement[] = [
+      {
+        type: "source_component",
+        source_component_id: "component_1",
+        name: "R1",
+        ftype: "simple_resistor",
+        resistance: 1000,
+      },
+      {
+        type: "source_port",
+        source_port_id: "port_1",
+        source_component_id: "component_1",
+        name: "pos",
+      },
+      {
+        type: "source_port",
+        source_port_id: "port_2",
+        source_component_id: "component_1",
+        name: "neg",
+      },
+    ]
+
+    const warnings = checkNoGroundPinDefined(circuitJson)
+    expect(warnings).toHaveLength(0)
+  })
+})
diff --git a/tests/lib/check-no-power-pin-defined.test.ts b/tests/lib/check-no-power-pin-defined.test.ts
new file mode 100644
index 0000000..de50abb
--- /dev/null
+++ b/tests/lib/check-no-power-pin-defined.test.ts
@@ -0,0 +1,88 @@
+import { describe, expect, test } from "bun:test"
+import type { AnyCircuitElement } from "circuit-json"
+import { checkNoPowerPinDefined } from "lib/check-no-power-pin-defined"
+
+describe("checkNoPowerPinDefined", () => {
+  test("returns warning when chip has no requires_power pin", () => {
+    const circuitJson: AnyCircuitElement[] = [
+      {
+        type: "source_component",
+        source_component_id: "component_1",
+        name: "U1",
+        ftype: "simple_chip",
+      },
+      {
+        type: "source_port",
+        source_port_id: "port_1",
+        source_component_id: "component_1",
+        name: "IO1",
+      },
+      {
+        type: "source_port",
+        source_port_id: "port_2",
+        source_component_id: "component_1",
+        name: "IO2",
+      },
+    ]
+
+    const warnings = checkNoPowerPinDefined(circuitJson)
+    expect(warnings).toHaveLength(1)
+    expect(warnings[0].type).toBe("source_no_power_pin_defined_warning")
+    expect(warnings[0].warning_type).toBe("source_no_power_pin_defined_warning")
+    expect(warnings[0].source_component_id).toBe("component_1")
+  })
+
+  test("returns no warning when at least one pin has requires_power=true", () => {
+    const circuitJson: AnyCircuitElement[] = [
+      {
+        type: "source_component",
+        source_component_id: "component_1",
+        name: "U1",
+        ftype: "simple_chip",
+      },
+      {
+        type: "source_port",
+        source_port_id: "port_1",
+        source_component_id: "component_1",
+        name: "VCC",
+        requires_power: true,
+      },
+      {
+        type: "source_port",
+        source_port_id: "port_2",
+        source_component_id: "component_1",
+        name: "IO2",
+      },
+    ]
+
+    const warnings = checkNoPowerPinDefined(circuitJson)
+    expect(warnings).toHaveLength(0)
+  })
+
+  test("ignores non-chip components", () => {
+    const circuitJson: AnyCircuitElement[] = [
+      {
+        type: "source_component",
+        source_component_id: "component_1",
+        name: "R1",
+        ftype: "simple_resistor",
+        resistance: 1000,
+      },
+      {
+        type: "source_port",
+        source_port_id: "port_1",
+        source_component_id: "component_1",
+        name: "pos",
+      },
+      {
+        type: "source_port",
+        source_port_id: "port_2",
+        source_component_id: "component_1",
+        name: "neg",
+      },
+    ]
+
+    const warnings = checkNoPowerPinDefined(circuitJson)
+    expect(warnings).toHaveLength(0)
+  })
+})
diff --git a/tests/lib/run-all-checks.test.ts b/tests/lib/run-all-checks.test.ts
index 7f9b2dc..233a8d6 100644
--- a/tests/lib/run-all-checks.test.ts
+++ b/tests/lib/run-all-checks.test.ts
@@ -2,6 +2,7 @@ import { expect, test } from "bun:test"
 import {
   runAllChecks,
   runAllNetlistChecks,
+  runAllPinSpecificationChecks,
   runAllPlacementChecks,
   runAllRoutingChecks,
 } from "../.." // index.ts when imported from root
@@ -82,7 +83,7 @@ test("runAllNetlistChecks excludes routing-only pcb trace connectivity checks",
   expect(netlistErrors).toEqual([])
   expect(routingErrors.length).toBeGreaterThan(0)
 })
-test("runAllChecks equals placement + netlist + routing checks", async () => {
+test("runAllChecks equals placement + netlist + pin specification + routing checks", async () => {
   const circuitJson: AnyCircuitElement[] = [
     {
       type: "pcb_board",
@@ -158,11 +159,13 @@ test("runAllChecks equals placement + netlist + routing checks", async () => {
   const allChecksErrors = await runAllChecks(circuitJson)
   const placementErrors = await runAllPlacementChecks(circuitJson)
   const netlistErrors = await runAllNetlistChecks(circuitJson)
+  const pinSpecificationErrors = await runAllPinSpecificationChecks(circuitJson)
   const routingErrors = await runAllRoutingChecks(circuitJson)
 
   expect(allChecksErrors).toEqual([
     ...placementErrors,
     ...netlistErrors,
+    ...pinSpecificationErrors,
     ...routingErrors,
   ])
 })
diff --git a/tests/lib/user-circuit-netlist.test.tsx b/tests/lib/user-circuit-netlist.test.tsx
index 3716b5d..920cd69 100644
--- a/tests/lib/user-circuit-netlist.test.tsx
+++ b/tests/lib/user-circuit-netlist.test.tsx
@@ -65,6 +65,8 @@ test("test.tsx builds and has no netlist errors", async () => {
         name="USBC"
         pinAttributes={{
           GND1: { mustBeConnected: false },
+          VBUS1: { requiresPower: true },
+          A4: { requiresPower: true },
         }}
         connections={{
           GND1: "net.GND",
@@ -90,6 +92,7 @@ test("test.tsx builds and has no netlist errors", async () => {
 
   const circuitJson = circuit.getCircuitJson()
 
-  const netlistErrors = await runAllNetlistChecks(circuitJson as any)
+  const netlistIssues = await runAllNetlistChecks(circuitJson)
+  const netlistErrors = netlistIssues.filter((issue) => "error_type" in issue)
   expect(netlistErrors).toEqual([])
 })