Savings Deposit Program (SDP) Calculator
Project the guaranteed 10% return on deployment savings: quarterly compounding, $10,000 cap, and the 90-day post-return interest tail.
By Konstantin Iakovlev · Updated August 2026 · Source: DFAS — Savings Deposit Program
Final Balance
$10,970.82
Guaranteed Interest Earned
$970.82
Total Deposited
$10,000.00
Program Terms
| Guaranteed annual rate | 10% |
| Compounding | Quarterly (2.5%) |
| Principal cap | $10,000.00 |
| Interest accrues after return | 90 days |
You hit the $10,000 principal cap — further deposits are not accepted, but interest keeps compounding on the full balance.
Use the Savings Deposit Program (SDP) Calculator above to calculate your results. Enter your values and see instant results — all calculations run in your browser.
Disclaimer: This calculator is for informational purposes only and does not constitute tax, financial, or legal advice. Results are estimates based on the information you provide and current rates. Always consult a qualified tax professional or financial advisor for advice specific to your situation.
How It Works
The Savings Deposit Program (10 U.S.C. §1035) is the best guaranteed return available to anyone in uniform: while deployed to a designated combat zone or qualifying contingency operation, you can deposit up to $10,000 and earn a flat 10% annual rate, compounded quarterly at 2.5%. No market product touches that risk-free — the closest Treasury yield runs at less than half.
The mechanics this page models: deposits go in monthly (they cannot exceed your unallotted pay for the month), the principal cap is $10,000, interest is credited quarterly on the running balance, and — the part people miss — interest keeps accruing until 90 days after you return, one extra quarter of growth on the full balance. Withdrawal is normally after return; the balance pays out through myPay/DFAS.
Eligibility starts after 30 consecutive days in the designated area (or one day a month for three consecutive months). The 10% interest is taxable — unlike combat-zone pay itself — though it is earned tax-deferred until withdrawal. Fill the $10,000 as early in the deployment as pay allows: every month at cap earns roughly $83 in guaranteed interest.
Example: 9-Month Deployment, $2,500 a Month
- 1 A deployed member allots $2,500 a month to SDP. The $10,000 principal cap is reached in month 4.
- 2 Interest is credited at 2.5% each quarter on the running balance while deployed — three crediting dates across the 9 months.
- 3 After return, the balance earns one more quarter under the 90-day rule before payout.
- 4 Result: $10,000 deposited grows to $10,970.82 — $970.82 of guaranteed, risk-free interest on a nine-month deployment plus the tail.
Source: DFAS — Savings Deposit Program · Last updated: August 2026
Frequently Asked Questions
What interest does the Savings Deposit Program pay?
Who is eligible for SDP?
Is SDP interest taxable?
When can I withdraw SDP money?
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