diff --git a/litellm/proxy/hooks/parallel_request_limiter_v3.py b/litellm/proxy/hooks/parallel_request_limiter_v3.py
index 1e65da5b867..d1fb03fd7e6 100644
--- a/litellm/proxy/hooks/parallel_request_limiter_v3.py
+++ b/litellm/proxy/hooks/parallel_request_limiter_v3.py
@@ -12,6 +12,7 @@ from collections.abc import Callable, Mapping, Sequence, Set
 from contextvars import ContextVar
 from dataclasses import dataclass, field
 from datetime import datetime
+from types import MappingProxyType
 from typing import (
     TYPE_CHECKING,
     Any,
@@ -2020,7 +2021,7 @@ class _PROXY_MaxParallelRequestsHandler_v3(CustomLogger):
 
     async def reserve_tpm_tokens(
         self,
-        descriptors: list[RateLimitDescriptor],
+        descriptors: Sequence[RateLimitDescriptor],
         estimated_tokens: int,
         parent_otel_span: Span | None = None,
     ) -> RateLimitResponse:
@@ -2806,6 +2807,21 @@ class _PROXY_MaxParallelRequestsHandler_v3(CustomLogger):
 
         return descriptors
 
+    @staticmethod
+    def _deduplicate_descriptors(
+        descriptors: Sequence[RateLimitDescriptor],
+    ) -> tuple[RateLimitDescriptor, ...]:
+        """
+        Collapse descriptors repeating a (key, value) pair into one entry.
+
+        A descriptor identifies one counter, and every consumer below charges
+        the request once per descriptor it is given. A repeat therefore
+        increments the sliding window twice and reserves TPM tokens twice
+        against that same counter, halving the limit the operator configured.
+        """
+        by_identity: Final = MappingProxyType({(d["key"], d["value"]): d for d in descriptors})
+        return tuple(by_identity.values())
+
     async def _check_model_has_recent_failures(
         self,
         model: str,
@@ -3000,7 +3016,7 @@ class _PROXY_MaxParallelRequestsHandler_v3(CustomLogger):
     def _handle_rate_limit_error(
         self,
         response: RateLimitResponse,
-        descriptors: list[RateLimitDescriptor],
+        descriptors: Sequence[RateLimitDescriptor],
         requested_model: str | None = None,
     ) -> None:
         """Handle rate limit exceeded by raising :class:`ProxyRateLimitError` (a 429)."""
@@ -3427,7 +3443,7 @@ class _PROXY_MaxParallelRequestsHandler_v3(CustomLogger):
             )
 
         # Create rate limit descriptors
-        descriptors: Final = self._create_rate_limit_descriptors(
+        assembled_descriptors: Final = self._create_rate_limit_descriptors(
             user_api_key_dict=user_api_key_dict,
             data=data,
             rpm_limit_type=rpm_limit_type,
@@ -3440,23 +3456,25 @@ class _PROXY_MaxParallelRequestsHandler_v3(CustomLogger):
         self._add_team_model_rate_limit_descriptor_from_metadata(
             user_api_key_dict=user_api_key_dict,
             requested_model=requested_model,
-            descriptors=descriptors,
+            descriptors=assembled_descriptors,
         )
 
         # Project Level Rate Limits
         self._add_project_model_rate_limit_descriptor_from_metadata(
             user_api_key_dict=user_api_key_dict,
             requested_model=requested_model,
-            descriptors=descriptors,
+            descriptors=assembled_descriptors,
         )
         self.add_project_io_token_rate_limit_descriptors_from_metadata(
             user_api_key_dict=user_api_key_dict,
             requested_model=requested_model,
-            descriptors=descriptors,
+            descriptors=assembled_descriptors,
         )
 
         # Org Level Rate Limits
-        descriptors.extend(self.create_organization_rate_limit_descriptor(user_api_key_dict, requested_model))
+        assembled_descriptors.extend(self.create_organization_rate_limit_descriptor(user_api_key_dict, requested_model))
+
+        descriptors: Final = self._deduplicate_descriptors(assembled_descriptors)
 
