NAT Gateway Cost

I. Formal Definition

The combined cost of network address translation gateway resources, including hourly charges and per-gigabyte data processing fees, used to provide outbound internet access to private subnet workloads. NAT gateway cost is one of the highest-margin cloud network charges and a frequent FinOps target. The federation requires NAT gateway traffic to be reported per workload with data-processing volume separated from gateway-hour charges. Workloads with sustained heavy egress through NAT are evaluated for VPC endpoint or gateway endpoint alternatives under UFMS-001:2.4.

II. Etymology

A combination of NAT, an IP networking acronym, and gateway, a router topology term; the cost-aware sense stabilised in the FinOps Foundation literature.

III. Federation Usage

Federation members publish NAT gateway cost per workload quarterly. Heavy-egress workloads are evaluated for endpoint alternatives. Optimisation actions are tracked in the FinOps register under MEV-Annex:3.2 and reconciled to actual savings.

IV. Related Terms

• public-ipv4-cost
• egress-waste
• transit-pricing
• intra-region-transfer

V. Authoritative Citations

• UFMS-001:2.4UFMS Article II - NAT Gateway
• MEV-Annex:3.2MEV Annex III - NAT Cost Reporting

VI. Citation in BibTeX

@misc{ifo4_glossary_nat_gateway_cost,
  title        = {{NAT Gateway Cost}},
  author       = {{IFO4 Federation Editorial Board}},
  howpublished = {{IFO4 Federation Glossary, slug \texttt{nat-gateway-cost}}},
  year         = {2026},
  url          = {https://ifo4.org/glossary/nat-gateway-cost},
  note         = {Category: FinOps; key: NATGatewayCost}
}

VII. Challenge This Definition

Federation members and accredited practitioners may challenge any entry under TGS-002:1.7. Filed challenges are routed to the editorial board, triaged into the revision register, and resolved in writing on the public docket. The slug remains stable through any revision.