Tax Research · Brief · Working level
Is it still good law? Checking currency without a paid citator
Shepard's and KeyCite are conveniences, not necessities. Subsequent-history tracing, IRB status lines, and actions on decision let you verify that a case or ruling is still good law using only free government sources.
A citator — Shepard's, KeyCite, or a tax service's equivalent — answers one question: has anything happened since this authority was issued that changes its weight? Nothing about that question requires a subscription. Reversals, IRS acquiescence and nonacquiescence, and ruling obsolescence are all announced in free government sources; what the paid tools sell is aggregation and a colored flag. Without them, you run the checks manually and record that you did.
The stakes are concrete. Rev. Rul. 58-74 was cited in research-credit memos for sixty years before the IRS obsoleted it in 2023; Little Sandy Coal reads differently after Seventh Circuit affirmance than before. An authority is not "found" until its current status is verified.
Move 1: trace the authority's own history
For a case: search the taxpayer's name in DAWSON at ustaxcourt.gov for later opinions and orders in the same docket (a summary-judgment win can precede a trial loss), then search govinfo.gov's court-opinions collection for the appeal. Note affirmed, reversed, vacated, or remanded — and on which issue, since partial reversals are common. For a regulation: the eCFR source note lists every amending Treasury Decision, so a cite to superseded text is detectable in seconds. For an IRB item: the most recent Bulletin document mentioning it states its status.
Move 2: check the IRS's reaction
Courts are only half the story; the IRS separately announces whether it will follow adverse decisions.
The IRS's published reactions each carry a defined meaning.
| Signal | Where announced | Meaning for your position |
|---|---|---|
| Acquiescence | Internal Revenue Bulletin | IRS will follow the decision nationwide |
| Acquiescence in result only | IRB | Accepts the outcome, rejects the reasoning |
| Nonacquiescence | IRB (via action on decision) | IRS will relitigate outside the losing circuit |
| Revoked / superseded | IRB | Prior ruling has no current force |
| Obsoleted | IRB | Ruling no longer applies (law changed) |
| Modified / clarified / amplified | IRB | Still good law, adjusted — read the later item |
A taxpayer victory under nonacquiescence is fragile authority: your client can cite it, but exam will not concede, and outside the deciding circuit the Golsen dynamics described in How to read a tax case leave the Tax Court free to side with the Service. The memo should say which signal applies — silence from the IRS is itself worth noting.
Move 3: see how later authorities treat it
The forward-citation check paid citators automate: full-text search the case name or ruling number in DAWSON, in govinfo's opinions collection, and in a site-restricted search of irs.gov. What you want is qualitative — do later opinions follow, distinguish, or decline to extend the authority? Three recent opinions distinguishing a case on its facts is a warning no flag color conveys. This is slower than a citator and less complete for older or obscure items; where the position's dollars are large, that residual gap is a fair argument for borrowing an hour of a paid service. Neutrality cuts both ways.
Recording the check
A currency check that isn't documented might as well not have happened. For each authority in the file, record: status as of a stated date, the searches run, and the result ("affirmed CA7 2023; no AOD located as of 2026-06-24"). That line item is what lets the memo support a penalty defense years later — the standard urged in Building a research file, and part of what separates substantial authority from wishful citation under the Section 6662 framework.
Frequently asked questions
- How do I check whether a tax case is still good law without Westlaw or Lexis?
- Trace it manually: search the taxpayer's name in the Tax Court's DAWSON system and govinfo's court-opinions collection for later proceedings and the appeal; search the case name in the Internal Revenue Bulletin for actions on decision, acquiescence, or nonacquiescence; and search later opinions citing it to see whether they follow or distinguish it. Date the check in your file.
- What is an action on decision (AOD)?
- An action on decision is Chief Counsel's published statement of whether the IRS will follow a court decision it lost: acquiescence (will follow), acquiescence in result only, or nonacquiescence (will keep litigating outside the losing circuit). AODs are announced in the Internal Revenue Bulletin and tell you whether a taxpayer-favorable case will actually protect your client at exam.
- How do I know if a revenue ruling has been revoked or obsoleted?
- Later Internal Revenue Bulletin items announce the status change using standard terms — revoked, superseded, modified, amplified, clarified, obsoleted. Search the ruling's number (for example "Rev. Rul. 58-74") across irs.gov/irb and in a general search engine restricted to that site. The most recent item mentioning it states its current status.