Kyrgyzstan has a few cash machines in its main cities but in general you should bring hard currency with you to change for Som.
In any town, you should find exchange shops willing to trade a variety of currencies. U.S. dollars are still the most common but rates for the euro are also frequently listed along with the Russian rouble and, less often, British pounds. Rates can vary, especially in Bishkek, so it’s worth walking around to find the best deal.
Currency data courtesy coinmill.com
When you find an ATM, it often dispenses U.S. dollars as well as Som. A few dollars are not a bad idea if you’re heading to more remote parts. They will always be the easiest to change and, compared to wads of Kyrgyz Som, dollars are quite compact. You can often pay for hotel bills and other large purchases in hard currency.
Credit cards may be accepted as payment for things like plane tickets but expect to pay a surcharge.