You can get a free TransUnion FICO score through a Bank of America credit card account, select Barclays credit card accounts, and Discover's free Credit Scorecard program (open to all).
You cannot get a free FICO score from TransUnion directly. Instead, TransUnion allows you to view your VantageScore by paying $24.95 per month for a TransUnion account. That gives you unlimited access to your credit score, your credit report, and credit monitoring.
You don't have to pay to check your TransUnion credit score, however, and the credit score you check doesn't have to be a FICO score. You can get free daily credit score updates based on TransUnion credit report data from WalletHub. You can also monitor your credit and receive customized advice based on your credit profile.