The previous answer is incorrect for Michigan. Agents unfamiliar with the laws in our state should refrain from answering questions that they are unfamiliar with.
Michigan is a redemption state. That means during the six month redemption period you can redeem your house for the amount that was bid at the sheriff's sale. By your question, I am assuming that the lender "underbid" at sheriffi's sale. This would mean that they bid less than what was owed on your mortgage. So, if you pay the amount that they bid plus the interest that is do to them, you would own your house free and clear. Or, if you prefer, you can sell your house and payoff the redemption amount during that sale. If the house sells for more than what you would need to pay the lender, then you get to keep the difference.
For example, I recently had a client who owed $225,000 on their mortgage. The bank, for some unknown reason bid $45,000 at sheriff's sale. We sold the house for $125,000 and the homeowner walked away with a check for about $60,000 after the closing.
The lenders are "underbidding" about 1/3 of the time today. By underbidding they can come after you for the deficiency. So in answer to your question, if you redeem your house, yes they have left their options open to pursue deficiency in the future. Will they do it? That is anyones guess at this point.
Kathy Persha, Realtor
GRI, SRF, CDPE, CIAS
Nextage Advanced Realty