IF you are US military retired, and can maintain benefits such as shopping at base facilities, medical facilities (eg. pick one of the better-rated VA hospitals, although apparently all have been undergoing upgrades over the past 2 yrs or so), you'll want to live in a lower-cost state and near a base. Florida has no state income tax, and homestead exemption, but costs there are rather high. TX has no state income tax, lower cost of living. AZ is popular with retirees.
If you have family, you likely don't want to be too far from them. Hence, you might choose NC, SC instead of AZ, NV, or vice versa. But you absolutely need to live in a lower-cost area of US on such an income. You must avoid West Coast, MA, CT, NY, NJ, and similar very high-cost, high-tax jurisdictions.