It sounds like you're taking out a loan in order to make payments for the policy where the entire amount is due of front.
In such a case, you're essentially prepaying for the insurance but you'll usually want to recognize the expense each month, not all up front.
In your case, though, you're also getting a loan, so you have a liability as well.
So, to handle this, create two new accounts, named something like:
- Prepaid Workers Compensation (an asset)
- Workers Compensation Loan (a liability)
Then in one of the registers, record a $15,000 in the register to increase the balance, which will increase the balance for both accounts.
Then, in the Prepaid Workers Compensation account, record a monthly transaction for 1/12th of $15,000, $1,250 and use your WC expense account.
Then, each month, record your $2000 payments until the loan is paid off. If you're being charged interest, then record the interest each month in the Workers Compensation Loan account using an interest expense account.