skills/complete-veteran-benefits/references/calculations.md

# Ratings and Payment Calculations

## Combined ratings

Obtain each individual service-connected rating, effective period, and laterality
when relevant. A combined rating alone cannot reveal its component ratings.
Do not add percentages arithmetically or infer permanent-and-total status.

Retrieve the applicable [38 C.F.R. § 4.25](https://www.ecfr.gov/current/title-38/chapter-I/part-4/subpart-A/section-4.25)
and use its table and sequence, preserving intermediate table values. Convert
to the final multiple of ten only after the required combinations. A generic
floating-point formula or a programming language's default rounding can differ
from the table. Verify computed results against the actual regulation.

For paired extremities, retrieve [§ 4.26](https://www.ecfr.gov/current/title-38/chapter-I/part-4/subpart-A/section-4.26),
identify qualifying disabilities, and follow the applicable grouping, factor,
and exception rules. Do not apply the bilateral factor to every paired organ
or assume that applying it can never reduce the outcome. Check the legally
applicable exception and most-favorable permitted calculation.

Show individual inputs, intermediate values, bilateral treatment if relevant,
and the final combined evaluation. Keep SMC and TDIU entitlement separate from
this arithmetic. If inputs are incomplete, label each scenario's assumptions.

## Compensation and back pay

Determine legal effective date before estimating payment. Verify payment
commencement separately, including applicable 38 U.S.C. § 5111 and 38 C.F.R.
§ 3.31. Do not equate symptom onset, award effective date, payable month, and
deposit date.

Build a period table with award/rating changes, dependency changes, historical
rates, SMC if applicable, and compensation already paid. Retrieve VA's rate
for each relevant period; do not multiply today's rate across past years.
Identify possible offsets, recoupment, retired-pay interactions, withholding,
and fees from actual facts and governing rules rather than applying a blanket
percentage. Distinguish gross entitlement from estimated net retroactive pay.

| Payable period | New monthly entitlement | Previously paid entitlement | Difference | Months | Gross difference |
| --- | --- | --- | --- | --- | --- |

Use decimal currency arithmetic. State the cutoff month, assumptions, source
rate dates, and unresolved adjustments. Reconcile interval subtotals to the
total and check boundary months. Never call a gross estimate the exact deposit.

## Other benefits

For pension, education, retired pay, insurance, taxes, and healthcare premiums,
use the program's own units, eligibility dates, rate categories, and rounding.
Do not reuse disability-compensation logic. A VA pension asset-transfer question
requires specific current penalty/eligibility research before any strategy is
recommended.