Money from USAID, the foreign aid arm of the US government, has to be kept in a separate account, according to Barbara Crane, a former senior advisor to USAID's Office of Population, Reproduction and Health, which is in charge of overseeing compliance with these restrictions. That helps prevent "co-mingling" with other aid money and even inadvertently slipping into a pool of cash that paid for an abortion. "It's so meticulous on the financial side of this," Crane said. "Funds really can't be mixed."
Nils Gade the regional director for East and Southern Africa at Marie Stopes International (MSI), said there's also a coding system that gives every public health activity one — and only one — code. Zero double-dipping allowed.
Many organizations also do their own audits. Some, like Marie Stopes International, even do two audits — one internally, by their own finance staff, and one externally, by an internationally recognized accounting and auditing firm, like Price Waterhouse Coopers. One of the jobs of those outside firms is to make sure that groups like MSI really are following the rules they say they follow.
There's also a lot of oversight from the government. USAID requires any organization that takes its funds to go through compliance training. There are USAID officers in many embassies, and one of their jobs is to make sure groups that use US government money are not violating this rule.
It's almost impossible to cheat this system, or even to accidentally pay for an abortion with US aid dollars. "There’s a lot in place to make sure of that, and it's been in place for decades," Crane said. (There's also the Office of the Ombudsman at USAID, and the General Accounting Office, the watchdog arm of Congress, and USAID's compliance record by both of these groups is "pretty nearly perfect," Crane said.)
And there's punishment, of course: Violate the rule and you could lose all that American funding.