Source: https://guthlabs.ai/docs/instruments/irs-contribution-limit-lookup-401k-ira-hsa/
instrument / verified-clean
# IRS Contribution Limit Lookup (401k/IRA/HSA)
The current ledger marks this instrument verified clean within the source-bound verification corpus.
Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**
## Inspectable records
[01**Overview**Purpose and lifecycle]()[02**Mechanism**Method and assumptions]()[03**Implementation**Binding and validation]()[04**Qualification**Evidence and errata]()
## Ledger state
The current ledger marks this instrument verified clean within the source-bound verification corpus.
**Area**: Finance, Economics & Business (educational only — never individualized investment, tax, or legal advice)
**Tranche**: tranche-7
**Evidence ID**: t7-104
**Ledger rows**: 1
No ledger note is attached.
## Review findings
The conditional lookup concept is standard, but the supplied specification needs an explicit schema for coverage type, base versus total limit semantics, account-specific catch-up rules, eligibility, and year-dated table contents. The displayed vectors use exact 2024 IRS table entries and do not require interpolation.
### Formula and scope findings
- The lookup structure is appropriate, but limit=table[account_type][year][catch_up_flag] is ambiguous: it does not state whether limit is the base statutory limit or the total including catch-up.
- Account type alone is insufficient for HSA lookup; 2024 HSA limits differ for self-only versus family coverage.
- Catch-up eligibility is not determined solely by age for every account: HSA catch-up begins at age 55, while 401(k) and IRA catch-up generally begin at age 50; plan availability and eligibility constraints also apply.
- FSA has an annual statutory limit but no age-based catch-up, so catch_up_flag must support a not-applicable or zero value.
- The actual year-dated IRS data table is not included in the supplied spec, so the instrument cannot operate offline until the table bundle is provided and versioned.
### Unit assumptions
- All dollar amounts are annual U.S. federal contribution limits in nominal USD for the specified tax year.
- Age is the taxpayer or participant's age during the tax year; boundary ages are inclusive: 50+ for 401(k)/IRA catch-up and 55+ for HSA catch-up.
- The vectors define annual_limit as the base limit excluding catch-up, catch_up_limit as the additional permitted amount, and total_maximum as their sum.
- The HSA vectors require coverage_type to distinguish self-only from family coverage.
- These are statutory federal limits; an employer plan, eligibility rule, compensation limit, or individual circumstances can impose a lower usable amount.
## Boundary hardening
**BREAK_CLAIMED** · SELF_FLAGGED
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.
## Errata and corrections
No applied erratum is attached to this unique-name record.
## Inspectable example
4 review vectors are recorded. One source-bound sample is shown below.
````
{
"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."
}
````
## Related workflows
No source-defined multi-instrument workflow membership is recorded.
## Sources and evidence
These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.
- `VERIFIED_LEDGER.json · VERIFIED_CLEAN`
- `evidence-tranche7/tranche7-results.json`
- `BOUNDARY_HAZARD_CATALOG.json`