---
title: "POST /#Action=ModifyDBSubnetGroup"
method: POST
path: "/#Action=ModifyDBSubnetGroup"
---

# POST /#Action=ModifyDBSubnetGroup

`POST /#Action=ModifyDBSubnetGroup`

Modifies an existing DB subnet group. DB subnet groups must contain at least one subnet in at least two AZs in the Amazon Region.

## Query parameters

- `Action` 'ModifyDBSubnetGroup', required
- `Version` '2014-10-31', required

## Response `200`

Success

## Other responses

- `480` — DBSubnetGroupNotFoundFault
- `481` — DBSubnetQuotaExceededFault
- `482` — SubnetAlreadyInUse
- `483` — DBSubnetGroupDoesNotCoverEnoughAZs
- `484` — InvalidSubnet

---

[API](https://skmtc.net/aws/apis/neptune.md) · [All operations](https://skmtc.net/aws/apis/neptune/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/aws/neptune/versions/c3673ca75718/schema)