How it works
Methodology and sources
A plain-language walkthrough of the calculation engine. The authoritative rules live in 34 CFR 685.203 and the annual Federal Student Aid COD Technical Reference; this page does not replace them.
- Engine version
- 1.3.1
- Policy year
- 2026-27
- Sources reviewed
- 2026-07-23
- Release
- sor-v56-1.3.1-2026-08-03
The calculation, step by step
1. Establish baselines
Resolve the Subsidized and Unsubsidized annual anchors for the student's grade level and dependency status, per the 34 CFR 685.203 schedule. For 2026-27 without a loan limit exception, the OBBBA table applies.
2. Resolve the combined limit
Compute the effective combined limit, accounting for additional unsubsidized eligibility where it applies.
3. Compute the SOR percentage
Weight enrolled credits against the academic-year full-time denominator and round to the policy-specified precision. The result is reported as the SOR percentage.
4. Apply the reduction
Multiply the annual pools by the SOR percentage to produce reduced Subsidized, Unsubsidized, and (where modelled) Grad PLUS annual amounts.
5. Distribute across the loan period
Split reduced pools across terms either equally or proportionally. Proportional distribution uses effective enrolled-credit weighting.
6. Surface caveats
Warnings are produced by the engine itself, not the interface, so the API and every screen report the same limitations. Less-than-half-time (LT-HT) enrollment, NSLDS aggregate and lifetime checks, and pending federal guidance are all flagged explicitly.
Documented caveats
- This tool produces estimates. It is not an award, approval, or guarantee, and it does not perform COD origination or read NSLDS records.
- Where 2026-27 behaviour depends on rulemaking implementing OBBBA, items are flagged as pending federal guidance in the public source register.
- Department proportional-distribution evidence is marked as caveated because the source workbook labels and formulas conflict.
- Grad PLUS for non-grandfathered 2026-27 borrowers requires NSLDS aggregate and lifetime-limit checks performed outside this calculator.
- Aggregate and lifetime limits are only modelled for undergraduate dependent and undergraduate independent tiers.
Verify it yourself
Every published scenario can be replayed against the live engine, and the full input contract is documented in the public API.