CITES BY TOPIC:  statute of limitations
Derived from:  Tax Procedure and Tax Fraud, Patricia Morgan, West Publishing, p. 96; ISBN 0-314-06586-5
Type of Action Limitation Period I.R.C. §
IRS assessment of tax Generally 3 years after due date of return (or date actually received by IRS, ir later) 6501(a)
Exceptions to normal 3-year limit
1.  No return filed.
2.  Fraudulent return
3. Substantial omission from gross income

No limit
No limit
6 years

6501(c)(3)
6501(c)(1)
6501(e)
Claim for refund of overpaid tax On or before later of: 3 years after return filed or 2 years after tax paid 6511(a)
If statute of limitations was extended by consent: on or before 6 months after expiration of extended period. 6511(c)(2)
Filing suit for refund of overpaid tax Not before: 6 months from date of filing refund claim (with no response from IRS) or date of notice of disallowance. 6532(a)(1)
Not after: 2 years from date notice of disallowance issued or 2 years from date statutory notice of disallowance was waived. 6532(a)(3)