Court bars penalty and interest challenge after taxpayer signs installment agreement

Diego E. Salazar v. Commissioner. U.S. Tax Court. No. 14285-23L. T.C. Memo. 2026-9.

Once a taxpayer accepts an installment agreement in a collection due process (CDP) case, the fight over penalties and interest is over.

Holding

The Tax Court granted summary judgment for the IRS. It held that the taxpayer could not challenge penalties or interest after agreeing to an installment agreement that resolved the liabilities.

Why It Matters

• CDP he…