IRS Contribution Limit Lookup (401k/IRA/HSA) implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t7-104

Effect

Computation or source lookup only

Input and validation requirements

An unsupported tax year produces an undefined lookup result, and age-date interpretation can select different catch-up branches unless the convention is explicitly specified.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "account_type": "401k",
    "tax_year": 2024,
    "age": 49
  },
  "expected_outputs": {
    "annual_limit_usd": 23000,
    "catch_up_limit_usd": 0,
    "total_maximum_usd": 23000
  },
  "reference_data": {
    "account_type": "401k",
    "tax_year": 2024,
    "base_limit_usd": 23000,
    "catch_up_age": 50,
    "catch_up_limit_usd": 7500,
    "source_convention": "IRS 2024 published retirement-plan limits, IRS Notice 2023-75"
  },
  "working": "Age 49 is below the inclusive catch-up threshold of 50, so catch_up_limit = 0. annual_limit = 23,000. total_maximum = 23,000 + 0 = 23,000 USD."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche7/tranche7-results.json