It depends. If you are in a community property state like Texas and California, then absent a prenuptial or postnuptial agreement, yes, everything earned and accrued during the marriage is community property and normally would be split 50 50. Anything that you had prior to marriage would be separate property and would not be subject to this 50 50 split rule. If you live in an equitable distribution state, it could be split 50 50 (and often is) if the court deems that this allocation is what is “fair” under the circumstances of your case. Again, as with community property states, you are only concerned with what was earned during marriage. We are not concerned with inheritances and gifts as a general rule under either of these regimes as neither is marital property under the rules of every state in the US (but if you are in the UK they could be a part of the marital res).