         # Only check rate limits if we have descriptors with actual limits
         if descriptors:
diff --git a/tests/test_litellm/proxy/hooks/test_parallel_request_limiter_v3.py b/tests/test_litellm/proxy/hooks/test_parallel_request_limiter_v3.py
index fc0088b28d7..6e8d680826a 100644
--- a/tests/test_litellm/proxy/hooks/test_parallel_request_limiter_v3.py
+++ b/tests/test_litellm/proxy/hooks/test_parallel_request_limiter_v3.py
@@ -20,6 +20,7 @@ from litellm.caching.caching import DualCache
 from litellm.constants import INTERNAL_CALL_ORIGIN_METADATA_KEY
 from litellm.proxy._types import UserAPIKeyAuth
 from litellm.proxy.hooks.parallel_request_limiter_v3 import (
+    CHECK_AND_INCREMENT_BY_N_SCRIPT,
     PARALLEL_REQUEST_SLOT_TTL_SECONDS,
     ParallelSlotAcquisition,
     RequestRateLimiterStash,
@@ -6004,3 +6005,243 @@ async def test_success_hook_leaves_stash_untouched_for_non_batch_responses():
         data={}, user_api_key_dict=user, response=ModelResponse(usage=Usage(total_tokens=5))
     )
     assert get_request_stash().batch_enqueued_reservation == reservation
+
+
+def _team_model_limit_auth(api_key: str, team_id: str, **limits) -> UserAPIKeyAuth:
+    return UserAPIKeyAuth(
+        api_key=hash_token(api_key),
+        team_id=team_id,
+        team_metadata=dict(limits),
+    )
+
+
+async def _counter_value(handler, counter_key: str) -> int:
+    raw = await handler.internal_usage_cache.async_get_cache(
+        key=counter_key, litellm_parent_otel_span=None, local_only=True
+    )
+    return int(raw or 0)
+
+
+class _RecordingUsageCache(InternalUsageCache):
+    """
+    Injected in place of the handler's usage cache so a test can see which counter
+    keys one request charges, without replacing methods on the handler itself.
+    """
+
+    def __init__(self, dual_cache: DualCache):
+        super().__init__(dual_cache)
+        self.batched_key_reads: List[List[str]] = []
+
+    async def async_batch_get_cache(
+        self,
+        keys,
+        parent_otel_span=None,
+        local_only: bool = False,
+    ):
+        self.batched_key_reads.append([k for k in keys if k is not None])
+        return await super().async_batch_get_cache(
+            keys=keys, parent_otel_span=parent_otel_span, local_only=local_only
+        )
+
+
+def test_deduplicate_descriptors_collapses_repeats_keeping_limits_v3():
+    """
+    The dedup helper keeps one entry per (key, value), preserves its rate_limit
+    and leaves distinct descriptors and their order alone.
+    """
+    limits = {"requests_per_unit": 10, "tokens_per_unit": 100000, "window_size": 60}
+    team = {"key": "model_per_team", "value": "team-dup:gpt-4", "rate_limit": limits}
+    key_scoped = {"key": "model_per_key", "value": "sk-hash:gpt-4", "rate_limit": limits}
+
+    deduped = _PROXY_MaxParallelRequestsHandler._deduplicate_descriptors(
+        [team, key_scoped, dict(team)]
+    )
+
+    assert [(d["key"], d["value"]) for d in deduped] == [
+        ("model_per_team", "team-dup:gpt-4"),
+        ("model_per_key", "sk-hash:gpt-4"),
+    ]
+    assert deduped[0]["rate_limit"]["requests_per_unit"] == 10
+    assert deduped[0]["rate_limit"]["tokens_per_unit"] == 100000
+
+
+@pytest.mark.asyncio
+async def test_model_per_team_counter_charged_once_from_team_metadata_v3():
+    """
+    Regression test: team_metadata model limits must charge their counter once.
+
+    They were appended twice, once inside _create_rate_limit_descriptors and once
+    by _add_team_model_rate_limit_descriptor_from_metadata, so the same counter key
+    landed in one batch read twice and every request incremented it by 2.
+
+    The usage cache is injected rather than patched onto the handler, so the real
+    rate-limit path runs and the test observes it through a real collaborator.
+    """
+    usage_cache = _RecordingUsageCache(DualCache())
+    handler = _PROXY_MaxParallelRequestsHandler(internal_usage_cache=usage_cache)
+
+    user_api_key_dict = _team_model_limit_auth(
+        "sk-team-dup", "team-dup", model_rpm_limit={"gpt-4": 10}
+    )
+
+    await handler.async_pre_call_hook(
+        user_api_key_dict=user_api_key_dict,
+        cache=usage_cache.dual_cache,
+        data={"model": "gpt-4", "messages": [{"role": "user", "content": "hi"}]},
+        call_type="",
+    )
+
+    counter_key = handler.create_rate_limit_keys(
+        "model_per_team", "team-dup:gpt-4", "requests"
+    )
+    charged = [read.count(counter_key) for read in usage_cache.batched_key_reads]
+    assert any(
+        count > 0 for count in charged
+    ), f"model_per_team was never charged; reads={usage_cache.batched_key_reads}"
+    assert all(
+        count <= 1 for count in charged
+    ), f"model_per_team charged more than once in a single read: {charged}"
+
+
+@pytest.mark.asyncio
+async def test_model_per_team_rpm_counter_increments_once_per_request_v3():
+    """
+    Regression test: one request must add exactly 1 to the team per-model RPM
+    counter. The duplicate descriptor put the same counter key into
+    keys_to_fetch twice, so the sliding window incremented it by 2 and the
