Hi and welcome to JA. I am Ray and will be the expert helping you today.
IRAs and mutual funds pass directly to you as a named beneficiary and are taxable to you.The simple rule here is that if they were deferred at the time they were put in--aka IRAs, etc then you have to pay the income taxes when you receive the disbursement.You may be able to roll them over into your name if you want to put this off.They should give you this option.
Any cash here, houses, cars, etc that are an estate
asset here come tax free as inheritance as long as they are under the $5,430,000 lifetime exclusion for 2015.
Reference to that exclusion..
If the mutual funds here are not retirement accounts--in other words the deceased already paid taxes on them then they are tax free.The institution will tell you because they will want your ssn for tax purposes as they would send you an end of year statement and they report it to IRS as well.
I appreciate the chance to help you today.Please let me know if you have more follow up.Thanks again.