The Savings Deposit Program: A Guaranteed 10% You Have to Claim
There is exactly one place in American finance that pays a guaranteed 10%, and it only exists while you are deployed to a combat zone. Most people either set it up too late or miss it entirely. Here is how to not be one of them.
The bottom line up front
- 1.SDP pays a guaranteed 10% annual interest, compounded monthly, on up to $10,000, available only while deployed to a combat zone.
- 2.You must enroll yourself through deployed finance; it does not start automatically.
- 3.Interest keeps accruing for up to 90 days after you leave the zone, so fund it early and let it ride.
- 4.Every month $10,000 sits in SDP is about $83 of free, guaranteed interest, so being early is worth real money.
- 5.Do SDP and Roth TSP, not one or the other. They do different jobs.
Think about every "high-yield" thing you have ever been pitched. A great savings account pays a few percent. The stock market averages more but it can also drop 30% in a year. Now here is the Savings Deposit Program: a guaranteed 10% annual return, backed by the U.S. government, with zero risk. There is nothing else like it. The only catch is that it exists for one reason and one window only, while you are deployed to a designated combat zone, and you have to set it up yourself.
The single most common deployment-pay regret is realizing on the way home that you could have had a guaranteed 10% sitting on $10,000 the whole time, but you enrolled in month three or never did. So here is exactly how SDP works and how to squeeze everything out of it.
The basics
- The rate. A guaranteed 10% annual interest, compounded monthly. This is a benefit set by law, not a market return, so it does not move.
- The cap. You can deposit up to $10,000 total. At the full 10%, that is roughly $83 of guaranteed interest every month the money sits there.
- The eligibility. You must be deployed to a designated combat zone for at least 30 consecutive days (or at least one day in each of three consecutive months) and be receiving hostile-fire or imminent-danger pay.
The window that makes it powerful
Here is the part that turns SDP from "nice" into "do this immediately." Interest keeps accruing for up to 90 days after you leave the combat zone, then it stops. So the play is to fund it as early as possible during the deployment and let it ride for that 90-day tail before you withdraw.
The math is simple and it rewards being early. Every month your $10,000 sits in SDP is about $83 you would not otherwise earn. On a six-month deployment, funding it in week one versus month three is a difference of a few hundred dollars of free, guaranteed money for doing nothing but filling out the paperwork sooner.
It does not start automatically
Nobody enrolls you in SDP. You set it up through your deployed finance office, and the deposits come out of your pay. If you wait until you are settled in and "get around to it," you have already lost interest you cannot get back. Make it one of the first things you do downrange, not one of the last.
How to actually fund it
You can fund SDP through allotments from your pay, and because your pay in a combat zone is already tax-free under the CZTE, the money going in has not been taxed. The goal is to get to the $10,000 cap as fast as your cash flow allows, since the cap is where the guaranteed return is maxed. If you cannot get to $10,000 right away, fund what you can early and add to it, because partial is still a guaranteed 10% on whatever is in there.
One thing to know about the interest
The interest SDP pays you is taxable income, even though the pay you deposited was tax-free. That does not change the decision at all, since a taxable 10% is still far better than anything else available, but it is worth knowing so the small tax line at the end does not surprise you.
SDP and Roth TSP, not SDP or Roth TSP
People sometimes treat this as a choice between SDP and maxing Roth TSP from their tax-free combat-zone pay. It is not a choice. Do both. SDP is a guaranteed 10% on up to $10,000 with a hard cap, so max it. Roth TSP is your long-term, never-taxed-again retirement money with a much higher ceiling in a combat-zone year. They do different jobs. The members who come home from a deployment in the best shape almost always did both, early.
The bottom line
SDP is a guaranteed 10% on up to $10,000, available only while you are deployed to a combat zone and receiving hostile-fire or imminent-danger pay. It does not start automatically, interest keeps building for 90 days after you leave, and the whole thing rewards being early. Enroll in week one, fund it to the cap as fast as you can, and let it ride. There is no better deal in finance.
See exactly what it compounds to with the SDP Calculator, and fit it into the full picture with the Deployment Pay guide.
Sources
- Savings Deposit Program: DoD FMR Vol 7A, Ch 51
- DFAS: Savings Deposit Program guidance
- 37 U.S.C. § 1035: deposits of savings
Figures reflect 2026 rates and regulations. This guide is general information, not personalized financial or tax advice. Always verify with your finance office or a tax professional before making a decision. How we research and source: our methodology.
FAQ
Frequently asked questions
- How much does SDP pay?
- A guaranteed 10% annual interest, compounded monthly, on up to $10,000 deposited. At the full cap that is roughly $83 of guaranteed interest every month the money sits there. The rate is set by law, so it does not move with the market.
- Who is eligible for the Savings Deposit Program?
- Service members deployed to a designated combat zone for at least 30 consecutive days (or at least one day in each of three consecutive months) who are receiving hostile-fire or imminent-danger pay. You enroll through your deployed finance office.
- How long does SDP keep earning interest after deployment?
- Interest keeps accruing for up to 90 days after you leave the combat zone, then it stops. That is why the smart move is to fund it early during the deployment and let it ride through that 90-day tail before you withdraw.
- Is SDP interest taxable?
- Yes. The interest SDP pays is taxable income, even though the combat-zone pay you deposited was tax-free under the CZTE. It does not change the decision, since a taxable 10% still beats everything else available, but it is worth knowing so the tax line does not surprise you.
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Run your own numbers
REF: Military Toolkit Guides, effective 2026
Official 2026 DoD, DFAS, DTMO, IRS, and VA sources. See each guide’s Sources list
Results are estimates. Always verify with your finance office.