There are many things you can ignore and procrastinate. A crack in your foundation is NOT one of them. The very first thing you should do (without delay) when you witness a foundation crack, is to check your Homeowners policy. If your policy covers this damage, then it's a "no-brain'r" to get the ball rolling as soon as possible on scheduling repair. If your policy does not cover this damage, then there are potential other outs such as petitioning the Builder's insurance if the house is relatively young.
Regardless the cost of repair is likely to go up exponentially over time. Whether insured or not, we'll help you develop a course of action that limits the damage to both your property and your wallet.