+    configured RPM was enforced at half its value.
+    """
+    local_cache = DualCache()
+    handler = _PROXY_MaxParallelRequestsHandler(
+        internal_usage_cache=InternalUsageCache(local_cache)
+    )
+    assert (
+        handler.batch_rate_limiter_script is None
+    ), "Test premise: no Redis, so the in-memory sliding window does the increment"
+
+    user_api_key_dict = _team_model_limit_auth(
+        "sk-team-count", "team-count", model_rpm_limit={"gpt-4": 100}
+    )
+    counter_key = handler.create_rate_limit_keys(
+        "model_per_team", "team-count:gpt-4", "requests"
+    )
+
+    for expected_count in (1, 2):
+        await handler.async_pre_call_hook(
+            user_api_key_dict=user_api_key_dict,
+            cache=local_cache,
+            data={"model": "gpt-4", "messages": [{"role": "user", "content": "hi"}]},
+            call_type="",
+        )
+        assert await _counter_value(handler, counter_key) == expected_count
+
+
+class _ScriptRegisteringRedisCache:
+    """
+    Stand-in for RedisCache carrying only what the handler's constructor uses:
+    it registers Lua scripts. Injecting it through DualCache makes the handler
+    wire up its own Redis reservation path, so the test drives that path without
+    assigning anything onto the handler.
+    """
+
+    def __init__(self, store: Dict[str, int]):
+        self._store = store
+
+    def async_register_script(self, script: str):
+        if script is CHECK_AND_INCREMENT_BY_N_SCRIPT:
+            return _fake_check_and_increment_script(self._store)
+        return None
+
+
+def _fake_check_and_increment_script(store: Dict[str, int]):
+    """
+    Stand-in for CHECK_AND_INCREMENT_BY_N_LUA with the Redis INCRBY semantics
+    the real script has. The in-memory fallback snapshots every counter before
+    writing any, so a repeated descriptor there silently overwrites instead of
+    accumulating; only this path shows the double reservation.
+    """
+
+    async def script(keys: List[str], args: List[int]) -> List[int]:
+        results: List[int] = [0]
+        for i in range(0, len(keys), 2):
+            window_key = keys[i]
+            counter_key = keys[i + 1]
+            increment = int(args[(i // 2) * 4 + 1])
+            if window_key in store:
+                store[counter_key] = store.get(counter_key, 0) + increment
+            else:
+                store[window_key] = 0
+                store[counter_key] = increment
+            results.extend([store[counter_key], store[window_key]])
+        return results
+
+    return script
+
+
+@pytest.mark.asyncio
+async def test_model_per_team_tpm_reserved_once_per_request_v3():
+    """
+    Regression test: the atomic TPM reservation must charge the team per-model
+    token counter once. reserve_tpm_tokens emits one increment per descriptor
+    and the Redis path INCRBYs each in turn, so the duplicate descriptor
+    reserved the estimate twice and halved the effective TPM.
+    """
+    redis_store: Dict[str, int] = {}
+    local_cache = DualCache(redis_cache=_ScriptRegisteringRedisCache(redis_store))
+    handler = _PROXY_MaxParallelRequestsHandler(
+        internal_usage_cache=InternalUsageCache(local_cache)
+    )
+    assert handler.tpm_reservation_enabled, "Test premise: reservation path is on"
+
+    user_api_key_dict = _team_model_limit_auth(
+        "sk-team-tpm", "team-tpm", model_tpm_limit={"gpt-4": 100000}
+    )
+    tokens_key = handler.create_rate_limit_keys(
+        "model_per_team", "team-tpm:gpt-4", "tokens"
+    )
+
+    pre_call_data = {
+        "model": "gpt-4",
+        "messages": [{"role": "user", "content": "hi"}],
+        "max_tokens": 5,
+    }
+    expected_reservation = handler._estimate_tokens_for_request(data=pre_call_data)
+    assert expected_reservation > 0, "Test premise: something must be reserved"
+
+    await handler.async_pre_call_hook(
+        user_api_key_dict=user_api_key_dict,
+        cache=local_cache,
+        data=dict(pre_call_data),
+        call_type="",
+    )
+
+    assert redis_store[tokens_key] == expected_reservation
+
+
+@pytest.mark.asyncio
+async def test_model_per_key_rpm_counter_increments_once_per_request_v3():
+    """
+    Guard that the model_per_key path, which was never duplicated, still
+    charges its counter exactly once after the model_per_team dedup.
+    """
+    local_cache = DualCache()
+    handler = _PROXY_MaxParallelRequestsHandler(
+        internal_usage_cache=InternalUsageCache(local_cache)
+    )
+    api_key = hash_token("sk-key-count")
+    user_api_key_dict = UserAPIKeyAuth(
+        api_key=api_key,
+        metadata={"model_rpm_limit": {"gpt-4": 100}},
+    )
+    counter_key = handler.create_rate_limit_keys(
+        "model_per_key", f"{api_key}:gpt-4", "requests"
+    )
+
+    for expected_count in (1, 2):
+        await handler.async_pre_call_hook(
+            user_api_key_dict=user_api_key_dict,
+            cache=local_cache,
+            data={"model": "gpt-4", "messages": [{"role": "user", "content": "hi"}]},
+            call_type="",
+        )
+        assert await _counter_value(handler, counter_key) == expected_count